Incidence rates of atopic dermatitis, asthma, and allergic rhinoconjunctivitis in Danish and Swedish children

Superantigen Encoding Genes in Staphylococcus aureus Isolated from Lesional Skin, Non-Lesional Skin, and Nares of Patients with Atopic Dermatitis

Patients with atopic dermatitis (AD) are more likely than healthy individuals to harbour Staphylococcus aureus on their skin. Superantigens (SAgs) produced by specific S. aureus strains may contribute to AD-associated skin inflammation. The present study compared the prevalence and types of SAg-encoding genes between S. aureus isolated from patients with AD and from  controls, and within the AD group between isolates from different sampling sites (lesional skin, non-lesional skin, and nares). This retrospective case-control study extracted data from 2 previous studies that examined S. aureus using whole-genome sequencing. The 138 S. aureus isolates obtained from 71 AD patients contained 349 SAg-encoding genes; 22 (6.3%) were found in isolates from nares (0.4 ± 0.6 genes per isolate), 99 (28.4%) in isolates from non-lesional skin (3.7 ± 3.9), and 228 (65.3%) in isolates from lesional skin (4.2 ± 4.5). S. aureus (n = 101) from the control group contained 594 SAg-encoding genes (5.9 ± 4.2). Of the S. aureus isolated from lesional AD skin, 69% carried at least 1 gene encoding SAg compared with 33% of AD nasal isolates. SAg could be a factor in the pathogenesis of a subset of AD patients.

Referral Pathways for Children with Atopic Diseases in Denmark

Atopic diseases such as atopic dermatitis, food allergy, allergic rhinoconjunctivitis, and/or asthma are common. In Denmark, however, there are multiple referral pathways for these diseases in the healthcare system and they are poorly understood. To describe how children with atopic diseases navigate their way through the Danish healthcare system, a questionnaire was distributed to children aged ≤ 17 years, who were being treated for atopic diseases between August 2020 and June 2021, either by a practising specialist or a hospital department, in the Capital Region of Denmark. A total of 279 children completed the questionnaire and most were referred to a specialist or to a hospital by their general practitioner. No "common track" to hospital existed for patients with ≥ 3 atopic diseases. These patients were more often referred to a hospital compared with children with 2 atopic diseases or fewer (odds ratio [OR] 3.79; 95% CI 2.07-7.24). The primary determinants for hospital treatment were food allergy (OR 4.69; 95% CI 2.07-10.61) and asthma (OR 2.58; 95% CI 1.18-5.63). In conclusion, children with multiple atopic diseases were more likely to be referred to hospital departments than to practising specialists, mainly due to food allergies.

Improving Clinical Practice Through Patient Registries in Allergy and Immunology

Patient registries are a mechanism for collecting data on allergic and immunologic diseases that provide important information on epidemiology and outcomes that can ultimately improve patient care. Key criteria for establishing effective registries include the use of a clearly defined purpose, identifying the target population and ensuring consistent data collection. Registries in allergic diseases include those for diseases such as inborn errors of immunity (IEI), food allergy, asthma and anaphylaxis, pharmacological interventions in vulnerable populations, and adverse effects of pharmacologic interventions including hypersensitivity reactions to drugs and vaccines. Important insights gained from patient registries in our field include contributions in phenotype and outcomes in IEI, the risk for adverse reactions in food-allergic patients in multiple settings, the benefits and risk of biologic medications for asthma during pregnancy, vaccine safety, and the categorization and genetic determination of risk for severe cutaneous adverse reactions to medications. Impediments to the development of clinically meaningful patient registries include the lack of funding resources for registry establishment and the quality, quantity, and consistency of available data. Despite these drawbacks, high-quality and successful registries are invaluable in informing clinical practice and improving outcomes in patients with allergic and immunological diseases.

A Patient-Centered Approach to Vernal Keratoconjunctivitis (VKC): A Podcast

Vernal keratoconjunctivitis (VKC) is a rare yet severe form of allergic conjunctivitis predominantly affecting children, mainly boys, with a global prevalence and a higher incidence in certain geographical regions. The disease is characterized by seasonal exacerbations. VKC presents with ocular surface inflammation leading to various distressing symptoms such as itching, redness, mucous discharge, and pain. The disease primarily manifests bilaterally, though it may initially appear unilaterally. If left untreated, VKC can result in corneal complications, including shield ulcers and vision impairment, affecting daily activities and psychosocial well-being, especially in children. The diagnosis of VKC involves identifying key clinical findings on the ocular surface such as Tranta dots, giant papillae, or shield ulcers. Management follows a stepwise approach, including anti-allergic eye drops, steroid eye drops, and topical medications like cyclosporine, which may take up to 3 months to show efficacy. Allergic sensitization, often to inhaled allergens like pollen and house dust mites, is associated with VKC in half of the cases. Understanding and managing these allergies through measures such as avoidance, sensitization control, and co-treatment of associated conditions like asthma and rhinoconjunctivitis are essential in VKC management. Atopic keratoconjunctivitis (AKC), a related condition associated with atopic dermatitis and asthma, shares similarities with VKC but typically affects young adults. However, there is an observed spectrum between the two diseases, indicating similar treatment strategies for both. VKC treatment requires a patient-centered approach, involving informed and supported parents, considering economic factors due to costly eye drops, and ensuring accessibility and practicality of treatment, especially in children. A multidisciplinary team collaboration, including ophthalmologists, pediatricians, and dermatologists, optimizes patient care. The rewarding aspect of VKC treatment lies in witnessing children regain their quality of life, overcome vision challenges, and thrive in their daily activities. In conclusion, understanding VKC, its associated allergies, and employing a comprehensive, patient-centered approach are crucial in managing this challenging condition, particularly in children, to enhance their vision and overall well-being.

Association between atopic disease and vaccination granulomas: A nested case-control study

BACKGROUND

Vaccination granulomas are observed in 1% of all children vaccinated with an aluminium-adsorbed vaccine. Most children with granulomas also have aluminium contact allergy (CA). CA and atopic diseases are both highly prevalent among children and may be associated.

OBJECTIVE

To investigate the association between vaccination granulomas and atopic dermatitis (AD), asthma and rhinitis in children.

METHODS

We sourced a cohort of all Danish children born from 2009 to 2017 and conducted a nested case-control study, with cases defined as children with vaccination granulomas, matched to controls 1:10 on sex, socioeconomic class, gestational age and season of birth. All cases and controls were vaccinated with aluminium-adsorbed vaccines and followed until their second birthday. We used conditional logistic regression to estimate the odds ratios (ORs).

RESULTS

The study included 2171 cases with vaccination granulomas, and 21 710 controls. Children with a diagnosis of AD had a significantly higher risk of a vaccination granuloma (OR 1.50, 95% confidence intervals [CI] 1.25-1.80). No significant association was found between granulomas and asthma or rhinitis. The association between granulomas and AD was even higher in an additional sensitivity-analysis, following the children until their fourth birthday (OR 2.71, 95% CI 2.36-3.11).

CONCLUSION

AD was significantly associated with vaccination granulomas, but not with other atopic diseases, within both the first 2 and 4 years of life.

The effectiveness of pollen allergen immunotherapy on allergic rhinitis over 18 years: A national cohort study in Denmark

BACKGROUND

Because long-term effectiveness of pollen allergen immune therapy (AIT) for allergic rhinitis (AR) is not well-described, we studied effectiveness over 18 years in Denmark.

METHODS

A register-based cohort study using data on filled prescriptions, 1995-2016, Denmark. In a cohort of 1.1 million intranasal corticosteroid inhaler users (proxy for AR), we matched users treated with grass, birch or mugwort AIT 1:2 with non-treated users on baseline year and 24 characteristics in the 3 years prior to baseline. The primary outcome was the odds ratio (OR) of using anti-allergic nasal inhaler during the pollen season in the treated versus non-treated group by years since baseline.

RESULTS

Among 7760 AR patients treated with pollen AIT, the OR of using nasal inhaler 0-5 years after baseline was reduced when compared with 15,520 non-treated AR individuals (0-2 years, OR 0.84 (0.81-0.88); 3-5 years, OR 0.88 (0.84-0.92)), but was close to unity or higher thereafter (6-9 years, OR 1.03 (0.97-1.08); 10-18 years, OR 1.18 (1.11-1.26)). In post hoc analyses, results were more consistent for those who already had 3 of 3 baseline years of use, and in patients using nasal inhaler in the latest pollen season (0-2 years, OR 0.76 (0.72-0.79); 3-5 years OR 0.86 (0.81-0.93); 6-9 years, OR 0.94 (0.87-1.02); 10-18 years, OR 0.94 (0.86-1.04)) as opposed to no such use.

CONCLUSIONS

Patients treated with pollen AIT in routine care to a higher degree stopped using anti-allergic nasal inhaler 0-5 years after starting the standard 3 years of therapy, and not beyond 5 years. Post hoc analyses suggested effectiveness was more consistent among patients with persistent AR.

Comorbidity Between Inflammatory Bowel Disease and Asthma and Allergic Diseases: A Genetically Informed Study

BACKGROUND

Little is known about shared origins between inflammatory bowel disease (IBD) and allergic diseases (asthma, allergic rhinitis, and eczema). We aimed to expand current knowledge on the etiological sources of comorbidities between these disorders using a range of genetically informed methods.

METHODS

Within-individual and familial co-aggregation analysis was applied to 2 873 445 individuals born in Sweden from 1987 to 2014 and their first- and second-degree relatives. Quantitative genetic modeling was applied to 38 723 twin pairs to decompose the genetic and environmental sources for comorbidity. Polygenic risk score analysis between IBD and allergic diseases was conducted in 48 186 genotyped twins, and linkage disequilibrium score regression was applied using publicly available data to explore the genetic overlap.

RESULTS

IBD was associated with asthma (adjusted odds ratio [aOR], 1.35; 95% confidence interval [CI], 1.30 to 1.40), allergic rhinitis (aOR, 1.27; 95% CI, 1.20 to 1.34), and eczema (aOR, 1.47; 95% CI, 1.38 to 1.56), with similar estimates for ulcerative colitis or Crohn's disease. The ORs for familial co-aggregation decreased with decreasing genetic relatedness. Quantitative genetic modeling revealed little evidence of common genetic factors between IBD and allergic diseases (eg, IBD and allergic rhinitis; genetic correlation ra = 0.06; 95% CI, -0.03 to 0.15) but did reveal some evidence of unique environmental factors between IBD and eczema (re = 0.16; 95% CI, 0.00 to 0.32). Molecular genetic analyses were similarly null for IBD and allergic diseases, except for a slight association between Crohn's disease polygenic risk score and eczema (OR, 1.09; 95% CI, 1.06 to 1.12).

CONCLUSIONS

We found little evidence to support a shared origin between IBD and any allergic disease but weak evidence for shared genetic and unique environmental components for IBD and eczema.

Maternal mental health disorders and offspring asthma and allergic diseases: The role of child mental health

BACKGROUND

Maternal psychological stress during pregnancy and postnatally has been shown to be associated with offspring atopic diseases (asthma, atopic dermatitis and allergic rhinitis). The aim of this study was to assess whether this association may be attributable to the child's own mental health disorders.

METHOD

The study population included 15,092 twin children born 2002-2010 in Sweden. Questionnaire data at age 9 years was linked to national patient- and prescription registers. Maternal mental health during pregnancy and 3 years postnatally were identified from diagnosis and medication data (depression, anxiety and stress disorders). Atopic diseases in children were identified from questionnaires, diagnosis and medication data. Child mental health status (depression and anxiety) was identified from questionnaires. Three-way decomposition methods tested for mediation or interaction by child mental health disorders.

RESULTS

Maternal mental health disorders were associated with most child atopic diseases including asthma aRR1.36 (95% CI 1.12, 1.60), and child mental health disorders, aRR1.73 (95% CI 1.56, 1.92). Children with mental health disorders were comorbid for atopic diseases with only asthma reaching statistical significance, aRR1.29 (95% CI 1.14, 1.47). Three-way decomposition found that mediation or interaction by child mental health disorders did not account for the mother mental health and child atopy associations except in parent-report asthma, where child mental health disorders mediated 13.4% (95% CI 2.1, 24.7) of the effect, but not for objectively defined (diagnosis and medication) asthma.

CONCLUSION

The associations between maternal mental health and child asthma and allergic diseases do not appear to be attributable to child mental health disorders.

Trends of Diagnosis, Disease Course, and Treatment of Atopic Dermatitis 2012-2021: Real-World Data from a Large Healthcare Provider

In the last decade, new treatments for atopic dermatitis (AD) have emerged. We aimed to describe trends of the diagnosis, disease course, and treatment of AD over a decade (2012-2021) using data from Maccabi Healthcare Services (a 2.7-million-member healthcare provider in Israel). The AD prevalence was stable (4.0% on 31 December 2021 vs. 4.3% on 31 December 2012). The annual AD incidence was also stable (5.8/1000 in 2012 and 5.7/1000 in 2021). AD-related treatment use was highest in the first year post-diagnosis, and it included, among children (n = 87,414) vs. adults (n = 36,865), low-potency topical corticosteroids (TCS) (41.8% vs. 27.1%), mid-potency TCS (30.1% vs. 28.1%), high-potency TCS (34.9% vs. 60.3%), topical calcineurin inhibitor (10.8% vs. 10.1%), phosphodiesterase-4-inhibitor (0.3% vs. 0.7% overall; approved in 2019), phototherapy (0.1% vs. 2.3%), and systemic/biologic treatments (13.0% vs. 13.3%). Among children diagnosed in 2012 and followed through to 2021 (n = 5248), 21.5% had ≥1 AD diagnosis/treatment 10 years later (among 3223 adults: 38.3%). We conclude that the incidence and prevalence rates of AD were comparable to those in similar database studies and remained relatively stable over the past decade. The results underscore the burden of medication use among children and adults, particularly in the first year after AD diagnosis, and the low rate of AD diagnosis among patients originally diagnosed as children 10 years earlier.

No associations between type 1 diabetes and atopic dermatitis, allergic rhinitis, or asthma in childhood: a nationwide Danish case-cohort study

Studies examining the association between type 1 diabetes (T1D) and atopic diseases, i.e., atopic dermatitis, allergic rhinitis and asthma have yielded conflicting results due to different algorithms for classification, sample size issues and risk of referral bias of exposed cohorts with frequent contact to health care professionals. Using Danish national registries and well-established disease algorithms, we examined the bidirectional association between T1D and atopic diseases in childhood and adolescence using Cox Proportional Hazard regression compared to two different unexposed cohorts from a population of 1.5 million Danish children born from 1997 to 2018. We found no associations between T1D and atopic dermatitis, allergic rhinitis, or asthma (defined after age five). However, in multivariable analysis we found an increased risk of persistent wheezing (defined as asthma medication before age five) after T1D with an adjusted hazard ratio (aHR) of 1.70 [1.17-2.45]. We also identified an increased risk of developing T1D after persistent wheezing with aHR of 1.24 [1.13-1.36]. This study highlights similar risks of atopic diseases in children with T1D and of T1D in children with atopic disease after age of five years versus healthy controls. However, more research is needed to understand the possible early immunological effects of the link between persistent wheezing and T1D.

Antiasthmatic prescriptions in children with and without congenital anomalies: a population-based study

OBJECTIVES

To explore the risk of being prescribed/dispensed medications for respiratory symptoms and breathing difficulties in children with and without congenital anomalies.

DESIGN

A EUROlinkCAT population-based data linkage cohort study. Data on children with and without congenital anomalies were linked to prescription databases to identify children who did/did not receive antiasthmatic prescriptions. Data were analysed by age, European region, class of antiasthmatic, anomaly, sex, gestational age and birth cohort.

SETTING

Children born 2000-2014 in six regions within five European countries.

PARTICIPANTS

60 662 children with congenital anomalies and 1 722 912 reference children up to age 10 years.

PRIMARY OUTCOME MEASURE

Relative risks (RR) of >1 antiasthmatic prescription in a year, identified using Anatomical Therapeutic Chemical classification codes beginning with R03.

RESULTS

There were significant differences in the prescribing of antiasthmatics in the six regions. Children with congenital anomalies had a significantly higher risk of being prescribed antiasthmatics (RR 1.41, 95% CI 1.35 to 1.48) compared with reference children. The increased risk was consistent across all regions and all age groups. Children with congenital anomalies were more likely to be prescribed beta-2 agonists (RR 1.71, 95% CI 1.60 to 1.83) and inhaled corticosteroids (RR 1.74, 95% CI 1.61 to 1.87). Children with oesophageal atresia, genetic syndromes and chromosomal anomalies had over twice the risk of being prescribed antiasthmatics compared with reference children. Children with congenital anomalies born <32 weeks gestational age were over twice as likely to be prescribed antiasthmatics than those born at term (RR 2.20, 95% CI 2.10 to 2.30).

CONCLUSION

This study documents the additional burden of respiratory symptoms and breathing difficulties for children with congenital anomalies, particularly those born preterm, compared with children without congenital anomalies in the first 10 years of life. These findings are beneficial to clinicians and healthcare providers as they identify children with greater morbidity associated with respiratory symptoms, as indicated by antiasthmatic prescriptions.

Laboratory mice with a wild microbiota generate strong allergic immune responses

Allergic disorders are caused by a combination of hereditary and environmental factors. The hygiene hypothesis postulates that early-life microbial exposures impede the development of subsequent allergic disease. Recently developed "wildling" mice are genetically identical to standard laboratory specific pathogen-free (SPF) mice but are housed under seminatural conditions and have rich microbial exposures from birth. Thus, by comparing conventional SPF mice with wildlings, we can uncouple the impact of lifelong microbial exposures from genetic factors on the allergic immune response. We found that wildlings developed larger populations of antigen-experienced T cells than conventional SPF mice, which included interleukin-10-producing CD4 T cells specific for commensal Lactobacilli strains and allergy-promoting T helper 2 (TH2) cells. In models of airway exposure to house dust mite (HDM), recombinant interleukin-33, or Alternaria alternata, wildlings developed strong allergic inflammation, characterized by eosinophil recruitment, goblet cell metaplasia, and antigen-specific immunoglobulin G1 (IgG1) and IgE responses. Wildlings developed robust de novo TH2 cell responses to incoming allergens, whereas preexisting TH2 cells could also be recruited into the allergic immune response in a cytokine-driven and TCR-independent fashion. Thus, wildling mice, which experience diverse and lifelong microbial exposures, were not protected from developing pathological allergic immune responses. Instead, wildlings mounted robust allergic responses to incoming allergens, shedding new light on the hygiene hypothesis.

Epidemiology of Allergic Rhinitis in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Allergic rhinitis (AR) is associated with significant clinical and socioeconomic burdens. It is a frequent risk factor for other atopic diseases, such as asthma. Thus, a comprehensive updated description of the epidemiology of AR in the pediatric population is needed to understand its implications better.

OBJECTIVE

To determine the incidence, prevalence, and epidemiology of AR among children over the past 10 years.

METHODS

We conducted a systematic review and meta-analysis using a protocol registered and published with the International Prospective Register of Systematic Reviews (Register No. CRD42022332667). We searched databases, registers, and Web sites for cohort or cross-sectional studies published between 2012 and 2022, evaluating the epidemiology (incidence or prevalence) of AR in the pediatric population. We assessed study quality of and risk for bias using items derived from the Strengthening the Reporting of Observational Studies in Epidemiology statement.

RESULTS

Twenty-two studies were included in the analysis. The overall prevalence of physician-diagnosed AR was 10.48%, the overall prevalence of self-reported current (past 12 months) AR was 18.12%, and the overall prevalence of self-reported lifetime AR was 19.93%. The incidence could not be determined. The analysis of prevalence of AR over time showed a rising trend in physician-diagnosed AR over the years (8.39% in 2012 to 2015 vs 19.87% in 2016 to 2022).

CONCLUSIONS

Allergic rhinitis has significant impacts on the pediatric population, with an increasing trend for diagnosed AR over the years. Further investigations concerning the incidence, comorbidities, diagnosis, and treatment are needed to provide a complete overview of the disease as well as its burden and management.

Trends in incidence of atopic disorders in children and adolescents - Analysis of German claims data

Background

This claims-based study aimed to assess recent nationwide trends in pediatric incidence of atopic diseases in Germany.

Methods

Incidence of atopic dermatitis, asthma, and hay fever was assessed from 2013 to 2021 in annual cohorts of 0- to 17-year-old children and adolescents with statutory health insurance (N = 11,828,525 in 2021).

Results

Incidence of atopic dermatitis remained largely unchanged (15.2 cases per 1000 children in 2021) while hay fever incidence exhibited a fluctuating trend over the study period and amounted to 8.8 cases per 1000 in 2021. Asthma incidence decreased gradually between 2013 (12.4/1000) and 2019 (8.9/1000). This downward trend was followed by a further disproportionate reduction from 2019 to 2020 (6.3/1000) and a re-increase in 2021 (7.2/1000).

Conclusion

The findings complement nationwide prevalence surveys of atopic diseases in children and adolescents in Germany. Knowledge about temporal variations in risk of atopic diseases are crucial for future investigations of explanatory factors to enhance the development of preventive measures. While asthma incidence followed a declining trend throughout the study period, an unprecedentedly strong reduction in pediatric asthma risk was observed in 2020, the first year of the COVID-19-pandemic.

Systematic exploration of eczema-associated paediatric diseases in a Chinese population of millions: A retrospective observation study

BACKGROUND

Eczema is the most common form of dermatitis and also the starting point of atopic march. Although many eczema-associated allergic and immunologic disorders have been studied, there remains a gap in the systematic quantitative knowledge regarding the relationships between all childhood disorders and eczema. This study aimed to systematically explore eczema-associated childhood diseases using a real-world, long-term clinical dataset generated from millions of children in China.

METHODS

Data were collected at 8,907,735 outpatient healthcare visits from 2,592,147 children between January 1, 2013, and August 15, 2019, at the largest comprehensive pediatric medical center in Zhejiang Province of China. The period prevalence differences in various pediatric diseases between children with and without eczema were used to test the independence of various pediatric disorders and eczema using Fisher's exact test. Bonferroni correction was used to adjust the p value in multiple testing. Odds ratio >2 with 95% confidence interval not including 1 and adjusted p < 0.05 was used to identify eczema-associated diseases.

RESULTS

Overall, 234 pediatric disorders were identified from more than 6000 different pediatric disorders. An interactive eczema-associated disease map that has related quantitative epidemiological features called ADmap was published at http://pedmap.nbscn.org/admap. Thirty-six of these disease associations have not been reported in previous studies.

CONCLUSION

This systematic exploratory study confirmed the associations of many well-known diseases with eczema in Chinese children and also identified some novel and interesting associations. These results are valuable for the development of a comprehensive approach to the management of eczema in childhood.

Trends (2007-2019) of major atopic diseases throughout the life span in a large Mexican population

Background

Major atopic diseases such as atopic dermatitis (AD), allergic rhinitis (AR), and asthma share the same atopic background, but they often show differences in their epidemiological behavior.

Objective

We aimed to report the profile of these atopic diseases in a large Mexican population, including their age-related incidences, male:female (M:F) ratios, recent time trends, and association with altitude.

Methods

Registries from the largest, nationwide health institution in Mexico (more than 34 million insured subjects), were reviewed. New cases of AD, AR, and asthma diagnosed each year by family physicians from 2007 to 2019 were adjusted by the corresponding insured population to estimate incidence rates.

Results

Incidences of the 3 atopic diseases were highest in the 0-4 years age-group and progressively decreased thereafter until adolescence. Asthma and AR, but not AD, were more frequent in males during childhood (M:F ratios of 1.5, 1.3, and 0.95, respectively), but predominated in females during adulthood (M:F ratios of 0.52, 0.68, and 0.73, respectively). Time trends showed an initial increasing trend of annual incidences, with a peak around 2009-2011, and a downward trend afterward. This decreasing trend was seen in all age-groups and was more evident for AD (∼50% drop) and asthma (∼40% drop) than for AR (∼20% drop). Geographical distribution suggested that incidences of asthma and AR, but not of AD, had an inverse association with altitude.

Conclusion

Annual incidences of the 3 major atopic diseases have declined in recent years in almost all age groups, and their epidemiological profile during the life span showed contrasting differences according to age, sex, and ecological association with altitude, mainly regarding AD.

Mode of delivery and offspring atopic dermatitis in a Swedish nationwide study

BACKGROUND

Atopic dermatitis is a common chronic childhood disease associated with significant morbidity and healthcare costs. There is a known association between caesarean section and asthma, but the relationship between caesarean section and offspring atopic dermatitis remains uncertain.

METHODS

We conducted a register-based nationwide cohort study including children born in Sweden between January 2006 and December 2018. Data on health and socioeconomic variables were extracted from the national registers for children aged ≤5 years. Time-to-event analyses were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) adjusting for confounders and familial factors.

RESULTS

1,399,406 children were included (6,029,542 person-years at risk). Atopic dermatitis was observed in 17.2% of the 1,150,896 children born by vaginal delivery and 18.3% of the 248,510 born by caesarean section. The mean age of onset of atopic dermatitis was 2.72 years (SD 1.8). Birth by caesarean section was associated with a higher risk of atopic dermatitis (adj-HR 1.12, 95% CI: 1.10-1.14). A higher risk of atopic dermatitis was found in children born by instrumental vaginal delivery (adj-HR 1.10, 1.07-1.13); emergency caesarean section (adj-HR 1.12, 1.10-1.15), and elective caesarean section (adj-HR 1.13, 1.10-1.16) than uncomplicated vaginal delivery in children <1 year of age. Similar hazards were observed in those ≥1 year of age. In sibling control analysis, greater risks remained in children aged <1 year but not in age ≥1 year.

CONCLUSIONS

In our study population, it was observed that children born by caesarean section or instrumental vaginal delivery were at higher risk of early childhood atopic dermatitis. Although familial confounding attenuates the risk in children aged ≥1 year, this was not observed in the first year of life.

Does childhood exposure to biodiverse greenspace reduce the risk of developing asthma?

The prevalence of inflammatory diseases is increasing in populations throughout the industrialized world. An increasing proportion of human populations grow up and live in urban areas, probably with reduced exposure to biodiversity, including diverse soil biotas. Decreased exposure to microorganisms from natural environments, in particular in early childhood, has been hypothesized to hamper development of the human immune system and lead to increasing risks of inflammatory diseases, such as asthma. We investigated 40,249 Danish individuals born 1995-2015. Percentage greenspace was assessed in a 2 km buffer around home addresses of individuals. The Danish Biodiversity Map, charting occurrence density of red-listed animals, plants and macrofungi, was used as a proxy for multi-taxon biodiversity. For asthma defined broadly, we found no evidence of decreasing risk of developing asthma with higher levels of biodiversity, while greenspace exposure was associated with higher risk of asthma. In contrast, exposure to total and biodiverse greenspace was associated with reduced risk of developing severe asthma. Exposure to farmland, which in Denmark is heavily industrialized cropland, also showed association with elevated risk of developing asthma, even at relatively low agricultural landcover. In the subset of children growing up in highly urbanized settings, we found high exposures to urban greenspace to be associated with reduced risk of developing asthma. Our results lend limited support to the hypothesis that childhood exposure to biodiverse environments reduces the risk of acquiring inflammatory diseases later in life. However, access to urban greenspace, such as parks, which typically harbour low levels of biodiversity, seems to reduce asthma risk, potentially through exposure to common soil microbiota. Our results suggest that effects of biodiversity exposure on human health is set by a balance between ecosystem services and disservices and that biodiversity conservation is best motivated with other arguments than reduction of risks from inflammatory diseases.

RNA Sequencing Reveals the Regulation Mechanism of Yunnan Baiyao in Treating Skin Infection Caused by Staphylococcus aureus

Yunnan Baiyao is a well-known traditional Chinese medicine that can be formulated into a powder or capsule form. The mechanism by which it exerts its anti-inflammation effect, which is used in skin care products, needs to be further explored. In this study, we established the Staphylococcus aureus-induced mouse skin inflammatory model to investigate the effects of Yunnan Baiyao by the method of RNA-sequencing technology. The mice were randomly assigned to three groups, and those were control, model, and the Yunnan Baiyao-treated (YNtreated) group. Key genes and pathways were identified using bioinformatics analyses. In the study, we obtained 1,053 differentially expressed genes (DEGs) induced by Yunnan Baiyao. The 233 upregulated genes were enriched in 32 GO terms and 5 KEGG pathways, focused on the items, such as wound healing, cell metabolism, and proliferation, indicating the accelerating effects of Yunnan Baiyao on these aspects. The 820 downregulated genes were enriched mainly in the items, including the regulation of inflammation factor production, immune responses, and regulation of structure dermal components. Besides, Yunnan Baiyao reversed the expressions of 277 (201 decreased and 76 increased DEGs, respectively) induced by S. aureus. Ten key regulatory nodes (MMP2, PLK1, CCNB1, TLR4, CDK1, CCNA2, CDC25C, PDGFRA, MYOC, and KNG1) were identified by the construction of the protein interaction network, half of which were related to cell proliferation. VAV1 was another hub node that was affected by Yunnan Baiyao (Top 20). In the study, VAV1 and TLR4 can be considered key module genes in inflammation regulation. In conclusion, this study found that Yunnan Baiyao can significantly relieve inflammatory symptoms by regulating genes and pathways involved in the regulation of inflammation and immune response and also helped to deepen our understanding of the associated molecular mechanisms.

Skin Dialogues in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic skin disorder associated with significant quality-of-life impairment and increased risk for allergic and non-allergic comorbidities. The aim of this review is to elucidate the connection between AD and most common comorbidities, as this requires a holistic and multidisciplinary approach. Advances in understanding these associations could lead to the development of highly effective and targeted treatments.

Epidemiology and Economic Burden of Atopic Dermatitis: Real-World Retrospective Data from a Large Nationwide Israeli Healthcare Provider Database

Introduction

Real-world data on the epidemiology and economic burden of atopic dermatitis (AD) are limited. Here we describe the epidemiology and economic burden of AD using electronic healthcare data from Israel.

Methods

A retrospective study was performed using the Maccabi Healthcare Services database. AD incidence in 2008–2017 and point prevalence (AD_prev) on 31 December 2017 were described using diagnosis codes for overall patients, and sex and age subgroups. For AD_prev, severity was defined using recently dispensed treatments for AD. Annual healthcare resource utilization in AD prevalent patients was compared with non-AD matched controls using generalized linear modelling. Direct annual costs were estimated also.

Results

AD incidence was 7.0/1000 person-years; overall prevalence was 4.4% (female patients 4.5%, male patients 4.3%; age 0 to less than 6 months, 0.9%; 6 months to less than 12 years, 11.0%; 12 to less than 18 years, 5.8%; 18 years or older, 2.2%). Among AD_prev (n = 94,483), mild, moderate, and severe AD comprised 57.7%, 36.2%, and 6.1% (adults 43.8%, 46.3%, 9.9%), respectively. Dermatologist and allergist visits and hospitalization rates (at least one) were 40.7%, 6.6%, and 3.8% in 2017. Compared with controls, overall and moderate-to-severe AD were associated with 36% and 52% increases in annual per-person costs (incremental costs $126 and $190).

Conclusions

AD epidemiology in Israel is comparable with other real-world database studies. AD imposes an economic burden that increases with disease severity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02120-6.

Occurrence and costs of atopic dermatitis in Israel

Atopic dermatitis is a disease that causes the skin to be inflamed and itchy. Atopic dermatitis is most common in children but can also occur in adolescents and adults. Using data from a large healthcare provider in Israel, this study aimed to describe how common atopic dermatitis is within the population. Costs related to the use of healthcare services (such as visits to dermatologists and creams to treat atopic dermatitis) in the year 2017 were compared between persons with versus without atopic dermatitis. For the years 2008 to 2017, approximately 7 out of 1000 people were newly diagnosed with atopic dermatitis each year (incidence). Among people alive on 31 December 2017, 4.4% had atopic dermatitis (prevalence), with 42.3% suggestive of moderate to severe disease. Patients with atopic dermatitis, particularly those with more severe disease, used healthcare services more frequently. Compared with people without atopic dermatitis, medical costs among patients with atopic dermatitis were 36% higher (corresponding to added costs of $126 per person per year). This study helps to better understand how many people have atopic dermatitis, and what healthcare resources are needed to manage this disease.

Atopic heredity modifies the association between maternal vitamin D status in pregnancy and the risk of atopic disease in childhood: an observational study

Background

The relationship between maternal vitamin D status in pregnancy and the development of atopic diseases in the offspring has been frequently studied, but with contradictory results. Previous studies have found an inverse relation between maternal vitamin D in pregnancy and the risk of atopic diseases in the child. In contrast, others have found a higher maternal 25OHD to be related to a higher risk of atopic diseases. Thus, the aim was to investigate the associations between maternal vitamin D status and intake in pregnancy with asthma, eczema and food allergies in the children up to 5 years. In addition, effect modification by reported atopic heredity was studied.

Methods

Participants in the GraviD study had 25-hydroxyvitamin D (25OHD) analyzed in serum in early (T1) and late (T3) pregnancy. Maternal dietary vitamin D intake was estimated from a short food frequency questionnaire and supplement use by questionnaires. At 5 years of age the child´s history of asthma, eczema and food allergy, including atopic heredity, was reported by questionnaire. Multivariable logistic regression was used.

Results

The cumulative incidence of asthma was 13%, eczema 22%, and food allergy 18%. Only among children without reported atopic heredity, maternal 25OHD of 50–75 nmol/L in T1 was associated with lower odds of asthma (OR 0.271, 95% CI 0.127–0.580), compared to maternal 25OHD > 75 nmol/L. Additionally in these children, maternal 25OHD in T3 (continuous) was associated with asthma (OR 1.014, 95% CI 1.002–1.009), and dietary vitamin D intake with eczema (OR 1.141, 95% CI 1.011–1.288).

Conclusions

Among children without reported atopic heredity, higher maternal vitamin D status and intake during pregnancy was associated with increased risk of reported atopic disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-022-00787-9.

Gene Expression Profile Analyses of the Skin Response of Balb/c-Nu Mice Model Injected by Staphylococcus aureus

Background

Pathogenesis and persistence of many skin diseases are related to Staphylococcus aureus (S. aureus) colonization. S. aureus infection can cause varying degrees of changes in cell gene expression, resulting in complex changes in cell phenotype and finally changes in cell life activities.

Materials and Methods

The transcriptomes of healthy and Staphylococcus aureus (S. aureus)-infected murine skin tissues were analyzed. We identified 638 differentially expressed genes (DEGs) in the infected tissues compared to the control samples, of which 324 were upregulated and 314 were downregulated, following the criteria of P < 0.01 and |log₂FC| > 3. The DEGs were functionally annotated by Gene Ontology (GO), KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway and the protein–protein interaction (PPI) network analyses.

Results

The upregulated DEGs were mainly enriched in GO terms, such as response to stimulus, immune system process and signal transduction, as well as in the complement and coagulation cascade pathway. Thus, S. aureus infection likely activates these pathways to limit the influx of neutrophils and prevent skin damage. Four clusters were identified in the PPI network, and the major hubs were mainly related to cell cycle and proliferation, and mostly downregulated. The expression levels of Nox4, Mmrn1, Mcm5, Msx1 and Fgf5 mRNAs were validated by qRT-PCR and found to be consistent with the RNA-Seq data, confirming a strong correlation between the two approaches.

Conclusion

The identified genes and pathways are potential drug targets for treating skin inflammation caused by S. aureus and should be investigated further.

Validation of Patient Identification Algorithms for Atopic Dermatitis Using Healthcare Databases

INTRODUCTION

The use of real-world data offers a possibility to perform large-scale epidemiological studies in actual clinical settings. Despite their many advantages, administrative databases were not designed to be used in research, and the validation of diagnoses and treatments in administrative databases is needed. The primary objective of this study was to validate an existing algorithm based on dispensed prescriptions and diagnoses of skin conditions to identify pediatric patients with atopic dermatitis (AD), using a diagnosis of AD in primary care as a gold standard.

METHODS

Retrospective observational data were collected from nation-wide secondary care and pharmacy-dispensed medication databases and two regional primary care databases in Sweden. An existing algorithm and a Modified algorithm, using skin-specific diagnoses from secondary care and/or pharmacy-dispensed prescriptions to identify patients with AD, were assessed. To verify the presence of AD, diagnoses from primary care were used in the base case and complemented with diagnoses from secondary care in a sensitivity analysis.

RESULTS

The sensitivity (30.0%) and positive predictive value (PPV) (40.7%) of the existing algorithm were low in the pediatric patient population when using primary care data only but increased when secondary care visits were also included in the Modified algorithm (sensitivity, 62.1%; PPV, 66.3%). The specificity of the two algorithms was high in both the base case and sensitivity analysis (95.1% and 94.1%). In the adult population, sensitivity and PPV were 20.4% and 8.7%, respectively, and increased to 48.3% and 16.9% when secondary care visits were also included in the Modified algorithm.

CONCLUSION

The Modified algorithm can be used to identify pediatric AD populations using primary and secondary administrative data with acceptable sensitivity and specificity, but further modifications are needed to accurately identify adult patients with AD.

Seasonal and gender variation in skin disease: A cross-sectional study of 3120 patients at Razi hospital

Objective: We aimed to determine the prevalence of different skin diseases and their seasonal variations at the Razi dermatology hospital from 2019 to 2020.

Methods: In this cross-sectional study, we obtained data from the medical records of 3120 patients visiting the dermatology clinic of Razi hospital. The prevalence of skin diseases was evaluated using meteorologically defined seasons. We looked for significant equally distributed results during each season.

Results: During all seasons, women were referred to our clinic more frequently than men. Some diseases demonstrated significant seasonality with a peak during the winter, including acne, eczema, wart, seborrheic dermatitis, nevus, vitiligo, lentigo, and dermatophytosis. Atopic dermatitis was more frequent during the spring and winter compared with other seasons (p < .05). Actinic keratosis and lichen planus showed a significant seasonal trend with a peak during the summer (p < .05). Infections, including viral, bacterial, and fungal skin diseases, were more frequent during the winter than the summer (p = .001).

Conclusion: This study provides an overview of the seasonal distribution of dermatology visits at our referral hospital, which will aid in developing better policies to prevent and manage skin disorders in outpatient visits.

Diverging trends of respiratory allergies and eczema in Greek schoolchildren: Six surveys during 1991-2018

Background: The prevalence of childhood asthma, rhinoconjunctivitis, and eczema in the city of Patras, Greece, has been followed in four consecutive surveys since 1991. After a continuous rise in the prevalence of all three of these disorders, a plateau was reached for asthma between 2003 and 2008, whereas the prevalence of rhinoconjunctivitis and eczema continued to increase. Objective: To investigate these trends in the same population into the following decade. Methods: We repeated two methodologically identical cross-sectional parental questionnaire surveys in 2013 and 2018 among 8-9-year-old schoolchildren (N = 2554 and N = 2648, respectively). In 2018, spirometry and fractional exhaled nitric oxide (FeNO) measurements were also performed. Results: Current asthma (i.e., wheeze/asthma in the past 2 years) decreased from 6.9% in 2008 to 5.2% in 2013 and 4.3% in 2018 (p for trend < 0.001). The prevalence of lifetime ("ever had") rhinoconjunctivitis also declined (5.1% in 2008, 4.4% in 2013, 3.0% in 2018; p for trend < 0.001), whereas that of lifetime eczema increased (10.8%, 13.6%, and 16.1%, respectively; p for trend < 0.001). The relative risk of current asthma in children with ever-had rhinoconjundtivitis was 7.73 in 2008, 6.00 in 2013, and 6.69 in 2018, whereas the relative risk in those with ever-had eczema was 5.15, 2.80, and 2.22, respectively. Among children with asthma, those with rhinoconjunctivitis had lower forced expiratory volume in the first second of expiration and higher FeNO values than those with eczema. Conclusion: The prevalence of asthma and rhinoconjunctivitis declined during the past decade in Greek schoolchildren, whereas the prevalence of eczema continued to rise. Nevertheless, the relationship between rhinoconjunctivitis and asthma remained strong, whereas the association between eczema and asthma appears to have weakened.

Early-Life Adversity Due to Bereavement and Inflammatory Diseases in the Next Generation: A Population Study in Transgenerational Stress Exposure

Emerging evidence suggests that trauma experienced in childhood has negative transgenerational implications for offspring mental and physical health. We aimed to investigate whether early-life adversity experienced as bereavement is associated with chronic inflammatory health in offspring. The study population included 3 generations of Swedish families with a base population of 453,516 children (generation 3) born in 2001–2012. Exposure was defined as the middle generation’s (generation 2) experiencing bereavement in childhood due to the death of a parent (generation 1). Outcomes in generation 3 included 2 diagnoses of inflammatory diseases, including asthma, allergic diseases, eczema, and autoimmune diseases. Survival analysis was used to identify causal pathways, including investigation of mediation by generation 2 mood disorders and socioeconomic status (SES). We found that early-life bereavement experienced by women was associated with early-onset offspring asthma (hazard ratio = 1.15, 95% confidence interval: 1.08, 1.23); mediation analysis revealed that 28%–33% of the association may be mediated by SES and 9%–20% by mood disorders. Early-life bereavement experienced by men was associated with autoimmune diseases in offspring (hazard ratio = 1.31, 95% confidence interval: 1.06, 1.62), with no evidence of mediation. In conclusion, adversity experienced early in life may contribute to an increased risk of inflammatory diseases which is partly mediated by mood disorders and SES.

The association of asthma, atopic dermatitis, and allergic rhinitis with peripartum mental disorders

BACKGROUND

Atopic diseases are characterized by dysregulated inflammatory response, which may incur the onset of peripartum mental disorders, but the impact remains unknown. This study examined whether and to what extent the history of atopic diseases is associated with newly onset peripartum mental disorders.

METHODS

Using population-based registries, we identified all primiparous women who gave birth to live singletons in Denmark during 1978-2016 (n = 937,422). The exposure was hospital contact due to the three major types of atopic diseases-asthma, atopic dermatitis, and allergic rhinitis-before conception. The primary outcome was any hospital contact for mental disorder during pregnancy and 1-year postpartum, which was further classified into affective disorders, neurotic, stress-related and somatoform disorders, and substance abuse. The follow-up started from the date of conception and ended at the date of the first diagnosis of mental disorders, 1-year postpartum, death, emigration, or December 31, 2016, whichever came first. Cox regression was used, adjusted for calendar year, age at childbirth, education, residence, and Charlson comorbidity index.

RESULTS

A total of 24,016 (2.6%) women received diagnosis of at least one of the three atopic diseases before conception (asthma, 1.7%; atopic dermatitis, 0.6%; and allergic rhinitis, 0.8%). Exposure to asthma, atopic dermatitis, or allergic rhinitis was associated with a 37% increased overall risk of peripartum mental disorders (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.27-1.49). Higher risks were observed among women with more frequent hospital contacts for atopic disease (HR, 1.80; 95% CI, 1.37-2.35; ≥5 times), and with recent hospital contacts for atopic disease (HR, 1.74; 95% CI, 1.48-2.06; within 2 years before conception). Specific associations were observed between asthma and neurotic, stress-related and somatoform disorders (HR, 1.40; 95% CI, 1.21-1.62), and between atopic dermatitis and substance abuse (HR, 1.62; 95% CI, 1.12-2.34).

CONCLUSIONS

History of asthma, atopic dermatitis, and allergic rhinitis before conception was associated with increased risks of peripartum mental disorders. Women who have atopic diseases before pregnancy may benefit from systematic mental health monitoring.

BCG Vaccination in Early Childhood and Risk of Atopic Disease: A Systematic Review and Meta-Analysis

Background

Several large-scale studies suggest that Bacille Calmette–Guerin (BCG) vaccination in early childhood may reduce the risk of atopic diseases, but the findings remain controversial. Here, we aimed to investigate the potential correlation between early childhood BCG vaccination and the risk of developing atopic diseases.

Methods

Eligible studies published on PubMed, EMBASE, and Cochrane CENTRAL were systematically sourced from 1950 to July 2021. Studies with over 100 participants and focusing on the association between BCG vaccine and atopic diseases including eczema, asthma, and rhinitis were included. Preliminary assessment of methods, interventions, outcomes, and study quality was performed by two independent investigators. Odds ratio (OR) with 95% confidence interval (CI) was calculated. Random effects of the meta-analysis were performed to define pooled estimates of the effects.

Results

Twenty studies with a total of 222,928 participants were selected. The quantitative analysis revealed that administering BCG vaccine in early childhood reduced the risk of developing asthma significantly (OR 0.77, 95% CI 0.63 to 0.93), indicating a protective efficacy of 23% against asthma development among vaccinated children. However, early administration of BCG vaccine did not significantly reduce the risk of developing eczema (OR 0.94, 95% CI 0.76 to 1.16) and rhinitis (OR 0.99, 95% CI 0.81 to 1.21). Further analysis revealed that the effect of BCG vaccination on asthma prevalence was significant especially in developed countries (OR 0.73, 95% CI 0.58 to 0.92).

Conclusion

BCG vaccination in early childhood is associated with reduced risk of atopic disease, especially in developed countries.

Pediatric asthma incidence rates in the United States from 1980 to 2017

BACKGROUND

Few studies have examined longitudinal asthma incidence rates (IRs) from a public health surveillance perspective.

OBJECTIVE

Our aim was to calculate descriptive asthma IRs in children over time with consideration for demographics and parental asthma history.

METHODS

Data from 9 US birth cohorts were pooled into 1 population covering the period from 1980 to 2017. The outcome was earliest parental report of a doctor diagnosis of asthma. IRs per 1,000 person-years were calculated.

RESULTS

The racial/ethnic backgrounds of the 6,283 children studied were as follows: 55% European American (EA), 25.5% African American (AA), 9.5% Mexican-Hispanic American (MA) and 8.5% Caribbean-Hispanic American (CA). The average follow-up was 10.4 years (SD = 8.5 years; median = 8.4 years), totaling 65,291 person-years, with 1789 asthma diagnoses yielding a crude IR of 27.5 per 1,000 person-years (95% CI = 26.3-28.8). Age-specific rates were highest among children aged 0 to 4 years, notably from 1995 to 1999, with a decline in EA and MA children in 2000 to 2004 followed by a decline in AA and CA children in 2010 to 2014. Parental asthma history was associated with statistically significantly increased rates. IRs were similar and higher in AA and CA children versus lower but similar in EA and MA children. The differential rates by sex from birth through adolescence principally resulted from a decline in rates among males but relatively stable rates among females.

CONCLUSIONS

US childhood asthma IRs varied dramatically by age, sex, parental asthma history, race/ethnicity, and calendar year. Higher rates in the 0- to 4-year-olds group, particularly among AA/CA males with a parental history of asthma, as well as changes in rates over time and by demographic factors, suggest that asthma is driven by complex interactions between genetic susceptibility and variation in time-dependent environmental and social factors.

Nationwide paediatric cohort study of a protective association between allergy and complicated appendicitis

BACKGROUND

In a nationwide cohort the potentially protective association between allergy and complicated appendicitis was analysed, and the influence of seasonal antigens, antihistamine treatment, and timing of allergy onset assessed.

METHODS

Some 1 112 571 children born between 2000 and 2010 were followed from birth until the end of 2014. A cross-sectional analysis of appendicitis cases, with comparison of allergic versus non-allergic children for absolute risk and odds of complicated appendicitis was first undertaken. This was followed by a longitudinal analysis of children with allergy and matched controls who had never had an allergy, for incidence rate and hazard of subsequent complicated or simple appendicitis.

RESULTS

Of all children, 20.4 per cent developed allergy and 0.6 per cent had appendicitis during follow-up. Among children with appendicitis, complicated appendicitis was more common among non-allergic children (18.9 per cent, 948 of 5016) than allergic children (12.8 per cent, 173 of 1351) (P < 0.001), and allergic children had a lower adjusted odds of complicated appendicitis (adjusted odds ratio (OR) 0.80, 95 per cent c.i. 0.67 to 0.96; P = 0.021). The risk of complicated appendicitis among children with manifest allergy was reduced by one-third in the longitudinal analysis (incidence rate 0.13 versus 0.20 per 1000 person-years; hazard ratio (HR) 0.68, 95 per cent c.i. 0.58 to 0.81; P < 0.001), whereas the risk of simple appendicitis remained unchanged (incidence rate 0.91 versus 0.91; HR 1.00, 0.94 to 1.07; P = 0.932). Seasonal antigen exposure was a protective factor (adjusted OR 0.82, 0.71 to 0.94; P = 0.004) and ongoing antihistamine medication a risk factor (adjusted OR 2.28, 1.21 to 4.28; P = 0.012).

CONCLUSION

Children with allergy have a lower risk of complicated appendicitis, but the same overall risk of simple appendicitis. Seasonal antigen exposure reduced, and antihistamine treatment increased, the risk of complicated disease.

Pre-eclampsia and risk of early-childhood asthma: a register study with sibling comparison and an exploration of intermediate variables

BACKGROUND

We aimed to study whether pre-eclampsia is associated with childhood asthma, allergic and non-allergic asthma, accounting for family factors and intermediate variables.

METHODS

The study population comprised 779 711 children born in 2005-2012, identified from Swedish national health registers (n = 14 823/7410 exposed to mild/moderate and severe pre-eclampsia, respectively). We used Cox regression to estimate the associations of mild/moderate and severe pre-eclampsia with incident asthma, before and after age 2 years. Cox regressions were controlled for familial factors using sibling comparisons, then stratified on high and low risk for intermediate variables: caesarean section, prematurity and small for gestational age. We used logistic regression for allergic and non-allergic prevalent asthma at 6 years as a measure of more established asthma.

RESULTS

The incidence of asthma in children was 7.7% (n = 60 239). The associations varied from adjusted hazard ratio (adjHR) 1.11, 95% confidence interval (CI): 1.00, 1.24 for mild/moderate pre-eclampsia and asthma at >2 years age, to adjHR 1.78, 95% CI: 1.64, 1.95 for severe pre-eclampsia and asthma at <2 years age. Sibling comparisons attenuated most estimates except for the association between severe pre-eclampsia and asthma at <2 years age (adjHR 1.45, 95% CI: 1.10, 1.90), which also remained when stratifying for the risk of intermediates. Mild/moderate and severe pre-eclampsia were associated with prevalent non-allergic (but not allergic) asthma at 6 years, with adjusted odds ratio (adjOR) 1.17, 95% CI: 1.00, 1.36 and adjOR 1.51, 95% CI: 1.23, 1.84, respectively.

CONCLUSIONS

We found evidence that severe, but not mild/moderate, pre-eclampsia is associated with asthma regardless of familial factors and confounders.

The Epidemiology and Global Burden of Atopic Dermatitis: A Narrative Review

The global epidemiology of atopic dermatitis (AD) in the current decade (2009-2019) has not been extensively reported. Epidemiological studies play an important role in presenting the risk factors of AD, as detailed prevalence and incidence data could demonstrate the burden of disease in the population of adults, adolescents, and children in different geographical regions. Thus, the primary objective of this review was to assess and summarize the epidemiological studies of the prevalence and incidence of AD in different age groups, focusing on data from studies published for 2009 to 2019. After a thorough literature search, six countries were identified from African, Asian, and European regions respectively, who published studies on AD. In contrast, only two studies were identified from Australia and New Zealand, three countries from North America and two from South America published AD studies, respectively. The highest prevalence of AD from included studies was noted among Swedish children with 34%, while the lowest prevalence was in Tunisian children with 0.65%; studies reporting incidence data were far less numerous. A common trend in the prevalence of AD was that children would have a higher prevalence as compared to adolescents and adults. The severity and morbidity of the disease showed variance with age, sex, socioeconomic characteristics, geographical location, and ethnicity. Environmental factors played an important role as causative agents in AD. The risk factors that were proven to cause and induce AD were skin barrier impairments due to FLG mutation, changes in the environment, and diet. FLG mutation may impair the skin barrier function by disruption of pH and hydration maintenance of the skin. Lastly, there were only a few studies on the incidence of AD in the 21st century. Therefore, epidemiological studies on childhood and adulthood AD in different continents are still needed, especially on the incidence of AD during adulthood.

Association of Childhood Atopic Dermatitis With a Higher Risk of Health Care Utilization and Drug Use for Asthma: A Nationwide Cohort Study

BACKGROUND

Overwhelming evidence supports a causal relationship between occurrence of asthma and atopic dermatitis (AD).

OBJECTIVE

The aims of the study were to determine the incidence of asthma in children with AD and to examine the health care utilization and drug use for asthma in children with AD.

METHODS

Children with hospital-diagnosed AD (cases) were matched with individuals from the background population (controls) in a 1:4 ratio.

RESULTS

In the final cohort (18,625 cases and 74,500 controls), the incident cases of asthma were 4203 among AD cases and 5298 in controls, corresponding to incidence rates of 34 and 9 in cases and controls per 1000 person-years, respectively (hazard ratio [HR] = 3.82, 95% confidence interval [CI] = 3.65-4.00). During the 1-year follow-up period from asthma diagnosis, children with concomitant AD had a significantly higher risk of hospital admission (HR = 1.97, 95% CI = 1.63-2.37), emergency department visits (HR = 1.62, 95% CI = 1.22-2.14), outpatient visits (HR = 1.97, 95% CI = 1.74-2.23), asthma medication (HR = 1.31, 95% CI = 1.27-1.35), and rescue course corticosteroids (HR = 1.74, 95% CI = 1.13-2.69) compared with children with asthma only.

CONCLUSIONS

The risk of being diagnosed with asthma was higher in children with AD. Risk of health care utilization and drug use for asthma was higher in children with both AD and asthma compared with asthma only.

Atopic diseases of the parents predict the offspring's atopic sensitization and food allergy

BACKGROUND

In genetic studies and selected study populations, parental atopy has been associated with atopic diseases in offspring. Our aim was to identify the association between parental atopic diseases and the offspring's atopic sensitization and food allergies, and their effect modifications due to the offspring's sex.

METHODS

The study population (N = 5564) (born between 2001 and 2006) was identified from the population register and live in the province of South Karelia, Finland. Questionnaire-based information on parental atopic diseases was available for 3592 children. The results of skin prick tests, specific IgE tests, and open food challenges (OFC) were collected from patient records.

RESULTS

By 12 years of age, the cumulative incidence of sensitization to food (14% vs 7%, hazard ratio 2.13; 95% CI 1.68-2.69), animal (10% vs 6%, 1.86; 1.42-2.44), and pollen allergens (12% vs 6%, 2.43; 1.85-3.19), as well as food allergies (positive OFC, 5% vs 2%, 2.28; 1.57-3.33), was higher in the offspring of parents with atopic diseases. The cumulative incidence for pollen sensitization was twofold higher for the female offspring of parents with atopic diseases than those of parents without, while it was almost threefold higher among males. The association between parental pollen allergy and the offspring's pollen sensitization was modified by sex according to additive scale estimates (RERI 1.03; 95% CI 0.13-1.91).

CONCLUSION

Until adolescence, parental atopic diseases have a relatively strong association with the offspring's, particularly male offspring's, atopic sensitization, and food allergies. A pronounced association was found between parental pollen allergy and the male offspring's pollen sensitization.

Associations between maternal and environmental exposures on atopic disease in the offspring of mothers with asthma

Background and Objective

Available data on the impact of perinatal and environmental factors on atopic diseases in the offspring are sparse and conflicting. We, therefore, investigated the impact of these factors on the risk of atopic diseases in the offspring of women with asthma.

Methods

Pregnant women referred to give birth at Copenhagen University Hospital‐Hvidovre, Denmark, have since 2007 been invited to participate in the Management of Asthma during Pregnancy program. Women with diagnosed asthma, currently prescribed asthma medication, first visit to the respiratory out‐patient clinic within the first 18 weeks of pregnancy that completed an online questionnaire about atopic diseases in their child were included in the current study.

Results

Five hundred and seventy‐one pregnancies were included. Among the off‐spring, 113 children (21%) had doctor‐diagnosed asthma, 178 (31%) atopic dermatitis (AD), and 55 (32%) both AD and doctor‐diagnosed asthma. AD in the offspring was associated with having a dog at home (odds ratio [OR], 2.56; 95% confidence interval [CI], [1.40–4.67], p = .002), whereas having a cat at home was associated with a higher risk of asthma in the offspring (OR, 2.16; 95% CI, [1.14–4.11], p = .02). The associations remained significant after adjusting for maternal age, smoking status, allergy, treatment with inhaled corticosteroids, forced expiratory volume in 1 s less than 80% predicted, uncontrolled asthma, and history of pre‐pregnancy asthma exacerbations. No association was found between gestational weight gain (GWG) in first trimester and total GWG and atopic disease in the offspring.

Conclusion

Having pets at home is associated with AD and asthma in the offspring of mothers with asthma.

Estimating the prevalence and incidence of treated type 2 diabetes using prescription data as a proxy: A stepwise approach on Iranian data

AIMS

Type 2 diabetes is a serious health challenge, and large-scale studies on its prevalence in Iran are lacking. In pharmacoepidemiology, case-finding can be done by reviewing the prescription databases for specific drug(s) prescribed for a disease. We aimed to determine the prevalence and incidence of type 2 diabetes in Fars province, Iran, using prescription data and a stepwise approach to ascertain the results.

METHODS

A dataset of 3,113 insured individuals aged ≥35 years were selected. Their Prescription Data Centre records were reviewed for all drugs frequently used in controlling type 2 diabetes available in the Iranian pharmacopeia. Then we used a stepwise method for case-finding. In step one, each individual with a positive drug history for type 2 diabetes was labeled as an individual with diabetes. The next two steps were implemented for ascertainment of step one estimations.

RESULTS

Prevalence of type 2 diabetes based on prescription, internist opinion, and phone call verification in 2015 and 2016 was 9.3% and 10.3%, 8.5% and 9.8%, and 7.2% and 8.7%, respectively. An incidence of 1.9% was determined for 2016.

CONCLUSIONS

We obtained a realistic estimation of prevalence and incidence of treated type 2 diabetes, using prescription data which are large-scale, low cost, and real-time.

Childhood atopic dermatitis is associated with a decreased chance of completing education later in life: a register-based cohort study

BACKGROUND

Atopic dermatitis (AD) has far-reaching consequences in childhood and later in working life, but information on how it affects completion of education is sparse.

OBJECTIVES

To compare the educational achievement of individuals with AD in childhood/adolescence and individuals without a history of AD.

METHODS

The study population included patients diagnosed with AD prior to the age of 16 registered in the Danish National Patient Register (DNPR) born in the period 1977-1993 and a 23-fold matched control group from the background population. Cross-linkage of five different Danish registers from 1977 to 2015 allowed comparison of AD patients with controls regarding completion of education.

RESULTS

In total, 10 173 individuals were registered with AD in the DNPR, while 234 683 individuals served as control group. Mild/moderate AD was associated with a decreased chance of completing basic compulsory education [hazard ratios (HR): 0.92, 95% CI: 0.90-0.95] and further academic education (HR: 0.96, 95% CI: 0.93-0.98). Severe AD was associated with a decreased chance of completing further academic education (HR: 0.86, 95% CI: 0.80-0.92), further vocational education (HR: 0.90, 95% CI: 0.84-0.97) and higher education: master's level (HR: 0.66, 95% CI: 0.53-0.81).

CONCLUSION

Atopic dermatitis in childhood/adolescence is associated with a decreased chance of completing an education.

Association of Early Life Exposure to Antibiotics With Risk of Atopic Dermatitis in Sweden

IMPORTANCE

Atopic dermatitis is associated with substantial morbidity in childhood. Further understanding of the underlying factors contributing to its onset is needed.

OBJECTIVE

To assess the association of exposure to antibiotics in the prenatal period and early childhood with risk of atopic dermatitis in a nationwide population in Sweden.

DESIGN, SETTING, AND PARTICIPANTS

This Swedish nationwide, register-based, prospective cohort study used data on mother-child pairs from the Swedish Medical Birth Register linked to other national registers for information on health, socioeconomic, and demographic data. Participants were followed up until an atopic dermatitis outcome, emigration, death, or the end of the study on December 31, 2015. Data for all singleton children and discordant siblings born between March 1, 2006, and December 31, 2010, were included. Data were analyzed from June 1, 2020, to October 31, 2020.

EXPOSURES

Maternal exposure to systemic antibiotics during pregnancy as well as the child's exposure to systemic antibiotics during the first year of life, as defined by a dispensed prescription in the Swedish Prescribed Drug Register.

MAIN OUTCOMES AND MEASURES

Time-to-event analyses were used to estimate the risk of outcome using attained age as a time scale. Atopic dermatitis was defined based on diagnoses in the National Patient Register and medication listed in the Swedish Prescribed Drug Register. Sibling-control analysis was performed to account for shared familial factors.

RESULTS

Among the 722 767 singleton children, the mean (SD) age was 5.8 (2.4) years and 351 589 (48.6%) were female. During the follow-up period, 153 407 children (21.2%) were exposed to antibiotics in utero and 172 405 children (23.8%) were exposed during the first year of life. The risk of atopic dermatitis among children exposed to prenatal antibiotics was greater than that among children who were not exposed (adjusted hazard ratio [aHR], 1.10; 95% CI, 1.09-1.12). In the sibling-control analysis, no association was observed (aHR, 0.96; 95% CI; 0.92-1.00). Exposure to antibiotics during the first year of life was associated with a greater risk of atopic dermatitis (aHR, 1.52; 95% CI, 1.50-1.55), with attenuated associations in the sibling-control analysis (aHR, 1.24; 95% CI, 1.20-1.29).

CONCLUSIONS AND RELEVANCE

In this cohort study, exposure to antibiotics in early life was associated with an increased risk of atopic dermatitis in the general Swedish population, but this risk was partially confounded by familial factors. Research on the ways in which antibiotic use and other shared familial factors affect other atopic diseases may be warranted.

Preventive Effect of Allergen Immunotherapy on Asthma and New Sensitizations

Allergen immunotherapy (AIT) is a disease-modifying treatment for some IgE-mediated allergic diseases with the potential to have important preventive effects. Children with allergic rhinitis have a high risk of developing asthma, and treating allergic rhinitis with AIT may interfere with disease progression and prevent onset of asthma. Although the evidence is limited due to relatively few and heterogeneous studies, data nevertheless suggest that AIT has a preventive effect on development of asthma especially in children with rhinitis due to grass pollen allergy. AIT may also affect the development of new sensitizations. Both the degree of sensitization and the specific sensitization pattern may influence future disease severity and development of comorbidities. Hitherto, the indication for AIT for prevention of development of asthma in grass/birch pollen allergic children has been the same as for treatment of allergic rhinitis. Probably, AIT should be applied in the early stage of the allergic disease to have the greatest preventive effect on disease progression. Consequently, in the future, the potential preventive effects should influence the timing of initiating AIT. The window of opportunity to prevent asthma may primarily exist in young children with mild symptoms and a low degree of sensitization.

Circulating proteins associated with allergy development in infants-an exploratory analysis

Background

Protein profiles that can predict allergy development in children are lacking and the ideal sampling age is unknown. By applying an exploratory proteomics approach in the prospective FARMFLORA birth cohort, we sought to identify previously unknown circulating proteins in early life that associate to protection or risk for development of allergy up to 8 years of age.

Methods

We analyzed plasma prepared from umbilical cord blood (n = 38) and blood collected at 1 month (n = 42), 4 months (n = 39), 18 months (n = 42), 36 months (n = 42) and 8 years (n = 44) of age. We profiled 230 proteins with a multiplexed assay and evaluated the global structure of the data with principal component analysis (PCA). Protein profiles informative to allergic disease at 18 months, 36 months and/or 8 years were evaluated using Lasso logistic regression and random forest.

Results

Two clusters emerged in the PCA analysis that separated samples obtained at birth and at 1 month of age from samples obtained later. Differences between the clusters were mostly driven by abundant plasma proteins. For the prediction of allergy, both Lasso logistic regression and random forest were most informative with samples collected at 1 month of age. A Lasso model with 27 proteins together with farm environment differentiated children who remained healthy from those developing allergy. This protein panel was primarily composed of antigen-presenting MHC class I molecules, interleukins and chemokines.

Conclusion

Sampled at one month of age, circulating proteins that reflect processes of the immune system may predict the development of allergic disease later in childhood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12014-021-09318-w.

Identification of cutaneous fungi and mites in adult atopic dermatitis: analysis by targeted 18S rRNA amplicon sequencing

BACKGROUND

Atopic dermatitis (AD) patients have an altered skin bacterial community, with an abundance of Staphylococcus aureus associated with flares, highlighting that microbial organisms may be important for disease exacerbation. Despite strong evidence of association between bacterial skin colonisation and AD, very limited knowledge regarding the eukaryotic microbial community, including fungi and ectoparasites, in AD exists. In this study, we compared the skin and nasal eukaryotic microbial community between adult AD patients (n = 55) and non-AD healthy controls (n = 45) using targeted 18S rRNA amplicon sequencing. Analysis was based on the presence or absence of eukaryotic microorganisms.

RESULTS

The cutaneous composition of the eukaryotic microbial community and the alpha-diversity differed significantly between AD patients and non-AD individuals, with increased species richness on AD skin. Alpha-diversity and beta-diversity were similar on lesional and non-lesional skin of patients. The ectoparasite Demodex folliculorum and the yeast Geotrichum candidum were significantly more prevalent on the skin of AD patients. The prevalence of D. folliculorum on lesional skin was greater among patients recently treated with topical corticosteroid. Malassezia was one of the most frequently detected genera at all sites, with M. globosa and M. restricta being the most prevalent. M. restricta was under represented in the anterior nares of AD patients as compared to the non-AD control population.

CONCLUSION

Significant differences in the eukaryotic microbial communities were found between AD patients and non-AD individuals, with the most striking finding being the significantly overrepresentation of D. folliculorum on AD skin. Whether D. folliculorum can contribute to skin inflammation in AD needs further investigation.

Prevalence of comorbidities in a surgical pectus excavatum population

Background

Pectus excavatum is the most common chest wall deformity and is associated to various connective tissue, cardiopulmonary, and skeletal abnormalities. Several conditions and syndromes have been associated to pectus excavatum, although the overall health implications of the pectus excavatum phenotype are unclear. Therefore, in this study we aimed to examine the health implications of the pectus excavatum phenotype by assessing all comorbidities and previous medical conditions in a cohort of patients undergoing pectus excavatum surgery.

Methods

This single-centre retrospective prevalence study included 1,046 patients undergoing minimal invasive repair of pectus excavatum from 2001 to 2012. Hospital medical charts were assessed and comorbidities and previous medical conditions were registered systematically and categorized according to the affected organ system.

Results

In our study population of 1,046 patients, we registered 623 conditions. The median age was 17 years and the majority of patients (56%) had no previous or present conditions. Notable prevalence of asthma (8.8%), allergies (12.3%), previous hernia surgery (5.2%), and psychiatric conditions (4.9%) were found.

Conclusions

The majority of patients undergoing pectus excavatum surgery have no comorbidities or previous medical conditions. It seems that this patient category is comparable to the background population in this regard and our findings do not support screening this patient category for associated conditions.

Examining the effects of pre-pregnancy weight and gestational weight gain on allergic disease development in offspring: a protocol for a population-based study using health administrative databases in Ontario, Canada

INTRODUCTION

Over the last 20 years, excess maternal pre-pregnancy weight (overweight and obesity) and gestational weight gain have become the most common morbidities in pregnancy. These morbidities may pose a threat to fetal immunological development through associated metabolic dysfunction and inflammation and, as such, may partly explain the concurrent rise of paediatric allergic disease. We will examine the effect of maternal pre-pregnancy weight and gestational weight gain during pregnancy on the incidence of allergic diseases among offspring in Canada's most populous province.

METHODS AND ANALYSIS

We will conduct a retrospective, population-based cohort study of all singleton live births to residents of Ontario, Canada in 2012-2013 and 2013-2014. The study population will be defined using maternal-newborn records from the provincial birth registry, which captures information on maternal pre-pregnancy weight and gestational weight gain. The cohort will be linked with provincial health administrative databases, allowing for follow-up of neonates through early childhood until 2019 (5-7 years of age). Allergic disease development (asthma, rhinitis, atopic dermatitis and anaphylaxis) will be ascertained using diagnostic codes from healthcare encounters. Potential confounders have been identified a priori through a directed acyclic graph. Cox proportional hazards regression models will be employed to assess the associations between maternal pre-pregnancy weight, gestational weight gain and incident paediatric allergic disease. Several preplanned sensitivity analyses will be conducted, including a probabilistic bias analysis of outcome misclassification.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Research Ethics Board of the Children's Hospital of Eastern Ontario and the ICES Privacy Office. Findings will be disseminated in scientific conference presentations and peer-reviewed publications.

Clinical and Economic Burden of Pediatric Mild-to-Moderate Atopic Dermatitis: A Population-Based Nested Case-Control Study in Sweden

Introduction

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition characterized by pruritic, eczematous lesions. Recent evidence suggests that AD may be a systemic disorder, implying that management of this disease extends beyond merely controlling symptoms associated with AD. Even though this disease is highly prevalent in children and patients typically present with mild-to-moderate symptoms, the disease burden is not well established.

Methods

A large, retrospective cohort study of Swedish population data was conducted to compare the clinical burden in terms of healthcare resource use and direct medical costs for pediatric mild-to-moderate (pM2M) AD patients (≤ 14 years of age, N = 87,721) with matched controls. The burden of a severe AD cohort was also evaluated. Severity of AD was defined by treatment usage and systemic treatment was used as a proxy for severe AD. A robust approach was used by including any type of secondary care visits known to be more common in AD patients than in the general population; however, data for primary care visits were not available.

Results

For healthcare resource use, the incidence rate ratio (pM2M AD versus reference cohort) of secondary care visits ranged from 1.56 to 2.35 during each of 5 years after AD onset (all p < 0.001), with largest differences seen in years 1–2. The average direct medical cost (SD) was €1111 (3416) and €524 (2446) in the pM2M AD and reference cohorts, respectively. The corresponding estimate in the severe AD cohort was €1906 (7067). Including all secondary care visits and pharmacy-dispensed medications, the pM2M AD cohort was shown to have an additional €118.9 million in direct medical costs over 5 years compared with the reference cohort.

Conclusions

This study shows significant clinical and economic burden of pM2M AD with important secondary care resource utilization, suggesting a need for further research to increase treatment options and improve the management of these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-020-00470-z.

Relations between vitamin D3, total and specific IgE for house dust mites in atopic dermatitis patients

Atopic dermatitis (AD) is a chronic recurrent inflammatory skin disease. There are a lot of evidences on the importance of vitamin D and house dust mite (HDM) allergens in the etiology and course of AD. The objectives of this study are to evaluate the relation between vitamin D3 level and house dust mites (HDM) Dermatophagoidspecies sensitization in pathogenesis of atopic dermatitis. Cross-sectional design study was conducted on 50 atopic dermatitis patients. Blood analysis were done to determine level of vitamin D3, total IgE by fluorescent immunoassay & specific IgE for HDM (d1, d2) & other inhalant allergens by ELISA test. There was significant high negative correlation with the specific IgE for HDM (r =  −0. 62, p < 0.001) and vitamin D3. & there was non-significant minimal negative correlation with the specific IgE and other inhalant allergens (r = − 0.10, p > 0.05). There was a statistically significant relation between level of vitamin D3 and atopic dermatitis severity and sensitization to HDM and other allergens.

Atopic dermatitis incidence and risk factors in young adults in Castellon (Spain): A prospective cohort study

INTRODUCTION

There are few atopic dermatitis (AD) incidence cohort studies in young adults, the etiology of this disease remains obscure, and AD risk factors in adults are not well understood. The objective of this study was to estimate AD ten-year incidence and prevalence in a cohort of adolescent aged 14-16 at inception in Castellon province in Valencia Region, Spain and describe related risk factors.

MATERIAL AND METHODS

From 2002 to 2012, a population-based prospective cohort study was carried out. Questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC) were used with an additional questionnaire for related factors completed by participants and their parents, respectively, in 2002. In 2012 the same questionnaires were completed by the participants' through a telephone interview, and incidence and prevalence of AD were estimated. Directed acyclic graphs, Poisson regression and inverse probability weighted regression adjustment were used.

RESULTS

The participation rate was 79.5% (1435/1805) with AD lifetime prevalence of 34.9% and AD incidence of 13.5 per 1000 person years. Females presented higher prevalence and incidence than males. After adjustment significant risk factors were being female, history of asthma or allergic rhinitis, family history of AD, history of respiratory infections, history of bronchitis, history of pneumonia, history of sinusitis, and birthplace outside Castellon province. The highest AD population attributable risks were female, 30.3%, and history of respiratory infections 15.3%. Differences with AD childhood risk factors were found.

CONCLUSIONS

AD incidence in our cohort was high and several risks factors were related to AD.

Atopic dermatitis in schoolchildren and adolescents: a critical review of Italian epidemiological data and systemic treatments

INTRODUCTION

The epidemiology of atopic dermatitis (AD) is largely different in pre-school and schoolchildren. We summarized the available epidemiological data on schoolchildren (6-11 years) and adolescents (12-17 years) in Italy and reviewed information on systemic treatments for moderate-to-severe AD in adolescents.

EVIDENCE ACQUISITION

In January 2019, we searched for data on prevalence and/or incidence of AD and on the efficacy, effectiveness and safety of systemic AD therapies. Papers were evaluated and selected, and relevant information was extracted. Twenty papers from 17 studies reported original epidemiological information on AD in Italy.

EVIDENCE SYNTHESIS

Most studies were conducted before 2005. Though variations emerged between studies, the lifetime prevalence of AD was estimated between 15-17% in schoolchildren and between 8-13% in adolescents. The (12-months) period prevalence of AD was estimated between 8-10% in children and between 8-11% in adolescents. Up-to-date information on the prevalence of severe AD is not available. Cyclosporine A may be used in pediatric age patients (children and adolescents) with persistent or severe AD refractory to topical treatments, but its use has several limitations, and is not recommended in patients younger than 16 years. The treatment paradigm of AD is still far from being satisfactory.

CONCLUSIONS

We provided a quantitative synthesis of AD epidemiology in Italian schoolchildren and adolescents. Recent data are needed, as most information dates back to the 1990s or early 2000s, and data on the incidence of AD, the proportion of severe cases, and treatment of severe cases in the real-world setting are scanty.