Different definitions of atopic dermatitis: impact on prevalence estimates and associated risk factors

Identification of eczema clusters and their association with filaggrin and atopic comorbidities: analysis of five birth cohorts

BACKGROUND

Longitudinal modelling of the presence/absence of current eczema through childhood has identified similar phenotypes, but their characteristics often differ between studies.

OBJECTIVES

To demonstrate that a more comprehensive description of longitudinal pattern of symptoms may better describe trajectories than binary information on eczema presence.

METHODS

We derived six multidimensional variables of eczema spells from birth to 18 years of age (including duration, temporal sequencing and the extent of persistence/recurrence). Spells were defined as consecutive observations of eczema separated by no eczema across 5 epochs in five birth cohorts: infancy (first year); early childhood (age 2-3 years); preschool/early school age (4-5 years); middle childhood (8-10 years); adolescence (14-18 years). We applied Partitioning Around Medoids clustering on these variables to derive clusters of the temporal patterns of eczema. We then investigated the stability of the clusters, within-cluster homogeneity and associated risk factors, including FLG mutations.

RESULTS

Analysis of 7464 participants with complete data identified five clusters: (i) no eczema (51.0%); (ii) early transient eczema (21.6%); (iii) late-onset eczema (LOE; 8.1%); (iv) intermittent eczema (INT; 7.5%); and (v) persistent eczema (PE; 11.8%). There was very-high agreement between the assignment of individual children into clusters when using complete or imputed (n = 15 848) data (adjusted Rand index = 0.99; i.e. the clusters were very stable). Within-individual symptom patterns across clusters confirmed within-cluster homogeneity, with consistent patterns of symptoms among participants within each cluster and no overlap between the clusters. Clusters were characterized by differences in associations with risk factors (e.g. parental eczema was associated with all clusters apart from LOE; sensitization to inhalant allergens was associated with all clusters, with the highest risk in the PE cluster). All clusters apart from LOE were associated with FLG mutations. Of note, the strongest association was for PE [relative risk ratio (RRR) 2.70, 95% confidence interval (CI) 2.24-3.26; P < 0.001] followed by INT (RRR 2.29, 95% CI 1.82-2.88; P < 0.001).

CONCLUSIONS

Clustering of multidimensional variables identified stable clusters with different genetic architectures. Using multidimensional variables may capture eczema development and derive stable and internally homogeneous clusters. However, deriving homogeneous symptom clusters does not necessarily mean that these are underpinned by completely unique mechanisms.

Season of birth and atopic dermatitis in early infancy: results from the Japan Environment and Children's Study

BACKGROUND

Atopic dermatitis (AD) is reported to be more prevalent in children who were born in autumn than in spring. Here, we investigated how early the association between season of birth and eczema or AD can be observed in the postnatal period. We also examined whether specific prevalence outcomes for infant eczema and AD differed according to sex and maternal history of allergic disease in a large Japanese cohort.

METHODS

Using data of 81,615 infants from the Japan Environment and Children's Study, we examined the associations of birth month or season with four different outcomes-eczema at 1 month, 6 months, and 1 year of age and physician-diagnosed AD up to 1 year of age-using multiple logistic regression analysis. We also analyzed the effect of maternal history of allergic disease on these outcomes stratified by infant sex.

RESULTS

The risk of eczema at 1 month was highest in infants born in July. In contrast, infants born in autumn had higher risks of eczema at 6 months (adjusted odds ratio [aOR], 2.19; 95% confidence interval [CI], 2.10-2.30) and at 1 year (aOR, 1.08; 95% CI, 1.02-1.14) and of physician-diagnosed AD up to 1 year of age (aOR, 1.33; 95% CI, 1.20-1.47) compared with infants born in spring. Eczema and AD were more prevalent in infants with a maternal history of allergic disease, particularly boys.

CONCLUSIONS

Our findings suggest that the prevalence of AD is associated with the season of observation. Eczema is prevalent in infants born in autumn, and this phenomenon was observed in infants as young as 6 months old. The risk associated with being born in autumn was particularly clear in boys with a maternal history of allergic disease.

TRIAL REGISTRATION

UMIN000030786.

Evolution of Eczema, Wheeze, and Rhinitis from Infancy to Early Adulthood: Four Birth Cohort Studies

Rationale: The relationship between eczema, wheeze or asthma, and rhinitis is complex, and epidemiology and mechanisms of their comorbidities is unclear. Objectives: To investigate within-individual patterns of morbidity of eczema, wheeze, and rhinitis from birth to adolescence/early adulthood. Methods: We investigated onset, progression, and resolution of eczema, wheeze, and rhinitis using descriptive statistics, sequence mining, and latent Markov modeling in four population-based birth cohorts. We used logistic regression to ascertain if early-life eczema or wheeze, or genetic factors (filaggrin [FLG] mutations and 17q21 variants), increase the risk of multimorbidity. Measurements and Main Results: Single conditions, although the most prevalent, were observed significantly less frequently than by chance. There was considerable variation in the timing of onset/remission/persistence/intermittence. Multimorbidity of eczema+wheeze+rhinitis was rare but significantly overrepresented (three to six times more often than by chance). Although infantile eczema was associated with subsequent multimorbidity, most children with eczema (75.4%) did not progress to any multimorbidity pattern. FLG mutations and rs7216389 were not associated with persistence of eczema/wheeze as single conditions, but both increased the risk of multimorbidity (FLG by 2- to 3-fold, rs7216389 risk variant by 1.4- to 1.7-fold). Latent Markov modeling revealed five latent states (no disease/low risk, mainly eczema, mainly wheeze, mainly rhinitis, multimorbidity). The most likely transition to multimorbidity was from eczema state (0.21). However, although this was one of the highest transition probabilities, only one-fifth of those with eczema transitioned to multimorbidity. Conclusions: Atopic diseases fit a multimorbidity framework, with no evidence for sequential atopic march progression. The highest transition to multimorbidity was from eczema, but most children with eczema (more than three-quarters) had no comorbidities.

12-month prevalence of atopic dermatitis in resource-rich countries: a systematic review and meta-analysis

There is a lack of robust prevalence estimates of atopic dermatitis (AD) globally and trends over time due to wide variation of populations and age groups studied, different study methodologies and case definitions used. We sought to characterize 12-month AD prevalence across the life span and change over time in resource-rich countries focusing on population-based studies and using a standardized AD case definition. This systematic review was conducted according to PRISMA guidelines. Medline (Ovid), Embase, WOS core collection, Cinahl, and Popline were searched for studies published since inception through August 15, 2016. Studies were synthesized using random effects meta-analysis. Sources of heterogeneity were investigated using subgroup analyses and meta-regression. From 12,530 records identified, 45 studies met the inclusion criteria. Meta-analysis with random effects revealed the 12-month period prevalence of 9.2% (95% confidence interval 8.4–10.1%). The prevalence was significantly higher among 0–5-year-old children (16.2%; 95% confidence interval 14.2–18.7%) than in older age groups. Studies using a random sampling strategy yielded lower prevalence estimates than studies relying on other sampling methods. There was no clear time trend in AD prevalence over the period of 1992–2013.

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.

Data-driven research on eczema: Systematic characterization of the field and recommendations for the future

Background

The past decade has seen a substantial rise in the employment of modern data-driven methods to study atopic dermatitis (AD)/eczema. The objective of this study is to summarise the past and future of data-driven AD research, and identify areas in the field that would benefit from the application of these methods.

Methods

We retrieved the publications that applied multivariate statistics (MS), artificial intelligence (AI, including machine learning-ML), and Bayesian statistics (BS) to AD and eczema research from the SCOPUS database over the last 50 years. We conducted a bibliometric analysis to highlight the publication trends and conceptual knowledge structure of the field, and applied topic modelling to retrieve the key topics in the literature.

Results

Five key themes of data-driven research on AD and eczema were identified: (1) allergic co-morbidities, (2) image analysis and classification, (3) disaggregation, (4) quality of life and treatment response, and (5) risk factors and prevalence. ML&AI methods mapped to studies investigating quality of life, prevalence, risk factors, allergic co-morbidities and disaggregation of AD/eczema, but seldom in studies of therapies. MS was employed evenly between the topics, particularly in studies on risk factors and prevalence. BS was focused on three key topics: treatment, risk factors and allergy. The use of AD or eczema terms was not uniform, with studies applying ML&AI methods using the term eczema more often. Within MS, papers using cluster and factor analysis were often only identified with the term AD. In contrast, those using logistic regression and latent class/transition models were "eczema" papers.

Conclusions

Research areas that could benefit from the application of data-driven methods include the study of the pathogenesis of the condition and related risk factors, its disaggregation into validated subtypes, and personalised severity management and prognosis. We highlight BS as a new and promising approach in AD and eczema research.

Prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age: a systematic review and meta-analysis

This study aims to quantify the difference in prevalence of eczema between cesarean-born and vaginal-born infants within 1 year of age through a systematic review and meta-analysis. Six electronic databases were searched from inception to August 31, 2021. Studies were included if they reported the prevalence of eczema in infants within 1 year of age with specified mode of delivery. The quality of included studies was assessed using the Joanna Briggs Instrument Critical Appraisal Checklist. Pooled prevalence and odds ratio (OR) were estimated by meta-analyses of included studies. Meta-regression was conducted to explore factors affecting heterogeneity of the prevalence of eczema. Nine studies were included with 3,758 cesarean-born infants and 9,631 vaginal-born infants. The prevalence of eczema in cesarean-born infants [27.8%; 95% confidence interval (CI): 17.7-39.2] was higher than in vaginal-born infants (20.1%; 95% CI: 13.9-28.1), with a pooled OR of 1.31 (95% CI: 1.04-1.65). Subgroup analyses showed that the prevalence of eczema in cesarean-born infants varied according to country, study design, and method of ascertainment. Additionally, the pooled prevalence of eczema in vaginal-born infants differed by age at which eczema was identified. Meta-regression analysis showed that study design and eczema ascertainment method were significant sources of heterogeneity.

CONCLUSION

About 28% of cesarean-born infants within 1 year of age developed eczema, significantly higher than the 20% rate or occurrence seen in vaginal-born infants.

PROTOCOL REGISTRATION

CRD 42,020,152,437.

WHAT IS KNOWN

• Eczema, a complex inflammatory cutaneous disorder characterized by immune mediated inflammation and epidermal barrier dysfunction, is one of the most common allergic disorders in infants. • Eczema may increase the risk of immune-mediated inflammatory disease such as food allergy, asthma, and allergic rhinitis, leading to psychological and social burdens on affected individuals and their families. • Mode of delivery may be associated with the risk of developing eczema, although further studies are needed to clarify such differences.

WHAT IS NEW

• This is the first systematic review designed to estimate the prevalence of eczema in cesarean- and vaginal-born infants within 1 year of age. • Cesarean delivery may increase the risk of developing eczema in infants within the first year of life.

Annoying Psoriasis and Atopic Dermatitis: A Narrative Review

Skin is an important organ that mainly functions as a barrier. Skin diseases can damage a person's self-confidence and reduce their willingness to socialize, as well as their social behavior and willingness. When the skin appearance is abnormal, in addition to affecting the quality of life, it often leads to personal, social, and psychological dysfunction and even induces depression. Psoriasis and atopic dermatitis are common chronic skin diseases. Their prevalence in the world is 3-10%, and there is an increasing trend year by year. These congenital or acquired factors cause the dysfunction of the immune system and then destroy the barrier function of the skin. Because these patients are flooded with a variety of inflammatory mediators, this causes skin cells to be in chronic inflammation. Therefore, psoriasis and atopic dermatitis are also considered systemic chronic inflammatory diseases. In the healthcare systems of developed countries, it is unavoidable to spend high costs to relieve symptoms of psoriasis and atopic dermatitis patients, because psoriasis and atopic dermatitis have a great influence on individuals and society. Giving a lot of attention and developing effective treatment methods are the topics that the medical community must work on together. Therefore, we used a narrative review manuscript to discuss pathogenesis, clinical classification, incidence, and treatment options, including topical medication, systemic therapeutics, immunosuppressive medication for psoriasis, and atopic dermatitis, as well as also comparing the differences between these two diseases. We look forward to providing readers with comprehensive information on psoriasis and atopic dermatitis through this review article.

Modelling trajectories of parentally reported and physician-confirmed atopic dermatitis in a birth cohort study

BACKGROUND

In a population-based birth cohort, we aimed to identify longitudinal trajectories of atopic dermatitis (AD) during childhood using data from different sources (validated questionnaires and healthcare records). We investigated the impact of different AD definitions on such trajectories and their relationships with various risk factors.

METHODS

Of the 1184 children born into the study, 1083 had information on current AD for at least three follow-ups from birth to age 11 years and were included in the analysis for parentally reported AD (PRAD). Data were transcribed from healthcare records for 916 of 1184 children for the analysis of doctor-diagnosed AD (DDAD). We also derived a composite definition of AD (CDAD) (at least two of the following: PRAD, DDAD, current use of AD treatment). Using latent class analysis (LCA), we determined longitudinal profiles of AD using the three definitions. Filaggrin (FLG) genotype data were available for 803 white participants.

RESULTS

For PRAD, LCA identified four AD classes ('no AD', 'persistent', 'early-onset remitting' and 'late-onset'). For DDAD and CDAD, the optimal number of phenotypes was three ('no AD', 'persistent' and 'early-onset remitting'). Although AD classes at population level appeared similar in different models, a considerable proportion of children (n = 485, 45%) moved between classes. The association with FLG genotype, atopic diseases and early-life risk factors was inconsistent across different definitions, but the association with oral food challenge-confirmed peanut allergy was similar, with a nine- to 11-fold increase among children in the persistent AD class. In a CDAD model, compared with the early-onset remitting class, those with persistent AD were significantly more likely to have (at age 3 years) moderate/severe AD, polysensitization and current wheeze, and were less likely to have been breastfed.

CONCLUSIONS

Standardized composite definitions of AD may help to define AD cases with more precision and identify more consistent long-term trajectories.

Good practice intervention for clinical assessment and diagnosis of atopic dermatitis: Findings from the atopic dermatitis quality of care initiative

Atopic dermatitis (AD) is frequently misdiagnosed and undertreated, resulting in increased morbidity. In 2019, the Atopic Dermatitis Quality of Care Initiative was launched globally to investigate barriers to AD care and note good practice interventions to improve care. The initiative included a literature review to define the challenges in AD and a survey of 32 AD centers to define good practice interventions. One topic studied was best practices for clinical assessment and diagnosis. The literature review revealed the primary gaps included difficulty differentiating AD from other skin disorders, diagnosing atypical AD, staging AD severity in individual patients, and delays in assessment and treatment due to referral time lag. The best clinical practices used by leading AD centers included the use of validated diagnostic criteria, established AD scoring tools including patient-reported outcome measures and electronic health records (EHR), the formation of multidisciplinary teams (MDTs), and improved communication between health care providers (HCPs) and patients. Most centers worked with patient advocacy groups and implemented educational programs for HCPs. AD centers are overcoming issues in AD care. Educating health care providers and the public, using screening surveys, using established guidelines, and communicating with MCTs and patients through EHRs are the most frequently used strategies.

Evaluation of the effect of the interleukin-25 serum concentration on the intensity of the symptoms of atopic dermatitis and epidermal barrier

Introduction

Interleukin 25 (IL-25) is a cytokine with proinflammatory and anti-inflammatory effects, and its biological function of reciprocal epidermal hyperplasia and of inhibiting the filaggrin synthesis points to an essential role connecting the inflammatory process with damage to the epidermal barrier in the course of atopic dermatitis (AD).

Aim

To assess the IL-25 in serum concentration in AD patients and to analyse its possible correlation with the disease intensity and selected epidermal barrier parameters such as transepidermal water loss (TEWL).

Material and methods

The study involved 43 patients with AD and 22 healthy volunteers. The IL-25 concentration was measured using the ELISA method. The intensity of disease symptoms was investigated using W-AZS and EASI indicators. The epidermal barrier was evaluated using a Tewameter TM300 and Corneometer CM825.

Results

The concentration of IL-25 in serum was higher in the study group than in the control group. IL-25 serum concentration correlates with W-AZS/EASI in patients with a severe and moderate course of AD. The concentration of IL-25 affects the TEWL within the affected, evaluated skin surface.

Conclusions

An elevated IL-25 concentration in serum is characteristic for patients with moderate and severe AD intensity. The IL-25 concentration in serum correlates with TEWL and with the moisture level in the affected area. However, further studies are necessary to determine the role played by IL-25 in the course of the disease and how it affects the functional parameters of the epidermal barrier.

Genetics of Asthma and Allergic Diseases

Asthma genes have been identified through a range of approaches, from candidate gene association studies and family-based genome-wide linkage analyses to genome-wide association studies (GWAS). The first GWAS of asthma, reported in 2007, identified multiple markers on chromosome 17q21 as associates of the childhood-onset asthma. This remains the best replicated asthma locus to date. However, notwithstanding undeniable successes, genetic studies have produced relatively heterogeneous results with limited replication, and despite considerable promise, genetics of asthma and allergy has, so far, had limited impact on patient care, our understanding of disease mechanisms, and development of novel therapeutic targets. The paucity of precise replication in genetic studies of asthma is partly explained by the existence of numerous gene-environment interactions. Another important issue which is often overlooked is that of time of the assessment of the primary outcome(s) and the relevant environmental exposures. Most large GWASs use the broadest possible definition of asthma to increase the sample size, but the unwanted consequence of this is increased phenotypic heterogeneity, which dilutes effect sizes. One way of addressing this is to precisely define disease subtypes (e.g. by applying novel mathematical approaches to rich phenotypic data) and use these latent subtypes in genetic studies.

A Qualitative Analysis of Provider Notes of Atopic Dermatitis-Related Visits Using Natural Language Processing Methods

Introduction

Real-world disease management of atopic dermatitis (AD) is hampered by a lack of consistency between providers that treat AD regarding assessment of severity, disease activity, and quality of life. Variability and inconsistency in documentation makes it difficult to understand the impact of AD. This study summarizes AD-related symptoms and concerns captured in unstructured qualitative provider notes by healthcare providers during visits with patients with AD.

Methods

Provider notes were obtained for patients with AD (n = 133,025) from a USA-based ambulatory electronic health records system. The sample included both children (n = 69,551) and adults at least 18 years of age (n = 63,474) receiving treatment from a variety of specialties including primary care, dermatology, and allergy/immunology. Key skin-related words were identified from a review of a sample of notes and natural language processing (NLP) was applied to determine the frequency of the keywords and bigram patterns.

Results

Provider notes largely focused on symptoms (primarily itch) and symptom relief rather than the impact of AD on work or lifestyle. Despite the known relationship between itch and skin pain, neuralgia was not widely documented. Compared to primary care providers, dermatologists’ and allergist/immunologists’ notes had more documentation of symptom-related issues. Personal and work/life burden issues were not widely documented regardless of specialty.

Conclusion

The topics documented in case notes by healthcare providers about their patients with AD focus largely on symptoms and, to a lesser extent, treatment, but do not reflect the burden of AD on patients’ lives. This finding highlights a potential care gap that warrants further investigation.

Nomenclature and clinical phenotypes of atopic dermatitis

Atopic dermatitis is a heterogeneous disease and resists classification. In this review, we discuss atopic dermatitis nomenclature and identify morphologic phenotypes, which will facilitate correct diagnoses and development of treatment strategies. We support using the term 'atopic dermatitis' rather than eczema, because it describes the allergic background and inflammation ('itis') as drivers of the disease. Atopic dermatitis has many morphologic manifestations that vary by topographic area affected, age, or race and require consideration in differential diagnosis. Different phenotypes based on morphology and topographic location, ethnicity, and age are discussed. A better-defined phenotype identification for atopic dermatitis will facilitate earlier and correct diagnosis of this complex condition and inform selection of the most appropriate treatment choice in an era in which targeted therapies may generate more individualized patient care.

Epicutaneous sensitization in the development of food allergy: What is the evidence and how can this be prevented?

There is increasing evidence regarding the importance of allergic sensitization through the skin. In this review, we provide an overview of the atopic march and immune mechanism underlying the sensitization and effector phase of food allergy. We present experimental models and human data that support the concept of epicutaneous sensitization and how this forms one half of the dual-allergen exposure hypothesis. We discuss specific important elements in the skin (FLG and other skin barrier gene mutations, Langerhans cells, type 2 innate lymphoid cells, IL-33, TSLP) that have important roles in the development of allergic responses as well as the body of evidence on environmental allergen exposure and how this can sensitize an individual. Given the link between skin barrier impairment, atopic dermatitis, food allergy, allergic asthma, and allergic rhinitis, it is logical that restoring the skin barrier and prevention or treating atopic dermatitis would have beneficial effects on prevention of related allergic diseases, particularly food allergy. We present the experimental and human studies that have evaluated this approach and discuss various factors which may influence the success of these approaches, such as the type of emollient chosen for the intervention, the role of managing skin inflammation, and differences between primary and secondary prevention of atopic dermatitis to achieve the desired outcome.

How does parental history of atopic disease predict the risk of atopic dermatitis in a child? A systematic review and meta-analysis

BACKGROUND

Parental history of atopic disease is a well-established risk factor for the development of atopic dermatitis (AD), but several aspects of this association remain unclear.

OBJECTIVE

We sought to determine the association of parental history of atopic disease with AD in offspring.

METHODS

We searched PubMed and EMBASE through June 2018 for relevant records and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled odds ratios (ORs) with 95% CI were calculated using random-effects models.

RESULTS

A total of 163 records covering 149 unique studies were included. Of these, 119 studies were included in the meta-analysis. Individuals with parental history of atopic disease had increased odds of AD (OR, 1.81; 95% CI, 1.65-1.99). Parental asthma (OR, 1.56; 95% CI, 1.18-2.05) and allergic rhinitis (OR, 1.68; 95% CI, 1.34-2.11) had a smaller effect than AD (OR, 3.30; 95% CI, 2.46-4.42). The effect of maternal and paternal history was comparable for all atopic diseases. An increase in odds was observed when comparing the effect of having 1 (OR, 1.30; 95% CI, 1.15-1.47) or 2 atopic parents (OR, 2.08; 95% CI, 1.83-2.36), as well as having a parent with 1 (OR, 1.49; 95% CI, 1.28-1.74) or more atopic diseases (OR, 2.32; 95% CI, 1.92-2.81).

CONCLUSIONS

This study provides evidence-based risk estimates that may guide physicians who counsel parents with a history of atopic disease about their children's risk of AD. This information is of particular importance for future efforts toward establishing prophylactic interventions for AD on a general population level.