Paediatric asthma prevalence: The first national population-based survey in Iran

Prevalence of asthma among children and adolescents in WHO's Eastern Mediterranean Region: a meta-analysis of over 0.5 million participants

OBJECTIVE

This study aims to evaluate the epidemiology of asthma among children and adolescents in the Eastern Mediterranean Region.

METHODS

Exhaustive searches were conducted across databases, including PubMed, Scopus, Web of Knowledge Core Collection, Embase, and Google Scholar. The selection criteria included studies reporting asthma prevalence in individuals aged 0 to 19 years, using validated questionnaires. Data were extracted and synthesized using the DerSimonian and Laird random effects model.

RESULTS

The overall prevalence of asthma in Eastern Mediterranean Regional Office (EMRO) countries, among the 514,468 children and adolescents included in this meta-analysis, was 10.61%, synthesized from 95 studies. Among the countries studied, Qatar exhibited the highest prevalence at 16.69%, followed by Saudi Arabia at 16.57%, Iraq at 16.22%, Oman at 15.20%, and Afghanistan at 14.90%. Adolescents showed a slightly higher prevalence of asthma at 10.10% compared to children at 9.70%. Boys exhibited a higher prevalence at 11.48% compared to girls at 9.75%. Urban areas demonstrated a higher prevalence at 11.27% than rural areas at 8.29%.

CONCLUSION

Efforts to reduce asthma prevalence in Arab countries and address underdiagnosis in African nations within the EMRO are crucial. Targeted interventions should focus on addressing environmental triggers and improving access to healthcare. Enhanced diagnostic capabilities and healthcare infrastructure are necessary in African countries. Collaborative action is essential to alleviate the asthma burden and promote respiratory health across the EMRO region.

Helicobacter pylori infection and small intestinal bacterial overgrowth: a systematic review and meta-analysis

BACKGROUND

There is a link between Helicobacter pylori (HP) infection and small intestinal bacterial overgrowth (SIBO) with nonspecific digestive symptoms. Nonetheless, whether HP infection is associated with SIBO in adults remains unclear. Based on a meta-analysis, we evaluated this relationship.

RESULTS

Observational studies relevant to our research were identified by searching PubMed, Embase, the Cochrane Library, and the Web of Science. We evaluated between-study heterogeneity using the Cochrane Q test and estimated the I2 statistic. Random-effects models were used when significant heterogeneity was observed; otherwise, fixed-effects models were used. Ten datasets from eight studies, including 874 patients, were involved in the meta-analysis. It was shown that HP infection was related to a higher odds of SIBO (odds ratio [OR]: 1.82, 95% confidence interval: 1.29 to 2.58, p < 0.001) with mild heterogeneity (p for Cochrane Q test = 0.11, I2 = 7%). Subgroup analyses showed that HP infection was related to SIBO in young patients (mean age < 48 years, OR: 2.68, 95% CI: 1.67 to 4.28, p < 0.001; I2 = 15%) but not in older patients (mean age ≥ 48 years, OR: 1.15, 95% CI: 0.69 to 1.92, p < 0.60; I2 = 1%; p for subgroup difference = 0.02). Subgroup analyses further indicated that the association was not significantly affected by the country of study, comorbidities, exposure to proton pump inhibitors, or methods of evaluating HP infection and SIBO.

CONCLUSIONS

HP infection may be related to SIBO in adults, which supports the detection of SIBO in patients with digestive symptoms and HP infection.

Association Between Pet Keeping and Current Asthma Among Adolescents Living in Yazd; Evidence from Global Asthma Network (GAN) 2020 Cross-sectional Study

BACKGROUND

The relationship between current pet keeping and allergic diseases, including bronchial asthma in adolescents, is controversial. This study was conducted to evaluate these associations among children aged 13-14 years in Yazd.

METHODS

This study is part of a multicenter cross-sectional study of the Global Asthma Network (GAN) in Yazd, Iran, in 2020, in which 5141adolescents enrolled. Information on respiratory symptoms and pet-keeping (dog/cat/birds) was obtained by a questionnaire derived from the GAN standard questionnaire.

RESULTS

Of 5141 participants who completed the study, 1800 (35%) children kept pets during the last year. Birds were the most common pet kept by adolescents (88%). Severe asthma was more common in bird and cat keepers (P=0.003 and P=0.034, respectively) than dog keepers. Furthermore, there was a statistically significant association between study-defined current asthma and cat keeping, but not bird or dog ownership (P=0.02). Moreover, we found that current any pet-keeping (birds, cats, dogs) was associated with a higher prevalence of asthma-related symptoms, including wheezing, night dry cough, and exercise-induced wheezing in the past year (P=0.002, P=0.000 and P=0.000 respectively).

CONCLUSION

Current any pet-keeping is associated with asthma-related symptoms. Additionally, cat keeping had a significant association with study-defined current asthma. The current keeping of birds, as the most common pet in our area, or cat keeping increases the risk of severe asthma in adolescents. Therefore, as an important health tip, this needs to be reminded to families by health care providers.

Clinical, Immunological, and Genetic Findings in Iranian Patients with MHC-II Deficiency: Confirmation of c.162delG RFXANK Founder Mutation in the Iranian Population

PURPOSE

Major histocompatibility complex class II (MHC-II) deficiency is a rare inborn error of immunity (IEI). Impaired antigen presentation to CD4 + T cells results in combined immunodeficiency (CID). Patients typically present with severe respiratory and gastrointestinal tract infections at early ages. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy.

METHODS

We describe the clinical, immunologic, and genetic features of eighteen unrelated Iranian patients with MHC-II deficiency.

RESULTS

Consanguinity was present in all affected families. The median age at the initial presentation was 5.5 months (range 7 days to 18 years). The main symptoms included failure to thrive, persistent diarrhea, and pneumonia. Autoimmune and neurologic features were also documented in about one-third of the patients, respectively. Thirteen patients carried RFXANK gene mutations, two carried RFX5 gene mutations, and three carried a RFXAP gene mutation. Six patients shared the same RFXANK founder mutation (c.162delG); limited to the Iranian population and dated to approximately 1296 years ago. Four of the patients underwent HSCT; three of them are alive. On the other hand, nine of the fourteen patients who did not undergo HSCT had a poor prognosis and died.

CONCLUSION

MHC-II deficiency is not rare in Iran, with a high rate of consanguinity. It should be considered in the differential diagnosis of CID at any age. With the limited access to HSCT and its variable results in MHC-II deficiency, implementing genetic counseling and family planning for the affected families are mandatory. We are better determined to study the c.162delG RFXANK heterozygous mutation frequency in the Iranian population.

Evaluation of the association between asthma and non-neurogenic urinary incontinence in children; a case-control study

BACKGROUND

Asthma is the most common chronic disease in children. Asthma can lead to sleep disorders and psychiatric issues, which are often accompanied by urinary incontinence in children. Furthermore, several studies have shown a relationship between allergic diseases and urinary incontinence. This study aims to examine the association between asthma and non-neurogenic urinary incontinence.

MATERIALS AND METHODS

This case-control study included 314 children over three years old referred to Amir Kabir Hospital; 157 with asthma and 157 without asthma. After explaining each urinary disorder in accordace with the International Children's Continence Society's definitions, parents and children were asked about their presence. The disorders included monosymptomatic nocturnal enuresis(MNE), nonmonosymptomatic nocturnal enuresis (NMNE), vaginal reflux (VR), pollakiuria, infrequent voiding, giggle incontinence (GI), and overactive bladder (OAB). The analysis was performed using Stata 16.

RESULTS

The average age of the children was 8.19 ± 3.15 years. Patients with asthma (p = 0.0001) and GI (p = 0.027) had a considerably lower average age than patients without these disorders. Asthma and urinary incontinence, including NMNE, Infrequent voiding, and OAB, were significantly correlated (p = 0.017, 0.013, and 0.0001, respectively). Moreover, the association between MNE and asthma was significant in males (p = 0.047).

CONCLUSION

Due to the relationship between asthma and urinary incontinence, children with asthma must be evaluated for the presence of urinary disorders and, if present, receive the proper treatment in order to improve their quality of life.

Airway Bacterial Biodiversity in Exhaled Breath Condensates of Asthmatic Children-Does It Differ from the Healthy Ones?

Asthma etiopathology is still not fully determined. One of its possible causes can be found in airway microbiome dysbiosis. The study's purpose was to determine whether there are any significant differences in the bacterial microbiome diversity of lower airways microbiota of asthmatic children, since knowledge of this topic is very scarce. To the authors' knowledge, this is the first research using exhaled breath condensates in children's lower airways for bacterial assessment. Exhaled breath condensates (EBC) and oropharyngeal swabs were obtained from pediatric asthmatic patients and a healthy group (n = 38, 19 vs. 19). The microbial assessment was conducted through genetic material PCR amplification, followed by bacterial 16S rRNA amplicon sequencing. Collected data were analyzed, in terms of taxonomy and alpha and beta diversity between assessed groups. Swab samples are characterized by higher species richness compared to exhaled breath condensates (Shannon diversity index (mean 4.11 vs. 2.867, p = 9.108 × 10^-8), observed features (mean 77.4 vs. 17.3, p = 5.572 × 10^-11), and Faith's phylogenetic diversity (mean 7.686 vs. 3.280 p = 1.296 × 10^-10)). Asthmatic children had a higher abundance of bacterial species (Shannon diversity index, mean 3.029 vs. 2.642, p = 0.026) but more even distribution (Pielou's evenness, mean 0.742 vs. 0.648, p = 0.002) in EBC than healthy ones; the same results were observed within pediatric patients born naturally within EBC samples. In children with a positive family history of allergic diseases, alpha diversity of lower airway material was increased (Shannon's diversity index p = 0.026, Faith's phylogenetic diversity p = 0.011, observed features p = 0.003). Class Gammaproteobacteria and Bacilli were less abundant among asthmatics in the exhaled breath samples. The most dominant bacteria on a phylum level in both sample types were Firmicutes, followed by Proteobacteria and Actinobacteriota. The obtained outcome of higher bacterial diversity of lower airways among asthmatic patients indicates a further need for future studies of microbiota connection with disease pathogenesis.

Geoclimatic risk factors for childhood asthma hospitalization in southwest of Iran

BACKGROUND

Asthma is a chronic respiratory disease resulting from a complex interaction between genetic and environmental factors. Among environmental factors, climatic and geographical variations have an important role in increasing asthma hospitalization. The current study aimed to investigate the effect of geoclimatic factors on the occurrence of childhood asthma hospitalization in Fars province, southwest Iran.

METHOD

We mapped the addresses of 211 hospitalized patients with childhood asthma (2016-2019) and investigated the effects of different temperature models, mean annual rainfall and humidity, number of frosty and rainy days, evaporation, slope, and land covers on the occurrence of childhood asthma hospitalization using a geographical information system. The Kriging and Spline methods have been used for generating interpolated models. Data were analyzed using logistic regression.

RESULTS

In the multivariate model, urban setting was recognized as the most important childhood asthma hospitalization predictor (p < 0.001, odds ration [OR] = 35.044, confidence interval [CI] = 9.096-135.018). The slope was considered the determinant of childhood asthma hospitalization when analyzed independently and its increase was associated with decreased childhood asthma hospitalization (p  = 0.01, OR = 0.914, CI = 0.849-0.984).

CONCLUSION

In the current study, the urban setting was the most important risk factor associated with increased childhood asthma hospitalization.

Assessing the prevalence and severity of asthma, rhinitis, and eczema among schoolchildren (6-7 and 13-14 years old) in Khuzestan, Iran: a cross-sectional survey

Background

Asthma and allergic complications are the most common chronic disorders in children and adolescents. This study aimed to determine the prevalence and severity of asthma, allergic rhinitis, eczema among schoolchildren, and some related risk factors.

Methods

The cross-sectional study was performed in 2019 and involved 4000 students aged 6–7 years and 4000 students aged 13–14 years (both girls and boys) from urban schools in Khuzestan Province, southwestern Iran. We used the multi-stage sampling method. Data were collected using the Persian version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.

Results

The prevalence of current wheeze, wheeze ever and asthma ever in the age group of 6–7 years was 3.8, 4.5, and 1.8%, respectively; in the age group of 13–14 years, it was 4.4, 5.9, and 3.4, respectively. In terms of gender, males (4.9, 6.0, and 2.7 percent, respectively) had substantially higher rates of current wheeze, wheeze ever, and asthma ever compared to the girls (2.8, 3.6, and 2.0 percent, respectively) (p < 0.001). The prevalence of rhinitis, Hay fever, and eczema among young people was 5.3%, 3.5%, and 1.0%, respectively. Current wheeze was more common in children with allergic rhinitis in the last 12 months (30.3% vs. 2.7%, p < 0.001), Hay fever (32.8% vs. 0.3%, p < 0.001) and eczema (27.8% vs 3.8%, p < 0.001), compared to children who did not.

Conclusions

The prevalence and severity of asthma symptoms were significantly associated with allergic rhinitis, eczema, and gender.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03520-x.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

Risk factors for current wheeze among school children (6–7 and 13–14 years old) in Khuzestan, Iran

Objectives

In recent years, there has been a clear trend of increasing allergic diseases especially in children, and developing countries are no exception. Thepresentstudy sought to determine the risk factors associated with wheezing among school children aged 6–7 and 13–14 years living in Khuzestan Province, Iran.

Study design

Cross-sectional.

Methods

Data for this cross-sectional study is the history of wheeze in the last 12 months. The participants included 6-7- and 13-14-year-old girls and boys studying in urban schools in Khuzestan Province in 2019. We collected the data using the multi stage sampling technique as suggested in the International Study of Asthma and Allergies in Childhood (ISAAC). The research reviewed the literature and consulted experts to collect the risk factors for demographic and clinical information, environmental exposure and lifestyle.

Results

Eight thousand questionnaires were handed out to both age groups, of which 7344 were completed. Two hundred ninety-nine (4.1 %) of the participants had current wheeze. Three-point four percent (124 individuals) in the 6–7 year age group and 4.8 % in the 13–14-year-old age group had current wheezing. The results of the logistic regression model suggest that the most significant risk factors associated with the chance of developing current wheeze in the both age groups are: being male (OR: 1.46, 95 % CI: 1.12–1.88), being from employed mother families (OR: 1.50, 95 %, CI:1.05–2.08), property ownership (OR:1.36, 95 %, CI:1.04–1.79) bugs in the property (OR: 1.29, 95 %, CI:0.99–1.70) mold in the property (OR: 1.75, 95 %, CI:1.12–2.76), pet(s) in the student's bedroom (OR: 1.75, 95 %, CI: 0.97–3.14), a family history of asthma and allergic diseases (OR: 2.20, 95 %, CI: 1.69–2.87), tobacco smoke exposures in the property (OR: 1.43, 95 %, CI:1.04–1.96), having allergic rhinitis (OR: 7.86, 95 % CI: 5.89–10.50) and eczema (OR: 3.85, 95 % CI: 2.10–7.08).

Conclusions

Families are suggested to adopt strategies to reduce exposure to outdoor air pollutants and contain indoor allergens. More studies are necessary to further explore the effects of modifying and changing these risk factors.

•

3.4 % in the 6–7 year age group and 4.8 % in the 13–14 year age group had current wheezing.

•

In both age groups, current wheeze is more common in boys than girls.

•

Mold in the home, pet in the bedroom and tobacco smoke exposures are the most important risk factors for current wheeze.

The Impact of Motivational Interview on Self-Efficacy, Beliefs About Medicines and Medication Adherence Among Adolescents with Asthma: A Randomized Controlled Trial

PURPOSE

This study aimed to determine the impact of MI on self-efficacy, beliefs about medicines and medication adherence among adolescents with asthma.

METHOD

This randomized controlled trial conducted on 52 adolescents with asthma referring to the Pediatric Medical Center in Tehran, Iran. They were randomly assigned to the control and intervention groups. The educational intervention consisted of 3 one-hour sessions per week, which was held individually in the areas of medication adherence, beliefs about medicines and self-efficacy. Four validated questionnaires including demographic characteristics, medication adherence, self-efficacy and beliefs about medicines were completed by self-report both before the MI and 40 days after the end of the intervention.

RESULTS

In the baseline, the two groups were homogeneous in terms of demographic characteristics and outcome measures. At the post-test, the mean scores of the three outcome measures in the intervention group were reported higher compared to the scores in the control group (p < 0.05). The difference between the mean scores in medication adherence, beliefs about medicines and self-efficacy in the post-test between the two groups, even with the elimination of the effect pre-test scores, were significant (p < 0.05).

CONCLUSIONS

The results of this study showed that MI can be effective in improving medication adherence, beliefs about medicines, and self-efficacy.

PRACTICE IMPLICATIONS

The primary goal in the treatment of patients with asthma is asthma control by using corticosteroids. MI is one of the interventions that can simultaneously provide motivation, readiness, beliefs about medicine and self-efficacy for behavioral changes (medication adherence) in patients with asthma.

Spatiotemporal variability of exposure to secondhand smoke in Iran during 2009-2020: a systematic review

The present study aimed to provide a systematic review of studies on the prevalence of secondhand smoke (SHS) exposure in the Iran population as a serious indoor health hazard. A literature review of studies that considered SHS exposure, available in multiple electronic databases including Web of Science, PubMed, and Scopus published 2009-2020 in English and two Persian databases (SID and Magiran), was carried out following the PRISMA recommendations. A total of 55 studies were included based on the inclusion and exclusion criteria and the quality assessment. The results showed no specific decrease in the prevalence of exposure to secondhand smoke in Iran; however, it appeared that the exposure has been increasing. Distribution of studies in terms of age group revealed that most studies (38%) investigated adults (more than 18 years old), while 34% of the studies considered less than 18 years of age group and a single article considered infants (6-24 months). Based on the present study results, a large population of Iran was exposed to SHS. Moreover, based on Iran's STEPs 2016 (Stepwise Non-communicable Diseases Risk Factors Survey in Iran) study, the overall prevalence of SHS exposure at home (57.5%) was higher than in workplaces (49.2%). The results of the present study recommended that protection measures should be comprehensive in terms of exposure places, and since the exposure prevalence in some provinces was higher than the others, it is especially important to consider the local measures and cultural aspects in SHS control programs.

The Prevalence of Asthma among Iranian Children and Adolescent: A Systematic Review and Meta-Analysis

BACKGROUND

Asthma is an important reason for hospitalization in children aged under five years. Information about the current status of asthma in Iranian children can help the Iranian health sector plan carefully and prevent asthma incidence by educating the families. The present systematic review and meta-analysis is aimed at estimating asthma prevalence in Iranian children and adolescents.

METHOD

Data were found using keywords such as prevalence, epidemiology, asthma, adolescent, children, pediatrics, Iran in Web of Science, Scopus, PubMed, Cochrane, and Embase databases. Three national databases, including Magiran, Barakat Pharmed Co (Iran medex), and Scientific Information Databank (SID) were searched until 1 October 2020. Cross-sectional and original studies were included in the study, and then, quality assessment was done using the National Institutes of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. A pooled estimated prevalence of asthma was calculated using Der Simonian-Laird random model. Egger's test was used to evaluate publication bias. The data were analyzed using the STATA software version 16.

RESULTS

30 studies were selected and investigated. The prevalence of asthma in children and adolescents was 6% and 8%, and the prevalence in boys and girls was 9% and 8%, respectively. Among the asthma symptoms, wheezing had the most prevalence (17% in children and 19% in adolescents) and sleep disturbance had the lowest prevalence (6% in children and 6% in adolescents).

CONCLUSION

The prevalence of asthma in Iranian children and adolescents is lower than in the world. Existing strategies should be pursued followed. Also, guidelines for asthma control and prevention should be considered in the future.

Prevalence of Respiratory Viral Infections in Children with Asthma in Kermanshah

Background: Asthma is a chronic inflammatory disorder of lung airways, affecting about 300 million people worldwide. Several risk factors are involved in asthma development, such as environmental allergens, genetic susceptibility, and respiratory viral infections. Viral infections induce NF-kB and inflammatory pathways that lead to the production of cytokines, chemokines, and inflammatory proteins and, finally, a reduction of lung volume and function. Objectives: The aim of this study was to evaluate viral infections’ prevalence in children with asthma from 2016 to 2017. Methods: One hundred throat swab samples were collected from asthmatic children. Extraction of RNA and cDNA synthesis were performed to recognize parainfluenza viruses, rhinoviruses, influenza viruses, and respiratory syncytial virus (RSV) using real-time PCR. Also, the associations of age, sex, and other studied factors with asthmatic attacks were evaluated. Results: In this study, 41 viruses were detected, including 21 cases of rhinoviruses (51.22%), 10 cases of parainfluenza (24.39%), seven cases of respiratory syncytial virus (17.07%), and three cases of the influenza virus (7.32%). Regarding seasonal incidence, the prevalence of the viruses was high in autumn and winter, and there was a significant relationship between seasonal incidence and gender. However, there were no statistically significant relationships between the prevalence of the viruses and age or gender. Conclusions: The most important viral causes of childhood asthma in this study were found to be rhinoviruses, followed by parainfluenza. The lowest prevalence was related to the RSV and influenza virus, which the two viruses also showed the lowest seasonal outbreaks. Therefore, it can be said that with an increase in the seasonal incidence of respiratory viruses, the effects of these viruses will be greater on asthma.

Socio-environmental profile of child and adolescents sensitized by house dust mite in northeast of Brazil

INTRODUCTION

The association regarding the atopic sensitization to mite aeroallergens and the socio-environmental features is still inconsistent.

OBJECTIVES

We analyzed the role played by socioeconomic and environmental factors in the prevalence of sensitization to house dust mite (HDM) allergens, and associated with the risk of developing asthma symptoms.

PATIENTS AND METHODS

This is a case-control study conducted with 108 patients, aged 1-17. We inquired about family habits, socioeconomic and environmental features. We applied the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

We observed patients sensitized to all HDM tested, Derp (42%), Derf (37%) and Blot (33%). Middle family income (OR: 2.74; CI95%: 1.127-6.684), exposure to dog (OR: 3.758, CI95%: 1.127-6.684) and artificial climatization (OR: 4.319, CI95%: 1.398-13.348) were associated with sensitization to Derp. We also observed protective factors, such as sharing of dormitories, washing cycle for bedspreads and the presence of basic sanitation. An increased risk of sensitization to Derf was associated with Blot sensitization (OR: 3.172, CI95%: 1.083-9.292) and presence of mold on the walls (OR: 3.095, CI95%: 1.063-9.008). A protective factor was dormitory sharing. For sensitization to Blot, we observed an increase in the risk associated with Derp sensitization (OR: 3.462, CI95%: 1.191-10.061) and exposure to dog (OR: 3.255, CI95%: 0.987-10.736). In addition, sensitization to Blot increases the risk of developing asthma symptoms (OR: 2.732, CI95%: 0.981-7.606).

CONCLUSION

Our data show distinct sociodemographic and environmental relations that lead to HDM sensitization and increased probability of development of allergic diseases.