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Introduction: Evidence on the early life risk factors of adult CRS, and the history of asthma and allergies across the life course, is limited., Aim: To investigate relationships between respiratory infective/allergic conditions in childhood, and asthma and allergies across the life course and CRS in middle age., Methods: Data were from the population-based Tasmanian Longitudinal Health Study (TAHS) cohort, first studied in 1968 when aged 6-7 years (n = 8583) and serially followed into middle age (n = 3609). Using a well-accepted epidemiological definition, participants were assigned a CRS-severity subtype at age 53: no sinusitis/CRS (reference); past doctor diagnosis only; current symptoms without doctor diagnosis; and doctor-diagnosed CRS with current symptoms. Relationships with infective/allergic respiratory illnesses at age 7, and previously published asthma-allergy trajectories from 7 to 53 years, were examined using multinominal regression., Results: In middle age, 5.8% reported current CRS symptoms with 2.5% doctor-diagnosed. Childhood conditions associated with symptomatic doctor-diagnosed CRS included frequent head colds (multinomial odds ratio [mOR] = 2.04 (95% confidence interval [95% CI]: 1.24, 3.37)), frequent tonsillitis (mOR = 1.61 [95% CI: 1.00, 2.59]) and current childhood asthma (mOR = 2.23 [95% CI: 1.25, 3.98]). Life course trajectories that featured late-onset or persistent asthma and allergies were associated with all CRS subtypes in middle age; early-onset persistent asthma and allergies (mOR = 6.74, 95% CI: 2.76, 16.4); late-onset asthma allergies (mOR = 15.9, 95% CI: 8.06, 31.4), and late-onset hayfever (mOR = 3.02, 95% CI: 1.51, 6.06) were associated with symptomatic doctor-diagnosed CRS., Conclusion: Current asthma, frequent head colds and tonsillitis at age 7 could signal a susceptible child who is at higher risk for CRS in mid-adult life and who might benefit from closer monitoring and/or proactive management. Concurrent asthma and allergies were strongly associated and are potential treatable traits of adult CRS., (© 2024 The Author(s). Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: There are no studies of longitudinal immunoglobulin measurements in a population-based cohort alongside challenge-confirmed peanut allergy outcomes. Little is known about biomarkers for identifying naturally resolving peanut allergy during childhood., Objectives: To measure longitudinal trends in whole peanut and component Ara h 2 sIgE and sIgG 4 in the first 10 years of life, in a population cohort of children with challenge-confirmed peanut allergy, and to determine whether peanut-specific immunoglobulin levels or trends are associated with peanut allergy persistence or resolution by 10 years of age., Methods: One-year-old infants with challenge-confirmed peanut allergy (n = 156) from the HealthNuts study (n = 5276) were prospectively followed at ages 4, 6, and 10 years with questionnaires, skin prick tests, oral food challenges, and plasma total-IgE, sIgE and sIgG 4 to peanut and Ara h 2., Results: Peanut allergy resolved in 33.9% (95% CI = 25.3%, 43.3%) of children by 10 years old with most resolving (97.4%, 95% CI = 86.5%, 99.9%) by 6 years old. Decreasing Ara h 2 sIgE (p = .01) and increasing peanut sIgG 4 (p < .001), Ara h 2 sIgG 4 (p = .01), peanut sIgG 4 /sIgE (p < .001) and Ara h 2 sIgG 4 /sIgE (p < .001) from 1 to 10 years of age were associated with peanut allergy resolution. Peanut sIgE measured at 1 year old had the greatest prognostic value (AUC = 0.75 [95% CI = 0.66, 0.82]); however, no single threshold produced both high sensitivity and specificity., Conclusion: One third of infant peanut allergy resolved by 10 years of age. Decreasing sIgE and sIgG 4 to peanut and Ara h 2 over time were associated with natural resolution of peanut allergy. However, biomarker levels at diagnosis were not strongly associated with the natural history of peanut allergy., (© 2024 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: The extent to which biomarkers of asthma activity persist in spontaneous asthma remission and whether such markers are associated with future respiratory outcomes remained unclear. We investigated the association between sub-clinical inflammation in adults with spontaneous asthma remission and future asthma relapse and lung function decline., Methods: The Tasmanian Longitudinal Health Study is a population-based cohort (n = 8583). Biomarkers of systemic inflammation were measured on participants at age 45, and latent profile analysis was used to identify cytokine profiles. Bronchial hyperresponsiveness (BHR) and nitric oxide products in exhaled breath condensate (EBC NOx) were measured at age 50. Participants with spontaneous asthma remission at ages 45 (n = 466) and 50 (n = 318) were re-evaluated at age 53, and associations between baseline inflammatory biomarkers and subsequent asthma relapse and lung function decline were assessed., Results: We identified three cytokine profiles in adults with spontaneous asthma remission: average (34%), Th2-high (42%) and Th2-low (24%). Compared to the average profile, a Th2-high profile was associated with accelerated decline in post-BD FEV 1 /FVC (MD -0.18% predicted per-year; 95% CI -0.33, -0.02), while a Th2-low profile was associated with accelerated decline in both post-BD FEV 1 (-0.41%; -0.75, -0.06) and post-BD FVC (-0.31%; -0.62, 0.01). BHR and high TNF-α during spontaneous remission were associated with an increased risk of asthma relapse. In contrast, we found no evidence of association between EBC NOx and either asthma relapse or lung function decline., Conclusion: BHR and serum inflammatory cytokines have prognostic value in adults with spontaneous asthma remission. At-risk individuals with BHR, Th2-high or Th2-low cytokine profiles may benefit from closer monitoring and on-going follow-up., (© 2022 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: There is limited information on risk factors for eczema in adults. Recent evidence suggests that air pollution may be associated with increased incidence of eczema in adults. We aimed to assess this possible association., Methods: Ambient air pollution exposures (distance from a major road, nitrogen dioxide [NO 2 ], fine particulate matter with an aerodynamic diameter ≤2.5 µm [PM 2.5 ]) were assessed for the residential address of Tasmanian Longitudinal Health Study participants at ages 43 and 53 years. Eczema incidence (onset after age 43 years), prevalence (at 53 years), and persistence were assessed from surveys, while IgE sensitization was assessed using skin prick tests. The presence or absence of eczema and sensitization was classified into four groups: no atopy or eczema, atopy alone, non-atopic eczema, and atopic eczema. Adjusted logistic and multinomial regression models were fitted to estimate associations between ambient air pollution and eczema, and interaction by sex was assessed., Results: Of 3153 participants in both follow-ups, 2369 had valid skin prick tests. For males, a 2.3 ppb increase in baselineNO 2 was associated with increased odds of prevalent eczema (OR = 1.15 [95% CI 0.98-1.36]) and prevalent atopic eczema (OR = 1.26 [1.00-1.59]). These associations were not seen in females (p for interaction = 0.08, <0.01). For both sexes, a 1.6 µg/m 3 increase in PM 2.5 exposure at follow-up was associated with increased odds of aeroallergen sensitization (OR = 1.15 [1.03-1.30])., Conclusion: Increased exposure to residential ambient air pollutants was associated with an increased odds of eczema, only in males, and aeroallergen sensitization in both genders., (© 2021 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background and Objective: As the rise in prevalence of allergic diseases worldwide corresponds in time with increasing infant vaccination, it has been hypothesized that childhood vaccination may increase the risk of allergic disease. We aimed to synthesize the literature on the association between childhood vaccination and allergy., Design: We searched the electronic databases PubMed and EMBASE (January 1946-January 2018) using vaccination and allergy terms., Methods: Two authors selected papers according to the inclusion criteria. Pooled effects across studies were estimated using random-effects meta-analysis. Due to inadequate number of homogeneous publications on newer and underused vaccines, meta-analysis was limited to allergic outcomes following administration of (Bacillus Calmette-Guérin) BCG, measles or pertussis vaccination. The review was prospectively registered in the PROSPERO systematic review registry (NO: CRD42017071009)., Results: A total of 35 publications based on cohort studies and 7 publications based on randomized controlled trials (RCTs) met the inclusion criteria. RCTs: From 2 studies, early vaccination with BCG vaccine was associated with a reduced risk of eczema (RR = 0.83; 95% CI = 0.73-0.93; I 2  = 0%) but not food allergy or asthma. No association was found between pertussis vaccine and any allergic outcome based on a single RCT., Cohort Studies: Childhood measles vaccination was associated with a reduced risk of eczema (RR = 0.65; 95% CI = 0.47-0.90, I 2  = 0.0%), asthma (RR = 0.78; 95% CI = 0.62-0.98, I 2  = 93.9%) and, with a similar, statistically non-significant reduction in sensitization (RR = 0.78; 95% CI = 0.61-1.01, I 2  = 19.4%)., Conclusions: We found no evidence that childhood vaccination with commonly administered vaccines was associated with increased risk of later allergic disease. Our results from pooled analysis of both RCTs and cohort studies suggest that vaccination with BCG and measles vaccines were associated with a reduced risk of eczema., (© 2021 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background: The association between grass pollen exposure and early markers of asthma exacerbations such as lung function changes and increase in airway inflammation is limited. We investigated the associations between short-term grass pollen exposure and lung function and airway inflammation in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization, age, and other environmental factors., Methods: Cross-sectional and short-term analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO) and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression., Results: Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF 25%-75% ) and FEV 1 /FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) were associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever, and pollen sensitization., Conclusion: Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure. Adults and individuals with asthma, hay fever, and pollen sensitization may be at higher risk., (© 2020 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background: Exposure to high levels of pollen in infancy is a risk factor for allergic respiratory diseases in later childhood, but effects on lung function are not fully understood. We aim to examine associations between grass pollen exposure in the first months of life and lung function at 12 and 18 years, and explore potential modification., Methods: Using the Melbourne Atopy Cohort Study, a birth cohort of children with a family history of allergic diseases, we modeled the association between cumulative grass pollen exposure up to 3 months after birth, on FEV 1 , FVC, and FEV 1 /FVC ratio at 12 and 18 years. We also assessed modifying effects of residential greenness levels (derived from satellite imagery), asthma, and early life sensitization to ryegrass., Results: Grass pollen exposure in the first 7 days was associated with a reduction in FEV 1 (-15.5 mL; 95% CI: -27.6, -3.3 per doubling of pollen count) and FVC (-20.8 mL; -35.4, -6.1) at 12 years, but not at 18 years. Increase in cumulative grass pollen exposure up to 3 months was negatively associated with FVC at 12 and 18. Exposure to high residential greenness modified the association at 18 years., Conclusion: Early exposure to grass pollen was associated with decreased lung function in children and adolescents. Targeted interventions for pollen avoidance strategies that take into account local topography could be implemented alongside other clinical interventions such as immunotherapy., (© 2019 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Introduction: Dietary polyunsaturated fatty acids (PUFAs) have immunoregulatory properties. Breast milk is rich in PUFA, and it has been hypothesized that these PUFAs may be important in the aetiology of allergic diseases. Despite a growing body of evidence, the associations between breast milk PUFA and allergic disease have not previously been systematically reviewed., Methods: The search was performed in PubMed and EMBASE databases using breastfeeding, fatty acid and allergic disease terms. Two authors were involved in selecting papers for review according to the inclusion criteria and extracting information on study characteristics and measures of association. Only studies that reported numeric associations between concentration of breast milk fatty acids and allergic disease outcomes were included., Results: A total of 18 papers met the inclusion criteria, reporting results from 15 study populations. The majority were cohort studies (n=11), with data from only two case-control and two cross-sectional studies. Sample size varied between 30 and 352 participants, and follow-up time of the cohorts varied between 3 months and 14 years. Nine studies reported on eczema, seven reported on sensitization, and only five reported on asthma/wheeze. There was heterogeneity among studies in terms of presenting the association between PUFA and allergy; therefore, estimates could not be pooled. Only a few studies observed associations between n-3 and n-6 PUFAs and allergic disease, and the magnitude of this effect varied greatly., Conclusions: There is insufficient evidence to suggest that colostrum or breast milk polyunsaturated fatty acids influence the risk of childhood allergic diseases., (© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background: It has been hypothesized that n-3 PUFA in breast milk may assist immune and lung development. There are very limited data on possible long-term effects on allergic disease and lung function. The aim was to investigate associations of n-3 and n-6 PUFA levels in colostrum and breast milk with allergic disease and lung function at ages 12 and 18 years., Methods: Polyunsaturated fatty acids were measured in 194 colostrum samples and in 118 three-month expressed breast milk samples from mothers of children enrolled in the Melbourne Atopy Cohort (MACS) Study, a high-risk birth cohort study. Associations with allergic diseases, skin prick tests and lung function assessed at 12 and 18 years were estimated using multivariable regression., Results: Higher levels of n-3 but not n-6 PUFAs in colostrum were associated with a trend towards increased odds of allergic diseases, with strong associations observed for allergic rhinitis at 12 (OR = 5.69[95% CI: 1.83,17.60] per weight%) and 18 years (4.43[1.46,13.39]) and eczema at 18 years (9.89[1.44, 68.49]). Higher levels of colostrum n-3 PUFAs were associated with reduced sensitization (3.37[1.18, 9.6]), mean FEV 1 (-166 ml [-332, -1]) and FEV 1 /FVC ratio (-4.6%, [-8.1, -1.1]) at 12 years., Conclusion: Higher levels of colostrum n-3 PUFAs were associated with increased risks of allergic rhinitis and eczema up to 18 years, and sensitization and reduced lung function at 12 years. As residual confounding may have caused these associations, they should be replicated, but these results could indicate that strategies that increase maternal n-3 PUFA intake may not aid in allergic disease prevention., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Oxidative stress has a recognized role in the pathophysiology of asthma. Recently, interest has increased in the assessment of pH and airway oxidative stress markers. Collection of exhaled breath condensate (EBC) and quantification of biomarkers in breath samples can potentially indicate lung disease activity and help in the study of airway inflammation, and asthma severity. Levels of oxidative stress markers in the EBC have been systematically evaluated in children with asthma; however, there is no such systematic review conducted for adult asthma. A systematic review of oxidative stress markers measured in EBC of adult asthma was conducted, and studies were identified by searching MEDLINE and SCOPUS databases. Sixteen papers met the inclusion criteria. Concentrations of exhaled hydrogen ions, nitric oxide products, hydrogen peroxide and 8-isoprostanes were generally elevated and related to lower lung function tests in adults with asthma compared to healthy subjects. Assessment of EBC markers may be a noninvasive approach to evaluate airway inflammation, exacerbations, and disease severity of asthma, and to monitor the effectiveness of anti-inflammatory treatment regimens. Longitudinal studies, using standardized analytical techniques for EBC collection, are required to establish reference values for the interpretation of EBC markers in the context of asthma., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Epidemiological evidence suggests that routine vaccinations can have nontargeted effects on susceptibility to infections and allergic disease. Such effects may depend on age at vaccination, and a delay in pertussis vaccination has been linked to reduced risk of allergic disease. We aimed to test the hypothesis that delay in vaccines containing diphtheria-tetanus-acellular pertussis (DTaP) is associated with reduced risk of food allergy and other allergic diseases., Methods: HealthNuts is a population-based cohort in Melbourne, Australia. Twelve-month-old infants were skin prick-tested to common food allergens, and sensitized infants were offered oral food challenges to determine food allergy status. In this data linkage study, vaccination data for children in the HealthNuts cohort were obtained from the Australian Childhood Immunisation Register. Associations were examined between age at the first dose of DTaP and allergic disease., Results: Of 4433 children, 109 (2.5%) received the first dose of DTaP one month late (delayed DTaP). Overall, delayed DTaP was not associated with primary outcomes of food allergy (adjusted odds ratio (aOR) 0.77; 95% CI: 0.36-1.62, P = 0.49) or atopic sensitization (aOR: 0.66; 95% CI: 0.35-1.24, P = 0.19). Amongst secondary outcomes, delayed DTaP was associated with reduced eczema (aOR: 0.57; 95% CI: 0.34-0.97, P = 0.04) and reduced use of eczema medication (aOR: 0.45; 95% CI: 0.24-0.83, P = 0.01)., Conclusions: There was no overall association between delayed DTaP and food allergy; however, children with delayed DTaP had less eczema and less use of eczema medication. Timing of routine infant immunizations may affect susceptibility to allergic disease., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: There is growing evidence for an increase in food allergies. The question of whether early life food sensitization, a primary step in food allergies, leads to other allergic disease is a controversial but important issue. Birth cohorts are an ideal design to answer this question., Objectives: We aimed to systematically investigate and meta-analyse the evidence for associations between early food sensitization and allergic disease in birth cohorts., Methods: MEDLINE and SCOPUS databases were searched for birth cohorts that have investigated the association between food sensitization in the first 2 years and subsequent wheeze/asthma, eczema and/or allergic rhinitis. We performed meta-analyses using random-effects models to obtain pooled estimates, stratified by age group., Results: The search yielded fifteen original articles representing thirteen cohorts. Early life food sensitization was associated with an increased risk of infantile eczema, childhood wheeze/asthma, eczema and allergic rhinitis and young adult asthma. Meta-analyses demonstrated that early life food sensitization is related to an increased risk of wheeze/asthma (pooled OR 2.9; 95% CI 2.0-4.0), eczema (pooled OR 2.7; 95% CI 1.7-4.4) and allergic rhinitis (pooled OR 3.1; 95% CI 1.9-4.9) from 4 to 8 years., Conclusion: Food sensitization in the first 2 years of life can identify children at high risk of subsequent allergic disease who may benefit from early life preventive strategies. However, due to potential residual confounding in the majority of studies combined with lack of follow-up into adolescence and adulthood, further research is needed., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Asthma is a major public health issue. The co-occurrence of the high prevalence of asthma and vitamin D deficiency documented globally in recent decades has prompted several investigations into a possible association between the two conditions. The objective of this paper was to synthesize the evidence from studies that have measured the association between serum vitamin D and asthma incidence, prevalence, severity and exacerbations. A systematic search of the literature was performed in PubMed, and the available evidence was summarized both qualitatively and by meta-analysis. Only English language, observational studies measuring serum levels of 25(OH)D as the exposure were included, as this is the most robust measure of vitamin D levels. The search identified 23 manuscripts: two case-control, 12 cohort and nine cross-sectional studies. Collectively, the evidence suggests that higher serum levels of 25(OH)D are associated with a reduced risk of asthma exacerbations, but there was little evidence to suggest an association with asthma incidence, prevalence or severity. A significant amount of heterogeneity between study methodology and results restricted the scope for meta-analysis. These results suggest that vitamin D supplementation may be effective for the prevention of asthma exacerbations, but the findings need to be confirmed by clinical trials., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The impact of early childhood traffic-related air pollution (TRAP) exposure on development of asthma and allergies remains unclear. Birth cohort studies are the best available study design to answer this question, but the evidence from such studies has not been synthesized to date. We conducted a systematic review and meta-analyses of published birth cohort studies to understand the association between early childhood TRAP exposure, and subsequent asthma, allergies and sensitization. Increased longitudinal childhood exposure to PM2.5 and black carbon was associated with increasing risk of subsequent asthma in childhood (PM2.5 : OR 1.14, 95%CI 1.00 to 1.30 per 2 μg/m(3) and black carbon: OR 1.20, 95%CI 1.05 to 1.38 per 1 × 10(-5) m(-1) ). Also, early childhood exposure to TRAP was associated with development of asthma across childhood up to 12 years of age. The magnitude of these associations increased with age, and the pattern was prominent for PM2.5 . Increasing exposure to PM2.5 was associated with sensitization to both aero- and food allergens. There was some evidence that TRAP was associated with eczema and hay fever. In summary, exposure to TRAP was related to asthma and allergic diseases. However, the substantial variability across studies warrants long-term birth cohort studies with regular repeated follow-ups to confirm these findings., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Asthma and allergy may develop as a result of interactions between environmental factors and the genetic characteristics of an individual. This review aims to summarize the available evidence for, and potential effects of, an interaction between polymorphisms of the CD14 gene and exposure to microbes on the risk of asthma and allergic diseases. We searched PubMed, MEDLINE and Global Health databases, finding 12 articles which met inclusion criteria. Most studies reported a significant interaction between CD14 polymorphisms and microbial exposure. When stratified by age at microbial exposure (early life vs adult life), there was evidence of a protective effect of gene-environment interaction against atopy in children, but not adults. We also found different effects of interaction depending on the type of microbial exposures. There was no strong evidence for asthma and eczema. Future studies should consider a three-way interaction between CD14 gene polymorphisms, microbial exposures and the age of exposure., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Atopic dermatitis (AD) has become a significant public health problem because of increasing prevalence, together with increasing evidence that it may progress to other allergic phenotypes. While it is now acknowledged that AD commonly precedes other allergic diseases, a link termed 'the atopic march', debate continues as to whether this represents a causal relationship. An alternative hypothesis is that this association may be related to confounding by familial factors or phenotypes that comanifest, such as early-life wheeze and sensitization. However, there is increasing evidence from longitudinal studies suggesting that the association between AD and other allergies is independent of confounding by comanifest allergic phenotypes. The hypotheses on plausible biological mechanisms for the atopic march focus on defective skin barrier function and overexpression of inflammatory mediators released by the skin affected by AD (including thymic stromal lymphopoietin). Both human and animal studies have provided evidence supporting these potential biological mechanisms. Evidence from prevention trials is now critical to establishing a causal nature of the atopic march. An emerging area of research is investigation into environmental modifiers of the atopic march. Such information will assist in identifying secondary prevention strategies to arrest the atopic march. Despite much research into the aetiology of allergies, little progress has been made in identifying effective strategies to reduce the burden of allergic conditions. In this context, the atopic march remains a promising area of investigation., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Although egg allergy is the most common food allergy in infants and young children, risk factors for egg allergy remain largely unknown. This study examined the relationship between environmental and demographic factors and egg allergy in a population-based infant cohort., Methods: In a study of 5276 infants (HealthNuts), infants underwent skin prick testing (SPT) to egg white at 12 months of age. Questionnaire data on relevant exposures were obtained. 699/873 (80%) infants eligible for oral food challenge (detectable wheal on SPT) attended for formal assessment of egg allergy status; 453 had confirmed egg allergy (positive challenge and SPT ≥ 2 mm). Associations between environmental and demographic factors and egg allergy were investigated using multivariable logistic regression., Results: Children with older siblings and those with a pet dog at home were less likely to develop egg allergy by 1 year of age (adjusted OR [aOR], 0.72; 95% CI, 0.62, 0.83 per sibling; and aOR, 0.72; 95% CI, 0.52, 0.99, respectively). Caesarean section delivery, antibiotic use in infancy, childcare attendance and maternal age were not associated with egg allergy. History of allergic disease in an immediate family member and having parents born in East Asia were strong risk factors for infantile egg allergy (aOR, 1.82; 95% CI, 1.40, 2.36; and aOR, 3.30; 95% CI, 2.45, 4.45, respectively)., Conclusions: Exposure in the first year of life to siblings and dogs may decrease the risk of subsequent egg allergy. Infants with a family history of allergy and those with parents born in East Asia are at increased risk of egg allergy., (© 2012 John Wiley & Sons A/S.)