Background: The prevalence of allergic disorders is on the rise, affecting about 10% of the population. In this retrospective cohort, we investigated prevalence of allergic disorders, associated risk factors, and the outcome of food allergies.
Material and methods: We analyzed data from birth cohorts of two university hospitals' well-child outpatient clinics. Factors related to onset and type of allergic diseases were assessed from demographic, socioeconomic, and clinical data.
Results: Analyses were performed on 949 (431F/518M) infants at a mean current age of 28±6 months. Any allergic disease was established among 177 cases (22%); atopic dermatitis in 123 (12.8%), respiratory allergies in 55 (5.7%), and food allergy in 41 (4.3%). The risk for allergic disorders was found to be significantly increased for male gender (OR: 2.31, 95% CI; 1.54-3.46), and positive parental atopy (OR: 1.94, 95% CI; 1.31-2.86). The risk of food allergies was significantly higher in the male gender (OR: 2.47, 95% CI; 1.21-5.02), who consumed egg-white between 6 and 12 months (OR: 2.34, 95% CI; 1.22-4.48), and who were formula-fed before 6 months (OR: 2.16, 95% CI; 1.14-4.10). We found no significant association between the rate of food allergy outgrowth or food induced-anaphylaxis with regards to the timing of introducing egg-white into the diet.
Conclusions: Although the introduction of egg-white into infant diet at 6-12 months of life appeared as an independent risk for any food allergy, none of the patients developed anaphylaxis. Age at symptom onset and outgrowing food allergy were similar compared to those introduced egg-white after 12 months. We recommend promoting exclusive breastfeeding during the first 6 months of life, and avoidance of prolonged restrictive diets for children with food allergy.
Keywords: breastfeeding; egg white; food allergy; infant; risk factors.