IgE-Mediated Cow's Milk Allergy in Iranian Infants and Children: Predictive Factors of Early Tolerance

Background: The majority of infants and children with cow's milk allergy will grow out of their allergy after a few years. The aim of this study was to identify the natural course of cow's milk allergy in infants and children during a follow-up of 18 months and also the predictive factors for its outgrowing. Methods: This prospective cross-sectional study included infants and children with IgE-mediated cow's milk allergy. Demographic data, clinical manifestations and probable predictive factors were recorded. Skin prick tests were done with commercial extracts of cow's milk, egg, fish, nuts and wheat on arrival. These infants and children were followed for 18 months and resolution was established by successful ingestion of cow's milk. The collected data were analyzed using SPSS version 22.0. Descriptive statistics, student's t-test or Mann-Whitney U-test and Chi-square test were used; a P < 0.05 was considered statistically significant. Results: Forty-nine infants and children (33 boys and 16 girls) with IgE-mediated cow's milk allergy presentation ranged in age from 3.5 to 48 months with a mean of 17.5 +/- 11.7 months enrolled in this study. Skin was the most common site of involvement, followed by gastrointestinal system and respiratory tract. Twenty-three (46%) infants and children developed tolerance to cow's milk during a follow-up of 18 months. There was a significant relationship between parental allergy and atopic dermatitis with the chance of tolerance of cow's milk. Conclusions: Our findings showed that about one half of the infants and children with IgE-mediated cow's milk allergy grew out of it over 18 months of follow-up (mean age 2 years). The follow-up of patients with cow's milk allergy is important in appropriate timing of re-introduction of cow's milk to the diet; atopic dermatitis and parental allergy can predict this outcome.