Background: The natural history of food allergy in childhood may be affected by many temporal, genetic and environmental factors. Current data on the chances of resolution of egg allergy (EA) is an important factor in counselling of affected children and families. Our study aimed to evaluate the natural progression from allergy to tolerance of EA children in our community.
Methods: As part of a larger case control study, we included EA children, diagnosed and followed in community allergy practices, following recommendations for strict avoidance of egg containing foods. Data was collected from electronic medical records and telephone questionnaires. Analysis was performed using non-parametric Kaplan-Meier and the proportional hazard Cox regression model.
Results: 58 egg allergic children, 35(61%) males, median age at EA diagnosis 10 months (7-12 inter quartile range), were followed to a median age of 65 months (45-104). The initial allergic reaction as described by the parents was anaphylactic (2 or more system involvement - AnReac) in 20 (35%) of patients, however only 3 were treated appropriately with IM epinephrine! At last follow-up, 60% of children were able to tolerate eggs in all cooked forms, the median age at EA resolution calculated via the COX regression model was 54 months (95% CI 39-69 months). However, only 35% of children with a history of an AnReac showed EA resolution in the period of follow-up, compared to 72% of children without an AnReac (p<0.02). The median age at resolution of EA in children with AnReac was 85 months Vs 44 months in children without AnReac. The odds ratio for EA persistence in the AnReac group was 2.6 (95% 1.2-6.1, p=0.027).
