Hypersensitivity to food in infants exclusively breastfed - an analysis of the allergy tests' results and the most common food allergens

Introduction
The incidence of adverse reactions induced by food proteins in infants exclusively breastfed is poorly understood. The predominant view is that in the pathogenesis of hypersensitivity to food, IgE-mediated mechanisms prevail; the most common food allergen is cow's milk protein. Aim: The aim of the study was to determine the prevalence of hypersensitivity to food in infants exclusively breastfed with symptoms suggestive of hypersensitivity to food and to identify the most common food allergens responsible for hypersensitivity in IgE-mediated and non-IgE-mediated mechanisms.

Patients and Methods
The study involved 106 infants exclusively breastfed up to 6 months of age, in whom allergy tests were performed due to atopic eczema and/or symptoms from gastrointestinal tract. All patients underwent testing for IgE-mediated and non-IgE-mediated allergy.

Results
Non-IgE-mediated reactions dominated in breast-fed infants with positive allergy tests results. Only positive results of APT were found in 68.9% (n = 73) of patients. IgE-mediated sensitization was found in 3.8% of children (n = 4), mixed type of hypersensitivity affected 6.6% (n = 7) of infants. It has been found that in the group of children with positive sIgE panel (n = 11), allergy to cow's milk protein fractions (n = 9) was most frequent. The most common allergens responsible for non-IgE-mediated hypersensitivity in the study infants were egg yolk (55.7% children; n = 59), then egg white (51.9%, n = 55), cow's milk (33.0%; n = 35), wheat flour (27.4%, n = 29) and soybeans (26.0%, n = 28).

Conclusion
On the basis of own research results, it can be assumed that non-IgE-mediated hypersensitivity to food dominates in infants exclusively breastfed, and the most common food allergen responsible for the clinical response is hen's egg, then cow's milk and wheat.