Abstract
Vomiting, diarrhea, bloody stool, and failure to thrive are the typical symptoms observed in food allergy patients during infancy. Eosinophil infiltration is the common findings especially with patients with bloody stool. “Confirming bloody stool after milk ingestion with eosinophilia” is often considered as an allergic reaction because it is the adverse events after the specific food ingestion induced by immune cells. However, it is not easy to prove the antigen specificity because milk is the only antigen infants can intake during early infancy. Antigen specificity should always be re-evaluated even though the patient is positive for ALST. How are the eosinophils infiltrated? Although the elevation of serum IL-5 or ECP levels sometimes confirmed, it is not easy to prove it as an allergic reaction induced by a specific antigen. Since there is no IgA in early infancy, we consider that eosinophils may be protecting host from pathogens’ invasion instead of IgA. Further investigation is also necessary to find the relationship between eosinophil infiltration and intestinal flora.
