Immunoglobulin-E (IgE) -dependent food allergy is diagnosed by "allergic reactions induced by foods" and "presence of antigen-specific IgE antibodies". If the causative food cannot be identified, the diagnosis of food allergy is confirmed by an oral food challenge (OFC). It is necessary to select the medical institution and OFC method to improve the safety of OFC. If it is difficult to perform OFC at the respective facility, the physician needs to refer the patient to a medical institution that can perform OFC immediately.

However, there are still cases in which patients are instructed to avoid food without a correct diagnosis. In cases of infantile atopic dermatitis, we experienced cases in which the patients were instructed to avoid multiple foods due to positive antigen-specific IgE testing only without treatment of eczema. There have also been cases of people who were diagnosed with food allergies in infancy and continued to avoid the causative food without undergoing OFC until adolescence. We have also experienced cases in which patients were instructed to avoid foods on which they have incorrect knowledge of cross-reactivities, such as peanuts, tree nuts, and crustaceans. In this article, we aimed to describe the correct diagnosis and evaluation of food allergy in childhood and contribute to the improvement of the quality of food allergy treatment.