There are increasing cases of wheat dependent exercise-induced anaphylaxis (WDEIA) with transcutaneous or transmucosal sensitization. Hydrolyzed wheat included in a certain brand of soap was identified as a cause of sensitization. The useful clues to detect this disorder consist of the patient's past usage of a soap containing hydrolyzed wheat, the appearance of cutaneous or mucosal symptoms after the intake of wheat or washing with this soap, and a high level of specific IgE for wheat gluten. Because hydrolyzed wheat is used as an additive in a wide variety of cosmetics, we should pay careful attention to the ingredients of cosmetics when observing WDEIA.