A case of anaphylaxis caused by enokitake (Flammuuna velutipes) ingestion

Abstract

Enokitake (Flammnlina velutipes, winter mushroom) is a common edible mushroom in Japan. We experienced a case of anaphylaxis after enokitake ingestion. There are no reports describing anaphylaxis caused by the ingestion of this mushroom. Enokitake allergen has also not been reported. We thus attempted to identify enokitake allergen using the patient's serum. The patient was a seventeen-year-old woman who had had no episodes of food allergy and experienced anaphylaxis after the ingestion of sukiyaki (beef, pork, tofu, vegetables, enokitake, etc.). She had previously eaten sukiyaki (the same ingredients) without any symptoms. The result of enokitake skin prick to prick test was positive. Oral food challenge was positive, inducing anaphylaxis. We performed western blotting with enokitake extract and the patient's serum. Three enokitake protein bands (18kDa, 39 kDa, 50kDa) reacted specifically with the patient's IgE.