Case of anaphylaxis caused by ingestion of royal jelly.

Anaphylaxis is a severe form of allergic disease. Royal jelly is widely consumed in Japan, but a few cases of anaphylaxis caused by royal jelly have been reported. We encountered a 26-year-old Japanese woman who developed anaphylaxis after drinking a beverage of crude royal jelly including honey. She had a history of bronchial asthma, allergic rhinitis, allergic conjunctivitis, atopic dermatitis and food allergy (abalone). Prick tests were performed with the beverage of crude royal jelly including honey and with two other beverages including honey. Only the crude royal jelly beverage showed a positive reaction. An oral challenge test with the crude royal jelly beverage was not performed, but a similar test with a beverage including honey caused no symptoms. A positive response to the beverage of crude royal jelly was not observed in normal volunteers. A positive diagnosis of anaphylaxis due to royal jelly was made based on the positive prick test, systemic clinical symptoms and the negative prick tests in healthy volunteers. Moreover, the patient had no symptoms when taking lemon and orange, which were present as essences in the crude royal jelly beverage, and also had no response to honey after anaphylaxis. Increased consumption of royal jelly in health food supplements may increase the incidence of royal jelly-related allergic reactions. Therefore, royal jelly should be considered as a causative allergen in food-induced anaphylaxis.