Anaphylaxis caused by cross-reactivity of furocoumarins in lemon with orchardgrass.

Fruit-related oral allergy syndrome caused by a pollen antigen in orchard grass (Dactylis glomerata) is well known. However, there are few reports of anaphylaxis caused by orchard grass1 or lemon due to cross reactivity with orchard grass2 and no reports of anaphylaxis induced by photosensitivity. Case. A 34-year-old female nursery worker suffered with allergic rhinitis from May to August since the age of 23 and allergic conjunctivitis from the age of 25. She experienced urticaria due to hypersensitivity several times a year since the age of 20.