Abstract
We treated a 57-year-old man with allergic parotitis caused by onion. For years, the patient had experienced episodes of recurrent swelling of the parotid gland, and presented an anaphylactic reaction with parotid gland swelling, urticaria of the palms and dyspnea after eating a curry that contained onion. CT revealed no abnormalities other than the swelling of the parotid glands and the dilation of the main salivary duct. The saliva from the parotid gland was clear and a large number of eosinophils were observed on saliva smears. Recurrent parotitis in association with allergy is known as sialodochitis fibrinosa and is defined by recurrent salivary gland swelling with eosinophil-rich mucus plugs from the salivary duct. Our case did not meet this definition ; we therefore diagnosed the condition as allergic parotitis. IgE antibody tests were positive for onion, dermatophagoides pteronyssinus and Japanese cedar pollen. An onion tolerance test showed an allergic reaction in the parotid glands, we concluded that his allergic parotitis was caused by onion. The patient has remained in a good condition by avoiding onion and taking antihistamines as needed. Although cases of food-dependent allergic parotitis have been reported, there are very few cases in which the allergen can be identified.
