Common fruits and vegetables were tested as such with the “scratch-chamber” method in 388 patients with various atopic disorders. Of the patients with hypersensitivity to birch pollen, 36% showed immediate positive responses to these natural, fresh materials. Apple, carrot, parsnip and potato elicited reactions more often than, e.g. swede, tomato, onion and parsley. On the basis of clinical data, the relevancy of the results of the skin tests was 80–90%. Both “false positive” and “false negative” responses were seen.
Itching and tingling with or without oedema of the lips, mouth and tongue were the most common complaints after eating raw fruits and vegetables. In addition, laryngeal and abdominal disturbances, rhinitis and hand dermatitis were recorded.
Among patients without allergy to birch pollen, reactions to fruits and vegetables were rare.
The nature of the allergens could not be determined.