抄録
Some patients with pollen hypersensitivity have oral allergic reactions to fresh fruits and vegetables. This condition has been termed Oral Allergy Syndrome (OAS). It is a distinctive type of IgE-mediated allergy resulting from direct oral contact with food, and is proposed to be due to cross-reacting allergens in the foods and pollens.
We studied 97 patients (43 male and 54 female patients) with birch pollen allergy (BPA). The diagnosis was confirmed by the clinical symptoms of seasonal rhinitis and the presence of the specific anti-birch IgE antibody by CAP-RAST (a score equal to or greater than 2). The onset of BPA, atopic symptoms and a family history were examined in an interview with each patient. We also asked about oral hypersensitivity to eighteen kinds of fruits and vegetables such as apples, potatos, kiwis, nuts, celery and melon.
The results were as follows:
1) 35% of birch pollen allergic patients had oral symptoms after fruit and vegetable ingestion.
2) The causative foods in OAS, in order of frequency, were apples, peaches, cherries, plums and others. Most patients with OAS showed hypersensitivity to more than two foods (mean value; 3.4 foods).
3) OAS-positive patients had a longer duration of BPA than OAS-negative ones (mean years 9.0 vs 5.7; p<0.025). The OAS was significantly related to the duration of BPA and a previous history of asthma.
4) No difference was observed in mean age or sex between the two groups.
5) The score for specific anti-birch pollen IgE levels was significantly greater in OAS-positive patients than in OAS-negative ones (p<0.0025), whereas no difference was observed in total IgE levels between the two groups.
