BIRCH POLLINOSIS AND ATOPY CAUSED BY APPLE, PEACH, AND HAZELNUT COMPARISON OF 3 EXTRACTION PROCEDURES WITH 2 APPLE STRAINS

This study aimed, first, to study the prevalence in The Netherlands of atopy caused by apple, peach, and hazelnut in patients with tree poll inosis, and, second, to compare three extraction procedures for skin p rick testing with two different apple strains. Skin prick tests and RA ST were performed on 79 consecutive patients with tree pollinosis. vis iting the department of allergology during spring 1995. In skin prick tests, we used three different extracts (juice, freeze-dried extract, and low-temperature acetone powder extract) of two apple strains, Gold en Delicious and Granny Smith. Case histories for apple, peach, and ha zelnut were positive in 35 (44.3%), 23 (29%), and 35 (44.3%) patients, respectively. More than two-thirds of the patients had symptoms chara cteristic of oral allergy syndrome. Skin prick tests for apple, peach, and hazelnut were positive in 51 (64.6%), 61 (77.2%), and 71 (89.9%) patients, respectively. Granny Smith showed more positive skin reactio ns and a better agreement with clinical history than Golden Delicious, and juice was superior to the two other extraction procedures for bot h apple strains. RAST for apple, peach, and hazelnut was positive in 5 3 (68.8%), 13 (16.9%), and 31 (40.3%) patients, respectively. Concorda nce between skin prick test and case history was found in 77%, 52%, an d 54%, for apple, peach, and hazelnut, respectively. We found a high p ercentage of concurrence of clinical allergy to birch pollen and apple , peach, and hazelnut, confirmed by both skin prick testing and RAST. Approximately half of these patients had symptoms (especially oral all ergy syndrome) after eating these products. We also found an easy extr action procedure (juice extract) suitable for apple skin prick testing , superior even to freeze-dried extraction or the low-temperature acet one powder technique.