SEASONAL INFLUENCES ON THE RESULTS OF SPE CIFIC INTRANASAL PROVOCATION TESTS IN BIRCH POLLEN ALLERGIC RHINITIS

Background: The intranasal allergen Provocation test (INT) is the stan dard procedure to verify the effect of an allergen when a nasal allerg y is suspected. It may be especially useful if results from skin tests or in vitro tests conflict with those from the history. In the clinic al and research setting, INT may be used to study the efficacy of diff erent treatment modalities such as pharmacotherapy or immunotherapy. T he technique of INT has not been well standardized in the past. Variat ions exist in planning the optimum time for testing, especially in sea sonal allergies. Methods: We examined influences of different test dat es with regard to the pollen season on the result of INT. A total of 1 9 patients (eight females, 11 males, aged 26.1 +/- 4.8 years) with a h istory of at least two years of allergic rhinitis to birch pollen, pos itive skin pride test, and RAST (greater than or equal to CAP class II ) to birch pollen. INT was performed during the winter period after ap proximately six months without natural pollen exposition (V1), during the birch pollen season (V2) and six weeks after the birch pollen seas on (V3). Allergens were applied using a pump spray (0.1 ml) in concent rations of 10, 50, 100, 500, 1000, 5000, 10000, 50000, and 100000 SQ u nits per ml (SQ/ml). Results: The threshold concentrations were signif icantly lower at VZ (100 SQ/ml) and V3 (500 SQ/ml) if compared to V1 ( 1000 SQ/ml). Conclusions: Seasonal influences should be taken into acc ount when performing INT in birch pollen allergy.