Methodological aspects of nasal allergen challenges based on a three-year tree pollen immunotherapy study.

During 3 years of immunotherapy with tree pollen extracts, 31 patients were provoked annually. Changes in nasal reactivity were followed by registration of expiratory nasal peak flow, number of sneezes, and amount of secretion. The reproducibility of the peak flow measurements was studied. The results from all three parameters were used to form a total nasal provocation score which, better than each parameter separately, could demonstrate the variation in sensitivity. Provocation with an allergen concentration of 1 HEP was the most effective means of showing changes in specific sensitivity of nasal mucosa.