Safety and Repeatability of Bronchial Challenge With Grass-pollen

Background: Specific provocation with inhaled allergens is an established tool in clinical practice and research, supporting the understanding of pathophysiology of allergic asthma, and analysing the efficacy of new therapies. This study examines the repeatability of a bolus-dose inhalative allergen challenge with grass pollen. Method: Forty grass pollen allergics should undergo an incremental-dose grass pollen challenge to calculate their PD20-dose. This calculated dose will be applicated twice to analyse the repeatability of the bolus dose challenge. Before and twenty-four hours after the provocation, exhaled nitric oxid (FeNO) will be determined as a marker of bronchial inflammation.