A monocentric, double-blind, placebo-controlled, cross-over study conducted outside of the pollen season. The study lasts 3 months for each patient, which includes a screening period, two exposure visits in the Alyatec Environmental Exposure Chamber (EEC) with active or placebo air cleaners, and a follow-up visit.
Patients with early asthmatic reaction during baseline exposure are randomly allocated to one of two sequences: active air cleaners /placebo or placebo/active air cleaners. Randomization is balanced (1:1) between the two sequences. There is a 3-week wash-out period between the two exposures.
