An allergen exposure system includes a mixing chamber, delimited by walls and distinct from the air inlet duct and from the exposure room in which the patients are situated. A mixing between a stream of allergen particles from an allergen injection device and a flow of air devoid of allergens which has passed through a filtration device, occurs through a phenomenon of microturbulence in this mixing chamber which forms a widening with respect to the air inlet duct and makes it possible to obtain a flow of air laden with allergen particles which is injected into the exposure room through at least one diffusion outlet so that it can be inhaled by the patients. This invention is of benefit to medical and pharmaceutical research in the field of allergy study.
