Occupational type bronchial provocation tests: testing with soluble antigens by inhalation.

Thirty-seven patients with asthma or alveolitis thought to result from exposure to materials commonly encountered at their work were tested by inhalation of an aerosol of these materials. Twenty-four (65%) developed an immediate asthmatic reaction, which was followed by a non-immediate reaction in 10, of whom six developed the signs and symptoms of alveolitis. Eighteen (76%) patients with asthmatic reactions to test material were prick test positive to that material while only two our of 13 with a negative inhalation test were prick test positive (15%). Precipitating antibody to test material was measured in 23 and was present in nine (39%) of those with positive inhalation tests, and one (12%) of those with negative tests. It was present in five of the six with a reaction in the gas exchanging portions of the lung.