Antigen-induced enhancement of bronchial reactivity

Bronchial hyperreactivity as determined by the airway response to methacholine was evaluated pre- and post-antigen challenge in three patients with specific antigen sensitivity. No significant change in pulmonary function was noticed after inhalation of antigen alone. However, transient but significant increase in methacholine responsiveness followed the antigen challenge. The studies indicate a need for a nonspecific inhalation challenge following a negative antigen challenge when clinically indicated.