Accelerated cell-mediated broncho-obstructive reaction to inhaled stepronin: a case report.

We describe the case of a 20-year-old man who developed an obstructive bronchial reaction accompanied by a maculopapular facial rash 8 h after an aerosol treatment with the mucolytic drug stepronin. The results of intradermal and patch testing with stepronin, together with those of bronchial challenge and histologic findings in patch-tested skin, indicate that the patient's reaction involved an accelerated cell-mediated mechanism of hypersensitivity. Bronchial challenges with methacholine demonstrated a transient increase in nonspecific bronchial hyperreactivity.