Occupational asthma due to piperazine citrate.

BACKGROUND Piperazine is a secondary heterocyclic amine that may give rise to occupational asthma of uncertain mechanism. METHODS We report on a 42-year-old woman, a process operator in a chemical factory, who developed work-related symptoms of rhinitis and asthma upon exposure to piperazine citrate. She remained symptom free during holidays and days off work. RESULTS Skin prick test with piperazine citrate was positive. Specific inhalation challenge with piperazine citrate at a concentration of 5 mg/m3 for 30 minutes elicited an isolated late asthmatic response. Airway hyperresponsiveness to methacholine significantly increased 3 hours after the piperazine challenge, preceding the late asthmatic response. CONCLUSION This patient had developed occupational asthma caused by piperazine, as confirmed by the specific inhalation challenge test, possibly due to an immunological mechanism.