Urticarial reaction following the inhalation of nicotine in tobacco smoke.

We report a patient with recurrent generalized itching and urticaria due to inhalation of nicotine in tobacco smoke. A skin prick test with nicotine base (1:10 w/v) was negative but an intradermal test with nicotine base (1:100 w/v) was strongly positive. Intradermal tests with nicotine base (1:100 w/v) performed on 10 healthy controls were negative. A provocation test with a nicotine patch showed the same symptoms and signs including generalized itching, weals and flares, and mild dyspnoea, which occurred when he was exposed to tobacco smoke. Nicotine in tobacco smoke can act as an inhalant allergen and induce urticaria in hypersensitive persons.