Occupational asthma caused by allergy to pigs' urine.

Occupational asthma caused by allergy to pigs' urine We report a case of asthma due to occupational exposure to pigs.The cause of the symptoms was exposure to the urine of the animals.This was proved by provoking acute asthma with an inhalation challenge of an extract of pigs' urine at a concentration of 1 g/l.On a second occasion this asthmatic response was blocked by prior treatment with 40 mg sodium cromoglycate (Intal).The patient's serum contained specific IgE antibody to the urine extract which was not found in unexposed controls.