Asthma in merchant seamen and laboratory workers caused by allergy to castor beans: analysis of allergens.

Three merchant seamen and two laboratory workers who developed allergic symptoms following exposure to castor beans have been investigated. Bronchial-provocation testing with castor beans in the merchant seamen demonstrated a late reaction in two. Specific IgE against whole castor-bean extract and ricin, ricinus agglutinin and dericinated extracts of castor bean were found in the patients' sera using radioallergosorbent tests (RAST). RAST inhibition, toxocological and haemagglutination tests suggest that the ricin and dericinated extracts contain distinct allergens.