OCCUPATIONAL TYPE-I ALLERGY TO CHRISTMAS CACTUS (SCHLUMBERGERA)

The study aimed to determine whether occupational contact urticaria an d symptoms of mucous membranes, reported by five workers in a cactus n ursery, were due to IgE-mediated allergy to Schlumbergera cacti. The f ive persons had positive skin prick tests to the plants as is and posi tive histamine-release tests, and in three of them specific IgE to the cacti could be demonstrated by Maxisorp RAST and immunoblotting. Four of the patients were atopic, and the fifth had a positive skin prick test to cat dander, indicating latent atopy Skin prick tests with cact i were negative in most atopic volunteers, and all had negative histam ine-release tests. The results suggest a true IgE-mediated allergy to the cacti, and both genetic predisposition and close contact with the plants at work seem to be important factors in the emergence of this n ew occupational allergy.