Castor bean allergy among workers in the felt industry.

We describe occupational allergy to castor bean in workers in a felt manufacturing plant. Twenty-six (37%) of the workers complained they were affected by the felt and were examined by us. Of these, 12 were considered to have occupational allergy. These 12 subjects had raised specific IgE levels to both felt and castor bean extracts. In addition, three subjects without occupational allergy had raised specific IgE. The presence of castor bean allergens in the felt was suggested by the correlation between the RAST scores to the felt and castor bean and confirmed by RAST inhibition experiments. The RAST results correlated well with the results of skin prick tests to felt and castor bean extracts. In addition it was found that atopy did not predispose the workers to castor bean allergy.