Castor bean allergy in the upholstery department of a furniture factory.

In this study, undertaken to identify the cause of allergy in several upholstery workers in a furniture factory, the workers were handling several different materials, including glue, silicone spray, upholstery fabrics, and felt. Radio-allergo-sorbent test (RAST) assays showed that sera from sensitised workers contained specific IgE towards the felt; however, further investigations using RAST showed that the allergen was not the felt itself but a contaminant of the felt. The felt was manufactured from sacks, some of which had been used to store castor beans. The sera with raised IgE to the felt also had raised IgE to the castor bean extract. By means of RAST inhibition we confirmed that castor bean allergens in the felt were solely responsible for the raised IgE in the sera. The in-vitro RAST results were found to correlate well with the in-vivo pick tests and clinical symptoms.