Prevalence of occupational asthma in silk filatures.

A clinical survey in two silk filatures revealed that 36.2% of the persons engaged in the processing of natural silk were suffering from bronchial asthma, while 16.9% of the total subjects had asthma of occupational origin. Skin prick tests using crude silkworm cocoon and pupal allergen extracts revealed that 28.8% of the subjects were sensitive to the silkworm-derived allergens. IgE antibodies specific to both cocoon and pupal allergens were demonstrable by RAST in the sera of patients with positive skin reactions and occupational asthma.