A dermatitis of unknown etiology has occurred among about 60 residents working in paddy fields in a rural district of Hyogo Prefecture, located in the side of Seto inland sea (Takasago City).
The dermatitis had been brought about from June, 1981 to August, 1981 after rice-planting and weeding were done, which was characterized by erytemato-papulo-vesicular eruptions with severe itching, mostly during 5 to 15 days. The chief complains and symptoms were obtained on the body parts exposed to paddy field water, especially back of hands, fingers, wrist-joints and lower parts of legs.
The results of questionaries in the patients, clinical observations and seroepidemiological survey by indirect fluorescent antibody method in the use of Schistosoma mansoni cercariae as an antigen, seemed that the dermatitis was due to the invasion of cercariae of anavian schistosome.
The surveillance for snail intermediate hosts has been performed in the fields where the dermatitis occurred. Up to date the cercariae causing the dermatitis has not been clarified yet.
The etiological survey of cercariae from the fresh water snails is proceeding under survey.