Finger dermatitis among perilla workers have been reported since 1970 in Japan. The agricultural chemicals used for perilla culture and the allergic effects of the perilla itself are discussed as for the causative factors of the dermatitis.
In this report, epidemiological survey and dermatological examination were carried out, with special concern for the prevalence of hazards of each fingers of the workers in relation to their work process, especially picking perilla leaves. Subjects were all of 152 workers who engaged in perilla culture in 2 area in Nankoku, Kochi Prefecture. And the skin patch testing for 32 workers (17 ones with dermatitis and 15 ones without dermatitis) and 20 controls was done using samples of the leaves cultivated without agricultural chemicals for more than 3 weeks and perilla oil extracted from them.
Results were as follows.
1. Skin hazards of the fingers, such as erosion, fissure, desquamation, thickening or bleeding were observed among about half of the workers.
2. The hazards were more frequently observed among the workers whose working hours for perilla culture and picking perilla leaves were longer.
3. The hazards were more frequently observed in the fingers touching the reverse sides of the leaves which had the secreting glands than in those touching the surface sides, on which might be contaminated by agricultural chemicals.
4. The perilla oil acted as the irritating substance for almost all of the examinee, and the skin patch testing demonstrated that both the perilla leaves and their oil caused allergic reactions to the workers with dermatitis.
5. It was considered that the perilla leaves and their oil had played an important role of a cause of the dermatitis among the perilla workers.