Yusho, a poisoning caused by rice oil contaminated with polychlorinated biphenyls.

SPORADIC outbreaks of a peculiar skin disease were reported in Fukuoka-Ken (Fukuoka Prefeeture), Japan, in early October 1968. It was charaeterized by sueh symptoms as follicular accentuation, acneform eruption, pigmentation of the skin and nails, and hypersecretion of the Meibomian gland. Staff members of the department of dermatology of the Faculty of Medicine, Kyushu University, Fukuoka, who examined some of the early patients suspected they had chloraene. A possible causal relationship between the disease and ingestion of a certain brand of rice oil was also suspected in view of the distinet familial aggregation of the patients and their common use of the oil (1). This relationship was subsequently proved, and the disease was called Yusho, or rice oil disease. To elarify the cause of the epidemic, a study group headed by Prof. S. Katsuki of the Kyushu University Faculty of Medicine was organized by the staff of that university, the School of Medicine of Kurume University, and local health departments. An epidemiologic study subgroup was set up within the study group on October 19, 1968, which was directed by Kuratsune and also included the other three authors. This subgroup immnediately designed and carried out a series of extensive surveys in close cooperation with the department of hygiene of our faculty of medicine and the departments of public health of the Prefecture of Fukuoka and of the cities of Kitakyushu, Fukuoka, and Ohmuta. The epidemic spread not only over FukuokaKen but also over 20 other prefectures in the western part of Japan. It produced 1,001 patients -502 males and 499 females-according to the latest tabulation by the section of food hygiene, Ministry of Welfare. Although our study of the epidemic was confined to Fukuoka-Ken, and the epidemic proved to be caused by accidentally contaminated oil, we believe that publication of our results will help prevent similar food poisonings. These incidents can occur anywhere in the world if sufficient care is not exercised.