Evaluation of dermatological symptom of Yusho patients in the annual examination in 2005-2007

Yusho is recognized as a poisoning by a mixture of polychlorinated biphenyls (PCBs), dioxins and related compounds. We have continued a follow-up of skin symptoms in patients not only for supporting patients' health but also for understanding the possible prolonged effects of exposure to PCBs and dioxins in humans. We evaluated the severity grades and the skin severity scores of the symptoms who visited the annual examinations of Fukuoka prefecture from 2005 to 2007. Forty years have passed since the Yusho incident, and about 70% of the patients currently present no skin symptoms. In contrast, in about 30% of the patients, characteristic skin symptoms of Yusho, such as pigmentation of skin, black comedones and acneform eruptions, could still be observed. We analyzed statistical correlations between blood levels of PCBs or dioxin and skin severity grades.