[Comparison of the prevalence of symptoms and medical histories between Yusho patients and healthy controls].

Yusho disease was first reported in October 1968 in western Japan. Although a previous survey revealed that Yusho patients have suffered from various symptoms for 40 years after the outbreak of Yusho, some symptoms could be caused by aging. Therefore, we compared the prevalence of symptoms and medical histories (symptoms or patient-reported diseases) between Yusho patients and healthy controls to demonstrate the effects of Yusho on health conditions. We conducted a survey of healthy controls who had already registered to a survey company and created a dataset of symptoms and medical histories. We then merged the healthy control data with the Yusho survey data obtained from The Ministry of Health, Labour, and Welfare of Japan. Statistical analyses were performed using a chi-square analysis for the incidence of symptoms. Symptoms included in the major diagnostic criteria for Yusho, such as pigmentation and acneform eruption, were expectedly higher in the Yusho patients than in the healthy individuals. Symptoms that could be caused by aging, such as general fatigue, arthralgia, and numbness in the extremities, were also significantly higher in the Yusho patients after adjustment for age, indicating the possibility that Yusho may cause various systemic symptoms and diseases.