[Verification of the hygienic hypothesis by evaluating the regional incidence of eosinophilic pustular folliculitis].

Eosinophilic pustular folliculitis (EPF) is a disorder associated with a high expression of interleukin-5 by T helper 2 cells. Treatment involving T helper 1 (Th1) modulation has been shown to be effective. We report that the occurrence of Bowen's disease in the medical care zone of the University of Occupational and Environmental Health in the Kitakyushu industrial area is more frequent in Yahatahigashi-ku, Yahatanishi-ku, and Wakamatsu-ku than in Tobata-ku, Kokurakita-ku, and Kokuraminamiku. We also show that these cases are more common in the regions with steel- and coal-related industries, which is suggestive of a higher rate of Th1 modulation associated with these occupations. Similarly, the incidence of EPF per unit population was found to be high in Tobata-ku and low in Yahatahigashi-ku, which indicates that EPF is a typical disease of hygiene hypothesis.