A 35-year-old Japanese man visited our hospital with a 2-year history of skin lesions affecting his palms and soles. The palmar lesions comprised diffuse papillomatous hyperkeratotic and macerative reddish skin eruptions (fig 1A). In addition, he had warty-like plaques of 4.5 cm in diameter on his right sole (fig 1B). Upon his initial visit, he did not report any other symptoms such as chills or malaise. These unusual and severe hyperkeratotic lesions did not fit any typical known skin disease such as verruca, Reiter’s syndrome and so on.