Idiopathic perniosis of the buttocks and thighs - clinical report.

Perniosis manifests as inflammatory cutaneous lesions mostly located on acral skin in association with cold and damp conditions. Perniosis of the thighs is quite uncommon and has been associated in the literature with horse riding (equestrian perniosis) or with other recreational activities with long time exposure to cold and humidity. We report a rare case of perniosis of the buttocks and thighs in a 34-year-old healthy woman without a previous history of horse riding or other high-risk activities. In this case, the use of thin and tight clothes is believed to have been enough for the development of perniosis in this susceptible subject.