Ice pack-induced perniosis: a rare and underrecognized association.

Perniosis, or chilblain, is characterized by skin lesions that occur as an abnormal reaction to exposure to cold and damp conditions. It can present as an idiopathic dermatosis or in association with an underlying connective tissue or autoimmune disease. Differentiation by histopathologic examination is controversial. Herein, we report a unique case of a 73-year-old woman who developed acquired perniosis on the buttocks from the use of ice packs to treat chronic low back pain.