Tacalcitol in the treatment of acquired perforating collagenosis.

Acquired perforating collagenosis (APC) is a rare perforating dermatosis characterized by transepidermal collagen elimination. We describe a 65-year-old patient, with long-standing type 2 diabetes mellitus and a 2-year history of itchy hyperkeratotic nodules situated on the back, who was subsequently diagnosed with APC. Treatment included topical corticosteroids and antihistamines, without improvement of the lesions.