Many treatments have been proposed for acquired perforating dermatosis (APD), with varying success. In general, treatment is unsatisfactory and definitive resolution of existing lesions is difficult to achieve.
A 65-year-old woman presented with a 6-month history of pruritic, hyperpigmented papules with central, hyperkeratotic plugs on her bilateral lower extremities (Figure 1A). There were no papules on her trunk, head, upper extremities, volar surfaces, or mucous membranes. Her medical history was significant for chronic renal failure treated for the past 4 years with peritoneal dialysis, a 30-year history of insulin-dependent diabetes mellitus, hypercholesterolemia, hypertension, coronary artery bypass, hypothyroidism, and hyperparathyroidism. There was no family history of similar skin lesions. A biopsy specimen from a lesion on the left leg revealed keratotic plugs filled with laminated orthokeratotic and parakeratotic keratin and debris. Beneath the plug, the epidermis was thinned and the dermis showed a neutrophilic infiltrate and foci of fibrosis (Figure 2A). Trichrome stain showed rare focal collagen extruding through the base. The surrounding skin showed features of lichen simplex chronicus. The clinical and histopathologic features supported the diagnosis of an acquired perforating disorder associated with renal disease.
Wong J, Phelps R, Levitt J. Treatment of Acquired Perforating Dermatosis With Cantharidin. Arch Dermatol. 2012;148(2):160-162. doi:10.1001/archdermatol.2011.350