(BMJ)—A 69-yo woman w/ type 2 DM presented w/ a 9-mo hx of a pruritic eruption on her back and buttocks, w/ no relief from betamethasone/fusidic acid cream. Exam: multiple discrete red, crateriform nodules and plaques w/ central black crust. Bx confirmed the dx. What is it?
Elastosis perforans serpiginosa
Prurigo nodularis
Acquired perforating dermatosis
Granuloma annulare
Flegel disease
You are correct. Bx confirmed the clinical impression of acquired perforating dermatosis, a perforating d/o strongly assoc w/ DM and chronic renal dz. Pruritus is a prominent feature of both conditions, and injury to the skin through scratching is thought to be implicated in the pathogenesis. Tx includes topical and oral steroids, abx, retinoids, MTX, and phototherapy. This pt had an excellent response to narrowband ultraviolet B radiation.

BMJ 2017;359:j4839