HDCN Article Review/Hyperlink

Farrell AM

Acquired perforating dermatosis in renal and diabetic patients

Lancet (Mar) 349:895-896 1997

Dialysis patients are subject to chronic pruritus and a variety of strange skin lesions, among them a condition previously known as hyperkeratosis penetrans, characterized by the appearance and gradual enlargement of pruritic papules which subsequently develop necrotic centers on the trunk and extremities. The disorder has also been found in diabetics, and the pathogenesis is unknown.

In this commentary by Farrell, he first notes the occurrence of similar lesions, called primary "perforating dermatoses" in Kyrle's disease, perforating folliculitis, reactive perforating collagenosis, and in elastosis perforans serpiginosa. To a non-dermatologist, these terms are not helpful. The same condition in renal and diabetic patients is now termed "acquired perforating dermatosis", or APD. The lesions are dome- shaped papules or nodules, 1-10 mm in diameter, with a central crust filled crater. Later on, large cup-shaped plugs are formed in the epidermis. Prevalence of the lesion in dialysis patients has been reported to be 4- 11%, with onset early in the course of renal replacement therapy.

The pathogenesis is still unknown. One view is that the lesion is a foreign body reaction to some consituent of the dermis; perhaps to microcrystals, although this point is controversial. Because the lesion is associated with pruritus, another view is that trauma due to scratching coupled with a poor local blood supply leads to localized dermal necrosis with subsequent extrusion of the dead tissue through the epidemis. Topical retinoids, topical and intradermal steroids, and ultraviolet B light have been tried therapeutically with "some benefit", but there is no therapy that works reliably. (John T. Daugirdas, M.D., University of Illinois at Chicago)