Acquired perforating dermatosis in renal and diabetic patients
(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)