Acquired Perforating Dermatoses:
dermatoses are a group of conditions characterized by transepidermal
elimination of dermal material (collagen, elastic tissue or necrotic connective
tissue) (CMAJ). APD is one of the 4 major perforating disorders:
- Reactive perforating collagenosis
(inherited disorder of collagen perforation) - Elastosis perforans serpiginosa (elastic tissue perforation
associated with Down syndrome and Ehler–Danlos syndrome) - Perforating folliculitis (perforation of necrotic material
secondary to local trauma) - Acquired
perforating dermatosis.
Historically there was a lot of overlap in
terminology between these disorders. Acquired perforating dermatosis
classically presents with severely pruritic follicular hyperkeratotic papules,
sometimes umbilicated, on the hair-bearing limbs of adults. Generalized papules
may also be seen. Acquired perforating dermatosis is a chronic disease, usually
associated with diabetes mellitus or renal failure or both. In patients
receiving dialysis, acquired perforating dermatosis occurs in about 10% of
patients. It is also rarely associated with liver disease, malignant disease,
hypothyroidism and HIV. Skin biopsy is required to diagnose APD. This reveals
epidermal invagination or dilated hair follicle with a keratotic plug of
keratin, collagen or elastic fibres and neutrophils. The pathophysiology is not
well understood. Topical and systemic retinoids, topical corticosteroids and
keratolytics, UVB, psoralen and UVA, allopurinol, cryosurgery and photodynamic
therapy have all been considered in the treatment of this disorder.
Image shows: Follicular keratotic papules consistent with acquired perforating dermatosis distributed diffusely over the legs (A) and buttocks (B). Skin biopsy (C) showing a hair follicle with perforation extending into the dermal tissue, which contains a tract of necrotic tissue debris with degenerate elastin fibres. (From CMAJ)
Posted by Andrew Malone
