Skin Lesions in Dialysis - Part 4

Acquired Perforating Dermatoses:

Perforating 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