This 43-year-old man withg a history of Human Immunodeficiency Virus infection, chronic renal failure requiring dialysis, and diabetes developed an eruptive pruritic eruption on his extremities, back, and head 2 years ago. The lesions usually begin as small dark bumps which gow in size and develop small “crystals” in the center which eventually fall out leaving a small hole in the skin. On examination most of the lesions were located on the extensor surfaces of the arms and legs but some were scattered on the trunk, scalp, and forehead. Histopathology was read initially as a perforating collagenosis, but review showed a keratinaceous plug without diagnostic features of a perforating disorder.Perforating disorders comprise a collection of skin disease that are papulonodular in nature and have the hallmark feature of a central hyperkeratotic plug through which dermal components are eliminated. Specific perforating disorders include elastosis perforans serpiginosa, reactive perforating collagenosis, and acquired perforating dermatosis (APD), which has been used as a synonym for or a category which encompasses those cases designated as Kyrle’s disease.
Kyrle’s disease (hyperkeratosis follicularis et parafollicularis in cutem penetrans) was originally described in 1916 in a diabetic woman with generalized hyperkeratotic nodules1. There is some controversy in the literature in regards to classification of the perforating disorders, as there is a great deal of overlap, clinically and histologically. We use the diagnosis of APD to refer to a perforating skin disease that presents in adulthood in association with diabetes mellitus or renal failure.
APD is relatively common, with a reported incidence of 4.5 to 11% of those on chronic hemodialysis2,3. There is no sex or racial predilection. The pathogenesis is not well understood but it is theorized that pruritus, often found in uremic patients, leads to excessive scratching of the skin. In the setting of diabetic vasculopathy this could lead to dermal necrosis, which is then eliminated through the epidermis (can include both elastin and collagen)2. Another hypothesis is that there is an “uncoupling of epidermal proliferation and differentiation,” with keratinization occurring faster that new cell production. Keratinization of the basal layer incites a dermal inflammatory reaction, leading to the classic papulonodule with a hyperkeratotic plug4.
Clinically the lesions start as small pin-head size papules and can grow to close to one centimeter. There is a predilection for the extensor surfaces of the legs, and the arms, trunk, head and neck can be involved. There are reports of koebnerization. The duration of these lesions ranges from 4 months to 43 years4. APD has been reported to develop in patients with lymphoma, sclerosing cholangitis, congestive heart failure, and HIV, but many of these patients also had concurrent renal failure or diabetes2-5. Treatment includes oral retinoids, phototherapy (PUVA and UVB), and anecdotal evidence has shown improvement with topical, intralesional, oral steroids, topical retinoids and salicylic acid, among others.
References:
1. Kyrle J. Hyperkeratosis follicularis et parafollicularis in cutem penetrans. Arch Dermatol Syphilol 1916;123:466-93.
2. Morton CA, Henderson IS, Jones MC, Lowe JG. Acquired perforating dermatosis in a British dialysis population. Br J Dermatol. 1996;135:671-77.
3. Hood A, Hardegen GL, Zarate AR et al. Kyrle’s disease in patients with chronic renal failure. Arch Dermatol. 1982;118:85-8.
4. Patterson JW. The perforating disorders. J Am Acad Dermatol. 1984;10:561-81.
5. Skiba G, Milkiewicz P, Mutimer D, et al. Successful treatment of acquired perforating dermatosis with rifampicin in an Asian patient with sclerosing cholangitis. Liver. 1999;19(2):160-3.
Description
multiple 0.5 cm to 1 cm hyperpigmented papules with a central hyperkeratotic plug
