Unna-Thost-type palmoplantar keratoderma. A case report.

Unna-Thost keratoderma is an autosomal dominant inherited disorder of keratinization, with mutation in Keratin 1 gene. The eponym refers specifically to nonepidermolytic keratoderma, although the original Thost family is now known to have had epidermolytic keratoderma. The condition usually presents in the first few months of life and is usually obvious by the age of 4 years. It rarely appears in the third decade. An even, thick, yellow hyperkeratosis occurs over the whole of the foot, starting on the heel and anterior arch, spreading later to the palms with a sharp demarcation at the wrist, sparing the dorsal surfaces of hand and feet (nontransgredient). The margins show a reddish border with a waxy consistency. Hyperhidrosis is common and dermatophytic infections and pitted keratolysis are frequent but there is no systemic involvement. Diagnosis is mainly clinical and prognosis is poor as condition persists for a lifetime. Various treatment modalities have been tried for the condition with unsatisfactory results and it is paramount to monitor the results of treatment by liver function test, kidney function test and lipid profile in addition to clinical examination. CASE REPORT