By Gary M. White, MD

Unna–Thost disease

Unna–Thost disease is characterized by a uniformly thick keratoderma covering the palms and soles without involvement of the dorsal hands or feet.


Both palms and soles are diffusely hyperkeratotic. Often, there is an erythematous rim of demarcation on the lateral palms and soles.

Epidermolytic PPK can present similarly to Unna-Thost disease. Differentiation can be made histopathologically, with the finding of epidermolysis in epidermolytic PPK (see epidermolytic hyperkeratosis).


The patient may be treated with various keratolytic agents topically. 40% urea cream (OTC) is excellent but may irritate normal skin. Oral retinoids, e.g. acitretin 25 mg/day, will usually thin the condition, but bothersome side effects may limit its use.


BMJ Case Reports 2012; doi:10.1136/bcr-2012-006443


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