Diffuse palmoplantar keratoderma
Unna-Thost syndrome, Tylosis
Diffuse palmoplantar keratoderma is an autosomal dominant condition consisting of an even, smooth plate of hyperkeratotic yellowish skin covering the palms and soles. There is an erythematous border with the normal skin. Often, there is an associated hyperhidrosis.
A very rare form of tylosis, described by Howell-Evans, is associated with the almost certain development of esophageal carcinoma. This malignant related tylosis occurs at a later age, and is less uniform and less well sharply demarcated than the much more common non-cancer related tylosis.
Kindreds have been described in association with breast or ovarian carcinoma. A progressive form, mal de Maleda, has hyperkeratosis extending beyond the palms to the dorsum of the hands, forearms, and lower legs.
- Keratolytics such as 5-10% salicylic acid in an ointment base, or in 70% propylene glycol, with or without occlusion, can provide some symptomatic relief.
- Dermatophyte infections are common and should be treated.
- Etretinate and acitretin are effective, but as treatment must be continued lifelong, systemic retinoids should be used only in the most severe cases as side effects are problematic.