Unna-Thost Palmoplantar Keratoderma

Unna-Thost palmoplantar keratoderma is a type of diffuse palmoplantar keratoderma that mostly affects the palms of the hands and soles of the feet. It usually begins in early childhood with redness of the palms and soles. The palms and soles gradually become thicker and develop a yellowish, waxy appearance. Increased sweating (hyperhidrosis) is quite common and there is a tendency to get fungal and bacterial infections of the feet. This condition usually does not extend beyond the hands and feet. It may affect the knuckle pads and nails, but usually does not involve the thin skin on the top of the feet or hands. Unna-Thost palmoplantar keratoderma is inherited in an autosomal dominant pattern and caused by genetic changes in the KRT1 gene. Diagnosis is based on a clinical exam and the symptoms. The results of genetic testing may be helpful for confirming the diagnosis. Treatment is focused on managing the symptoms and includes mechanical debridement, special lotions for the skin, and medication.