Hereditary palmoplantar keratoderma in the northernmost county of Sweden

A papular and a diffuse variety of hereditary palmoplantar keratoderma (Unna Thost) are described. It was not possible to demonstrate any histopathological differences between the two varieties. Of the patients examined 36.2% were found to have dermatophytosis in addition to hereditary palmoplantar keratoderma. The hyperkeratosis was smooth and uniform in both varieties. When scaling and fissuring did occur they were signs of dermatophytosis and not part of the clinical picture. The examination of biopsies stained with H&E and PAS showed that dermatophytosis in patients with hereditary palmoplantar keratoderma, especially those with recurrent vesicular eruptions, gave rise to a histopathological picture which was, in some respects, similar to that of acute vesicular eczema.