Hereditary keratoderma of Unna-Tost in a patient with atopic dermatitis

Abstract

Unna-Toast's keratoderma is a disease belonging to the group of genodermatoses with an autosomal dominant type of inheritance and characterized by hyperkeratosis on the palms and soles. This nosology can manifest itself at any age as an independent process, but more often it debuts at 12 years of age, in some cases combined with various congenital malformations of ectodermal origin. The prevalence of this disease ranks second among hereditary dyskeratoses, however, it is rare in the practice of a dermatologist and there are no static data on the disease. The article presents a clinical observation of Unna-Toast's keratoderma that first appeared against the background of atopic dermatitis. The clinical picture is represented by smooth yellow horny layers located on the palms and soles, with a sharply defined border and an erythematous corolla along the periphery. Other areas of the skin are represented by lichenification foci with small-lamellar peeling, excoriations and serous-hemorrhagic crusts on the surface. This clinical case confirms the possibility of manifestation of hereditary hyperkeratosis against the background of aggressive atopic dermatitis. Unna-Tost's keratoderma is of high interest in the practice of a dermatologist and requires a detailed description of the available clinical cases, due to the rare occurrence of this nosology in the population.