Palmoplantar keratodermas are a heterogeneous group of inherited keratinization disorders of varying severity. Olmsted syndrome (OS) is one of the rarest diseases in this group, which is manifested by progressive mutilating keratoderma of the palms and soles, periorificial hyperkeratosis, and alopecia of varying severity. Most cases of OS arise as a result of pathogenic variants in the TRPV3 gene. In keratinocytes, TRPV3 forms a signaling complex with the epidermal growth factor receptor, which in turn leads to the activation of many downstream kinases, including serine-threonine kinase (mTOR), which is the main regulator of cell growth and proliferation. Enhanced activation of the mTOR pathway leads to various inflammatory, hyperproliferative and neoplastic diseases of the skin, including OS. There is currently no effective treatment for OS; topical, physiotherapeutic and medicinal agents do not have a significant clinical effect. The search for new pathogenetically substantiated treatment methods is an important task of modern dermatology. The article describes a clinical example of the first successful use of sirolimus in in a patient with OS in Russia.

Keywords: Olmsted syndrome, palmoplantar keratoderma, sirolimus