[Low-dose prophylactic oral isotretinoin treatment for 18 years in a patient with epidermodysplasia verruciformis and numerous squamous cell carcinomas].

Epidermodysplasia verruciformis (also known as Lewandowsky-Lutz dysplasia) is an extremely rare autosomal recessive genodermatosis, in which the skin is unusually sensitive to human papilloma viruses (HPV). It is associated with a high risk of developing non-melanocytic skin tumors. Treatment with keratolytic retinoids is currently considered to be the most effective therapy. Retinoids have a broad spectrum of activity and inhibit the growth of squamous cell carcinoma and other malignant tumors. We report the case of an 81-year-old woman who had been receiving prophylactic treatment with oral isotretinoin at a daily dose of 1.0-0.33 mg/kg bodyweight for about 18 years because of her epidermodysplasia verruciformis (HPV types 9 & 57 detected). We observed a reduction of the incidence of squamous cell carcinomas of the skin and presume a causal relationship between the treatment with this retinoid and the reduction of squamous cell carcinomas of the skin in this patient.