Devergie disease, or pityriasis rubra pilaris, is a poorly studied and rare disease, which prevalence is estimated at about 1 in 400 thousand. The article provides relevant data on the classification of Devergie disease, features of the course and clinical manifestations of each of the 6 types of the disease, as well as the ap-proximate occurrence of these types. Erythroderma can occur in Devergie disease, but data on the incidence of this manifestation vary significantly. The article presents a clinical case of type 1 Devergie disease. This case is of particular interest, since the disease began not according to the classical scheme, i.e., with appearance of an erythematous spot, but with extensive areas of erythroderma. This case is intended to draw attention to the fact that dermatological diseases do not always develop in a typical way, and the correct diagnosis often requires a histological examination. Key words: pityriasis rubra pilaris, Devergie disease, erythroderma, clinical case. For citation: Plieva K.T., Denisova E.V., Bobrov M.A. et al. Rare dermatological diseases: Devergie disease. Consilium Medicum. 2020; 22 (7): 54–56. DOI: 10.26442/20751753.2020.7.200187