Sarcoidosis is a granulomatous disease affecting various organs and systems. In the last decade, there has been an increase in the incidence of sarcoidosis with an annual increase in the number of patients by about 2%. This can partly be explained by the improvement of his diagnosis. Sarcoidosis occurs at any age, but people between the ages of 30 and 40 are at risk, and children rarely get sick. At present, genetic aspects of sarcoidosis are widely discussed. In recent years, there has been a significant pathomorphosis of clinical manifestations of tuberculosis and other respiratory diseases, the emergence of various comorbid conditions has been described, which significantly complicates the diagnosis of sarcoidosis, and often difficulties arise in prescribing adequate therapy. Lefgren’s syndrome is an acute form of sarcoidosis that affects the lungs, joints and skin. Based on the example of a clinical case, modern approaches to the diagnosis and treatment of sarcoidosis with skin lesions are considered. One of the significant clinical symptoms of sarcoidosis in the patient was skin lesion in the form of erythema nodosum — red painful subcutaneous formations, which has similar symptoms with erysipelas, skin tuberculosis, dermatomycosis, panniculitis. The examination of the patient included laboratory diagnostics, computed tomography of the chest, and histological examination of the skin. The examination confirmed the diagnosis of sarcoidosis. Timely diagnosis made it possible to carry out effective treatment and achieve a significant regression of the symptoms of the disease.