FIELD : medicine.SUBSTANCE : invention relates to the field of medicine and represents a method for differential diagnosis of fungous mycosis from chronic dermatoses, involving confocal laser scanning microscopy of the most infiltrated skin area, detection of pathomorphological signs and a score of their degree of severity, characterized by the fact that F is determined - a total diagnostic indicator of the above pathomorphological features by formula F = 1.76p1 + 0.4p2 + 1.738p3 + 1.498p4 + 1.56p5 + 1.44p6, where p1 is epidermal destruction (0 to 3 points); p2 - microabstracts Sodium (0 to 1 point); p3 - presence of atypical lymphocytes in epidermis (from 0 to 3 points); p4 - presence of atypical lymphocytes in dermo-epidermal junction (0 to 3 points); p5 - loss of papillary outline (from 0 to 3 points); p6 - presence of atypical lymphocytes in derma (from 0 to 3 points); and if F <5.8, chronic dermatosis is diagnosed, with value of 5.9?≤?F?≤?6.8 - diagnosis is not specified, and if F?≥?6.9 - fungoid mycosis.EFFECT : invention provides higher objectivity and accuracy of diagnosing mushroom mycosis in the patient.1 cl, 18 dwg, 4 tbl, 4 ex