Erythrodermic mycosis fungoides (eMF) is an atypical severe form of mycosis fungoides resulting from persistent and treatment-resistant disease. eMF manifests as generalized skin bluish lesions, intense itching, secondary lymph-adenopathy, and significant deterioration of quality of life. A differential diagnostic algorithm for various forms of eryth-rodermia is suggested. The paper presents a clinical case of eMF with spots and plaques that skipped the tumor stage. Experience of eMF treatment using vorinostat, gemcitabine, doxorubicin, and alemtuzumab is described.