Abstract： A case of lepromatous leprosy is reported.A 39 -year- old female presented with symmetric polyarthritis and jelly-colored papules on the upper limbs and face accompanied by photosensitivity,fever and fatigue for half a year.The lesions were itchy and worsened after sun exposure.Laboratory examination revealed that the urinary protein was strongly positive,hemoglobin level 97 g/L,platelet count 51 x 109/L,serum complement 3 (C3) level 560 mg/L (reference value: 850-1930 mg/L),C4 level 103 mg/L (reference value: 120-360 mg/L),antinuclear antibody titer 1: 160.Based on these findings,she was diagnosed with systemic lupus erylhematosus,and trealed with oral prednisone 50 mg,thalidomide 100 mg,and hydroxychloroquine 200 mg per day.Subscquently,systemic symptom improved,whereas the skin lesions were progressively exacerbated with the development of nasal septum and palate perforation 2 years: after the treatment.Finally,histopathological examination and acid fast stain confirmed a diagnosis of lepromatous leprosy.This case implies that lepromatous leprosy may manifest as multisystemic damage with the presence of autoantibodies,and dermatologists should be on guard against the misdiagnosis of lepromatous leprosy as rheumatic disease.