A 36-year-old woman had an 8-year history of systemic lupus erythematosus (SLE) and was being treated with 10 mg/d of prednisone. She presented with a 6-month history of intermittent fever and multiple painful multi skin erythematous macules in her button, hips and extremities that had slowly enlarged to 8 cm×4 cm in diameter. The lesions started as painful erythematous macules, which eventually ulcerated and scared. Laboratory tests showed leukopenia, protenuria, positive anti-double strand DNA and hypocomplementemia. Cultures of the bottom ulcer were E. Coli, fugus and Tuberculous mycobacteria were both negative. Biopsy was performed and revealed necrosis of epidermis, thrombus and cellulose degeneration in epidermis with neutrophils karyorrhexis and vasculitis. Her SLE was active, so she was prescribed antibiotics for 2 weeks and prednisone was added to 60 mg/d for a month. However her skin ulcers did not relieve. When prednisone was added to 120 mg/d with combination therapy of cyclophosphamide and hydroxychloroquine, her skin ulcer cicatrized gradually.