Lupus erythematosus panniculitis: a clinicopathologic study

Lupus erythematosus panniculitis is a clinical variant of lupus erythematosus which involves the deep dermis and the subcutaneous fat. The purpose of this study was to ascertain the clinical profile of Asian patients with this condition.

This was a retrospective study of all histologically confirmed lupus panniculitis seen at our center between 1992 and 1997. The age, sex, past history/subsequent diagnosis of systemic lupus erythematosus (SLE), presence of clinical discoid lupus erythematosus (DLE) changes on overlying skin, direct immunofluorescence, serologic, and histologic findings were analyzed.

There were 12 cases of lupus panniculitis, two of which were in patients already diagnosed with SLE and one in which the patient subsequently evolved into SLE. The mean age at diagnosis was 31.3 years. The face (50%), upper limbs (33%), and scalp (25%) were the most common sites of involvement. Thirty-three per cent had clinical evidence of DLE on the overlying skin, whilst 67% had histologic features of DLE on the overlying skin. A lupus band was present in 36%. Antinuclear antibody (ANA) was positive in three of 11 cases; these were in the two patients who already had SLE and in the only patient who progressed to SLE. All of the cases showed fat necrosis and, in the majority of cases, there was associated lobular and paraseptal inflammation. Thirty-three per cent showed lymphocytic vasculitis and 75% had mucin deposition. None had lymphoid nodules, subepidermal hyalinization, or calcification.

Lupus panniculitis affects a younger age group in Asians as compared with the Western population. Although about one-third of patients show clinical evidence of overlying DLE, two-thirds of patients show histologic evidence of DLE. It tends to have a mild disease course in the majority of cases.