The contribution of direct immunofluorescence to the diagnosis of lupus erythematosus.

The contributions of direct immunofluorescence, light microscopy and serology to the investigation of 52 patients with possible lupus erythematosus were studied. Direct immunofluorescence was found to be most valuable in the investigation of possible systemic lupus erythematosus whilst only of supportive value in the investigation of possible chronic discoid lupus erythematosus. The importance of performing light microscopy before direct immunofluorescence in cases of possible chronic discoid lupus erythematosus is shown.