The importance of direct immunofluorescence in the diagnosis of bullous skin lesions is illustrated by the following report of bullous systemic lupus erythematosus (SLE). Direct immunofluorescence of the bullous lesions of SLE demonstrated the lupus band six months before the lupus erythematosus cell phenomenon became positive. Direct immunofluorescent studies may provide an important tool for the early diagnosis of SLE particularly when other tests are not helpful.
Pedro SD, Dahl MV. Direct Immunofluorescence of Bullous Systemic Lupus Erythematosus. Arch Dermatol. 1973;107(1):118-120. doi:10.1001/archderm.1973.01620160086028