Clinicopathological significance of cutaneous epidermal nuclear staining by direct immunofluorescence.

Epidermal antinuclear antibody (ANA) staining was noted during routine direct immunofluorescence (DIF) of skin biopsies from 22 cases at St John's Dermatology Centre over a 2-year period. We have reviewed the clinical, serological and immunopathological features of these patients. They comprised 13 cases of lupus erythematosus (LE), 3 dermatomyositis, 1 morphoea, 1 systemic sclerosis, 1 CREST syndrome, 1 mixed connective tissue disorder and 1 probable cutaneous sarcoidosis. Five (38.4%) patients with LE had moderate to severe oral mucosal involvement. Epidermal nuclear staining (ENS) was seen following IgG deposition in 21 cases and IgA in only 1 case. Complement C3 staining was an additional feature in 1 patient. Circulating ANA was absent in 7 cases at the time of biopsy, confirming that this pattern of staining does not occur as a result of tissue contamination during processing. The presence of ENS by DIF corroborates a diagnosis of a connective tissue disorder, and our results suggest that it may also be associated with oral involvement in L.E.