How do you make a diagnosis of SCLE?

SCLE is a clinical diagnosis based on the presence of a typical photodistributed eruption and a skin biopsy consistent with cutaneous LE. Direct immunofluorescence testing may also be helpful. In addition to granular deposition of immunoreactants at the dermal–epidermal junction, particulate deposition of IgG within the epidermis has been described in SCLE. Most patients with SCLE have circulating antibodies to Ro/SS-A (Sjögren’s syndrome A) and, less commonly, to La/SS-B (Sjögren’s syndrome B). These antibodies are not demonstrable in all patients with SCLE; thus, their absence does not exclude this diagnosis. Additionally, a negative ANA does not exclude the diagnosis of SCLE, and some patients may have positive titers to Ro/SS-A or La/SS-B but test negative for ANA.