Subacute cutaneous lupus erythematosus: a decade's perspective.

Based upon the rather large worldwide experience that has been published recently, it would appear that the concept of subacute cutaneous LE as presented in our original reports starting 10 years ago is still a viable one. However, we must now also consider the possibility that these patients will occasionally develop other types of autoimmune disorders such as rheumatoid arthritis and Sjögren's syndrome and, on occasion, have their skin disease triggered by drugs such as hydrochlorothiazide. However, the majority of these patients will have recurrent skin disease activity and musculoskeletal symptoms as the major manifestations of their illness. Although most of these patients do have a relatively mild disease course, a small percentage seem to be at risk for developing potentially life-threatening complications of systemic LE. The future challenge in this area lies in identifying prognostic features that may correlate with this more aggressive disease course so that this subgroup of patients can be more efficiently managed. Our preliminary studies have suggested several candidates for further study: the papulosquamous/psoriasiform subacute cutaneous LE lesional subtype; development of acute cutaneous LE; resistance to antimalarials alone; leukopenia; high titer ANA; and the presence of circulating double-stranded DNA antibodies. Another possibility may include the rate of systemic disease onset. Discoid LE patients who have not developed clinically significant SLE manifestations within the first 2 years of the appearance of their skin lesions have a very low risk for suffering from severe SLE complications later in their disease course. The same question might be asked of subacute cutaneous LE. In addition, some subacute cutaneous LE patients have a single episode of disease activity followed by long-term, if not permanent, remission. More needs to be learned about this more benign pattern of illness in the hope of identifying favorable prognostic signs. Our impressions regarding subacute cutaneous LE disease outcome have mostly come from retrospective or point-prevalence types of clinical analyses; more prospective examinations of large groups of patients will be required to better address the issue of prognosis in subacute cutaneous LE. The data published to date suggest that this is a relatively homogeneous group of patients immunogenetically: they frequently have circulating anti-Ro auto-antibodies and often possess the HLA-DR3 phenotype. Much circumstantial evidence indicates that this particular genetically determined autoimmune response might be directly participating in pathogenesis of this form of LE-specific skin injury.(ABSTRACT TRUNCATED AT 400 WORDS)