[Subacute cutaneous lupus: critical study].

Subacute cutaneous lupus erythematosus has been identified as a bioclinical entity associating particular clinical signs (diffuse superficial cutaneous lesions evolving without atrophy or scarring), biological markers (anti-Ro/SSA, HLA A1 B8 DR3) and a good prognosis. We assessed the reality of this entity: 1) all the anti-Ro/SSA sera at H.-Mondor Hospital was examined over a 2 year period; 58 of the 963 sera tested were positive. Thirty one of the 58 positive patients had lupus (53 p. 100), but only 12 (21 p. 100) had subacute cutaneous lupus; 2) a photographic dossier was examined by three dermatologists who classified the photos of 74 patients independently. All three observers agreed on the diagnosis of subacute cutaneous lupus erythematosus in only 32 p. 100 of cases. The 17 patients in whom the diagnosis was retained did not differ clinically from the 23 cases of systemic lupus. Anti-Ro/SSA antibodies were found in 42 p. 100 of cases of subacute cutaneous lupus and in 23 p. 100 of cases of systemic lupus erythematosus (not significant). The results of this double blind study indicate that the reality of subacute cutaneous lupus erythematosus as a separate entity is debatable.