[A case of very late onset overlap syndrome of systemic sclerosis and systemic lupus erythematosus].
A 88-year-old woman was admitted with appetite loss and dehydration in April 1999. She first noticed finger swelling in May 1996 and systemic sclerosis (SSc) was diagnosed in February 1997 on the basis of a clinical picture of low-grade fever, diffuse skin thickening, Raynaud's phenomenon, and pulmonary fibrosis. Retrospectively pulmonary fibrosis could have been identified on chest X ray film in September 1995. Although her appetite loss and dehydration were improved by hydration, pleural effusion continued. After detailed examinations, anti-topoisomerase 1 (Scl-70) antibody, anti-Sm antibody, and an anti-double-stranded DNA antibody (dsDNA) were found in her serum. However, the other antibodies to anti-SS-A, SS-B, Jo-1, and RNP were not detected. These results suggest that this elderly case was a very late onset overlap syndrome of systemic lupus erythematosus (SLE) and SSc. Thus, the pleural effusion in this case may have been caused by SLE-associated pleuritis. Although the late onset elderly cases with overlap syndrome are very rare, SLE, SSc, and their combination can be found in aged patients over 80 years old. SLE and SSc should be carefully considered for the differential diagnosis of pleural effusion and skin thickening even in elderly patients.