A Rare Case of Overlap Syndrome with Diffuse Systemic Sclerosis, Rheumatoid Arthritis, and Cutaneous Sarcoidosis

Overlap syndrome is defined as a disease entity that satisfies the classification criteria of at least two connective tissue diseases occurring concurrently or separately in a single patient. Here, we report a rare case of a 59-year-old woman with diffuse systemic sclerosis with lung involvement-rheumatoid arthritis overlap syndrome accompanied by cutaneous sarcoidosis. Although there is no consensus for the optimal treatment of overlap syndrome to date, this case of co-existing rheumatoid arthritis and systemic sclerosis with interstitial lung disease successfully responded to abatacept.