Round fingerpad sign: an early sign of scleroderma. We describe a clinical skin sign in scleroderma termed round fingerpad sign. This term refers to disappearance of the peaked contour on fingerpads and replacement with a hemisphere-like fingertip contour; this change is especially apparent on the ring fingers. A positive round fingerpad sign was found in 72 of 72 ring fingers in 36 patients with progressive systemic sclerosis in 69 of 72 ring fingers in patients with mixed connective tissue disease, and in 24 of 24 ring fingers of patients with Raynaud's phenomenon and sclerodactyly. In contrast, a negative round fingerpad sign was seen in 240 of 240 fingers in normal women (controls). The high sensitivity of this sign is noteworthy. A positive round fingerpad was seen in sign not only typical scleroderma patients but also in groups with less severe skin sclerosis (i.e., in those patients with mixed connective tissue disease or those with Raynaud's phenomenon and sclerodactyly). The sign is a new and useful clinical marker for the early diagnosis of scleroderma. 