Successful conservative therapy of pincer nail syndrome

3 cases of seronegative synovitis syndrome were reported. Two elderly women and one man presented with symmetrical polysynovitis of acute onset involving most of their appendicular joints and flexor digitorum tendons associated with pitting edema of the dorsum of both hands and both feet. Rheumatoid factor was absent from serum samples in all and no radiologically evident erosions developed. All the three patients had a benign course and the disease resolved completely within 2-18 months after the onset. None had deformities, erosions and/or relapse after being followed for 22-34 months. Literatures on this syndrome were reviewed.