Pachydermodactyly: a review.

Synovitis is the characteristic feature of inflammatory joint disease. If synovitis is localized to interphalangeal joints, rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis are among the most common differential diagnoses. The absence of pain, tenderness, and limitation of function despite progressive swelling of proximal interphalangeal joints suggests an alternative diagnosis, for example pachydermodactyly (PDD). This is a benign disease, associated with asymptomatic, progressive swelling of periarticular soft tissue, which usually occurs in young males. PDD is probably the result of repetitive mechanical stimulation. One hundred and twenty-one cases have been reported in the literature. Some of these were initially misdiagnosed and treated for inflammatory arthritis. We provide a comprehensive review of the literature on pachydermodactyly to promote awareness of this rare but important differential diagnosis of arthritis.