Pachydermodactyly is a rare benign form of digital fibromatosis with fusiform asymptomatic noninflammatory swelling of the proximal interphalangeal joints of the hand, most often involving digits II-IV and less often the thumb and fifth finger. It is usually bilateral and symmetric, but in rare cases, it can be unilateral. While the proximal interphalangeal (PIP) joints are most often affected, the distal interphalangeal (DIP) joints and the metacarpophalangeal (MCP) joints can be affected as well.

Pachydermodactyly most commonly begins during puberty, progresses, and then stabilizes in later adolescence, with males being affected 4 times more often than females.

The skin around the affected joints may appear hyperkeratotic, lichenified, and hyperpigmented. X-ray investigation will show periarticular soft tissue swelling without bony or articular changes.

Laboratory investigation for inflammatory arthropathies is usually negative. While the etiology is unknown, some investigators think it may result from repetitive mechanical stimulation / trauma and hormonal changes.