Pyrophosphate arthropathy as a late complication of juvenile chronic arthritis.

Pyrophosphate arthropathy is an age-related disease rarely seen in those under 45 years of age. We report 2 patients with early onset pyrophosphate arthropathy in joints previously affected by juvenile chronic arthritis. This previously undescribed association supports the hypothesis that joint damage may predispose to calcium pyrophosphate dihydrate crystal deposition and lead to secondary pyrophosphate arthropathy.