PATTERN OF JOINT INVOLVEMENT IN CHILDREN WITH LYME ARTHRITIS

Following the clinical observation of a peculiar joint pattern in chil dren with Lyme arthritis, we classified the pattern of joint involveme nt in children with oligoarticular arthritis (2-4 joints) of different causes, including Lyme arthritis, juvenile chronic arthritis and juve nile spondyloarthropathy, as: (1) symmetrical: arthritis of the same j oints on both sides of the body; (2) unilateral: all involved joints o n the same side; (3) predominantly unilateral: joints involved on the contralatral side also showed ipsilateral involvement: (4) oblique: in volvement on the contralateral side of one or mote joints that did not show ipsilateral involvement. The oblique pattern was found in 13 of 42 children with early-onset pauciarticular juvenile chronic arthritis and in 17 of 32 patients with juvenile spondyloarthropathy. but not i n 32 of 32 children with Lyme arthritis. If confirmed, these results m ay have implications for the diagnosis and pathogenesis of Lyme arthri tis.