Enthesitis-related arthritis.

Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis of childhood. Currently, it is characterized by seven categories. The enthesitis-related arthritis (ERA) category usually affects boys older than 6 years and presents with lower limb asymmetrical arthritis associated with enthesitis. Later, these children can develop inflammatory lumbosacral pain (IBP). These children are at risk of developing acute anterior uveitis. A recently devised disease activity index, Juvenile Spondyloarthropathy Disease Activity Index (JSpADA), has been validated in retrospective cohorts. The corner stone of treatment is NSAIDs, local corticosteroid injections, and exercise. Methotrexate and sulfasalazine can be used for peripheral arthritis while anti-tumor necrosis factor (TNF) agents are sometimes used to treat refractory enthesitis and sacroiliitis. Almost two third of patients with ERA have persistent disease and often have impairments in their quality of life. The presence of hip or ankle arthritis and a family history of spondyloarthropathy or polyarticular joint involvement at onset are associated with poorer prognosis.