Contributor: Gordon K. Klintworth
Juvenile chronic arthritis (juvenile rheumatoid arthritis, Still disease) is three distinct disorders with different initial presentations. One type has >5 affected joints (polyarticular variant), a second type has < 4 involved joints (pauciarticular variant), and the third type presents with fever, a maculopapular rash lymphadenopathy and splenomegaly. An American classification of arthritis excludes juvenile ankylosing spondylitis [ankylosing spondylitis - juvenile] from the pauciarticular variant; an European classification includes juvenile ankylosing spondylitis in the pauciarticular variant.
A minority of persons with the polyarticular variant are rheumatoid factor positive and the likelihood of developing rheumatoid nodules and severe joint erosions is increased in patients who are rheumatoid factor positive.
In the pauciarticular variant the affected joints are ordinarily weight-bearing joints of the lower extremities and the arthritis frequently resolves completely. Some individuals in this group, mainly females, are HLA-B27 positive and at risk for a bilateral chronic iridocyclitis [iridocyclitis - chronic]. The iridocyclitis has an insidious onset with minimal ocular pain and redness. Common late sequelae are calcific band keratopathy  [keratopathy - calcific band], cataract, posterior synechiae, glaucoma and cystoid macular edema [edema - cystoid macular]. Most of these patients with chronic anterior uveitis [uveitis - chronic anterior] have antinuclear antibodies, but are negative for rheumatoid factor. Later in life some patients with the pauciarticular variant acquire rheumatoid factor and a severe erosive polyarthritis. Some patients with pauciatricular juvenile chronic arthritis develop ankylosing spondylosis later in life. As in adult rheumatoid arthritis [rheumatoid arthritis - adult] persons with polyarticular juvenile chronic arthritis who are rheumatoid factor positive are often HLA-DR4 positive. Iritis sometimes occurs in the variant of  juvenile chronic arthritis that has systemic manifestations, but rarely.