A chronic inflammatory disease of variable severity
that affects the joints and may involve the connective tissues and viscera.
Juvenile Rheumatoid Arthritis (JRA); Still Disease; Still
Chauffard Disease. The International League of Associations of Rheumatologists Task Force on
the Classification of Childhood Arthritis has proposed that the previously
used terminology of juvenile rheumatoid arthritis be discarded and superseded by the umbrella term
juvenile idiopathic arthritis (JIA).
Approximately 10-20:100,000 children. A particularly
high incidence has been described in Native Americans and in parts of
Scandinavia. No sexual predilection exists, however, the oligoarticular and
polyarticular forms tend to be more common in girls, whereas the
systemic-onset form of the disease affects both genders equally.
A complex genetic inheritance pattern is
likely but is yet undefined.
The disease is caused by chronic synovial
inflammation of unknown origin characterized by B-lymphocyte infiltration.
Synovial proliferation seems to be the result of cytokines released by
invading macrophages and T cells. Lymphocytic infiltration has been
suggested to induce angiogenesis, thereby maintaining the disease process.
Destruction of the joint cartilage and, later, of the bone is caused by the
pannus. The etiology of the condition is unclear, but associations with
particular HLA haplotypes (e.g., HLA-B27) have been observed.
The previous American College of Rheumatology
classification of JRA referred to oligoarticular arthritis, polyarticular
arthritis, or systemic illness of at least 6 weeks' duration. In the current
classification, JIA is defined as an arthritis occurring before 16
years of age, lasting for at least 6 weeks without an established cause and excludes
psoriatic arthropathy and juvenile spondyloarthropathy. The diagnosis is
made by exclusion of alternative conditions (e.g., malignancy or
infection). The clinical course is variable and may resolve after a single
episode, whereas systemic and articular flare-ups occur frequently in
The polyarticular form of Chauffard syndrome may
occur in children at any age. The oligoarticular and the systemic-onset
forms usually occur in early childhood, although later onset (including
adolescence) has been described. Skeletal features include generalized
osteopenia, joint involvement, either oligoarticular (1-4 joints, also
called pauciarticular) or polyarticular (≥5 joints), with cartilage destruction
preceding the bony involvement. Effusions in affected joints and radial
deviation of the wrist may occur. Joint inflammation may be associated with
muscle atrophy. Bony fusion of the cervical spine is common and most
frequently occurs at the C2-C3 level secondary to apophyseal ankylosis.
Atlantoodontoid instability may occur secondary to pannus formation in the
joint, odontoid erosions, and ligamentous laxity. Dental malocclusion and
mandibular hypoplasia associated with mandibular retrognathia are common and
present in about one fourth of affected children. Limited mouth opening may
occur in the absence of symptoms such as temporomandibular joint pain at
rest or during function. Stridor may occur secondary to cricoarytenoiditis.
Other findings may include uveitis, pericarditis, hepatosplenomegaly,
lymphadenopathy, a pink, linear macular rash on trunk and extremities,
anemia, and pulmonary interstitial fibrosis. Systemic features such as fever ...