TIS                         
Chapter 6
Arthritis


OVERVIEW
CriterionDefinition


1. Morning
Morning stiffness in and around the joints,
stiffness lasting at least 1 hour before maximal
improvement
2. Arthritis of 3
or more joint areas
At least 3 joint areas simultaneously have had
soft tissue swelling or fluid (not bony
overgrowth alone) observed by a physician. The
14 possible areas are right or left PIP, MCP,
wrist, elbow, knee, ankle, and MTP joints
3. Arthritis of
hand joints
At least 1 area swollen (as defined above) in a
wrist, MCP, or PIP joint
4. Symmetric
arthritis
Simultaneous involvement of the same joint areas
(as defined in 2) on both sides of the body
(bilateral involvement of PIPs, MCPs, or MTPs is
acceptable without absolute symmetry)
5. Rheumatoid
nodules
Subcutaneous nodules, over bony prominences, or
extensor surfaces, or in juxtaarticular regions,
observed by a physician
6. Serum
rheumatoid factor
Demonstration of abnormal amounts of serum
rheumatoid factor by any method for which the
result has been positive in 5% of normal
control subjects
7. Radiographic
changes
Radiographic changes typical of rheumatoid
arthritis on posteroanterior hand and wrist
radiographs, which must include erosions or
unequivocal bony decalcification localized in or
most marked adjacent to the involved joints
(osteoarthritis changes alone do not quality)

* For classification purposes, a patient shall be said to have rheumatoid arthritis if he/she has satisfied at least 4 of these 7 criteria. Criteria 1 through 4 must have been present for at least 6 weeks. Patients with 2 clinical diagnoses are not excluded. Designation as classic, definite, or probable rheumatoid arthritis is not to be made. Juvenile rheumatoid arthritis is characterized by chronic synovial inflammation of unknown cause. It affects an estimated 65,000 to 70,000 children in the United States. The disease may develop at any age during childhood, and girls are more often affected than boys; however, sex and age ratios differ in the various subgroups of JRA. Diagnosis of definite JRA requires at least six consecutive weeks of objective synovitis. The type of arthritis is determined according to the symptoms experienced during the first six months of the disease. Adherence to these important criteria, along with a careful history and physical evaluation, will generally lead to a correct diagnosis. Signs and symptoms of JRA vary from child to child. There is no single test that makes a diagnosis of JRA. The most common features of JRA are: Alternative nomenclature to JRA remains controversial, with juvenile chronic arthritis used by some European investigators, while other American researchers prefer juvenile arthritis. The current American College of Rheumatology (ACR) classification of syndromes considered to be juvenile rheumatoid arthritis, as outlined in includes three onset subtypes: pauciarticular, polyarticular, and systemic. Whether these subtypes are distinctive diseases resulting from different causes or varying responses to common factors is unknown. No laboratory test is diagnostic for JRA, although the presence of rheumatoid factors (RF), antinuclear antibodies (ANA), and certain HLA antigens may assist in classifying patients . Baseline joint roentgenograms are important to allow assessment of later bone growth or damage, but they are not diagnostic except when revealing late, characteristic articular damage. No clear evidence of a genetic predisposition for juvenile forms of arthritis exists, except in the case of pauciarticular disease in older children and familial spondylarthropathies, which may be associated with HLA-B27

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