The American College of Rheumatology (1988 revised) developed
the following criteria for the classification of rheumatoid arthritis.
1. Morning Stiffness: This occurs in and around the joints and
lasts at least 1 hour before maximal improvement.
2. Arthritis of 3 or more joint areas: At least 3 joint areas
simultaneously have soft tissue swelling or fluid (not bony
overgrowth) observed by a physician. The 14 possible areas are
right or left proximal interphalangeal (PIP),
metatarsophalangeal (MTP) joints.
3. Arthritis of hand joints of at least one area swollen in a wrist,
MCP, or PIP joint.
4. Symmetric arthritis with simultaneous involvement of the same
joint areas on both sides of the body. Bilateral involvement of
PIPs, MCPs, and MTPs is acceptable without absolute
5. Rheumatoid nodules: Subcutaneous nodules are present over
bony prominences or extensor surfaces or in juxta-articular
6. Serum Rheumatoid Factor: Abnormal amounts of serum RF
are demonstrated by any method for which the result has been
positive in fewer than 5% of healthy control subjects.
7. Radiographic changes typical of RA on posteroanterior hand
and wrist radiographs, which must include erosions or
unequivocal bony decalcification localized in or most marked
adjacent to the involved joints. Osteoarthritic changes alone do
A patient can be classified as having RA if 4 of 7 criteria are
present. Criteria 1- 4 must be present for at least 6 weeks, and a physician
must observe criteria 2 – 5. These criteria are intended as a guideline for
classification of patients, often for research purposes. They do not
absolutely confirm or exclude a diagnosis of RA in a particular patient,
especially in those with early arthritis.
No pathognomonic test is available to confirm the diagnosis of RA;
instead, the diagnosis is made using clinical, laboratory, and imaging