RHEUMATOID ARTHRITIS

Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that our immune system attacks healthy cells in our body by mistake, causing inflammation (painful swelling) in the affected parts of the body.

By definition, RA is a chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, and by atrophy and rarefaction of bony structures.

If simplified ,Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, stiffness and loss of function in joints. It can affect any joint but is common in the wrist and fingers. More women than men get rheumatoid arthritis. It often starts between ages 25 and 55Although considered a "joint disease" rheumatoid arthritis is associated with involvement of extra-articular manifestations.

ETIOLOGY AND PATHOPHYSIOLOGY

Like many autoimmune diseases, the etiology of RA is multifactorial. Genetic susceptibility is evident.Smoking is the major environmental trigger for RA, especially in those with a genetic predisposition.Older age, a family history of the disease, and female sex are associated with increased risk of RA, although the sex differential is less prominent in older patients.

CLINICAL MANIFESTATIONS

Articular Manifestations

RA is characteristically a symmetric erosive disease. Although any joint, including the cricoarytenoid joint, can be affected, the distal interphalangeal, the sacroiliac, and the lumbar spine joints are rarely involved. The clinical features of synovitis are particularly apparent in the morning. Morning stiffness in and around the joints, lasting at least 1 h before maximal improvement is a typical sign of RA.

Hand involvement is the typical early manifestation of rheumatoid arthritis. Synovitis involving the metacarpophalangeal, proximal interphalangeal and wrist joints causes a characteristic tender swelling on palpation with early severe motion impairment and no radiologic evidence of bone damage.

Extra articular Manifestation

Fatigue, fever, weight loss, and malaise are frequent clinical signs which can be associated with variable manifestations of extra-articular involvement such as rheumatoid nodules, vasculitis, hematologic abnormalities, Felty's syndrome, and visceral involvement.

INVESTIGATIONS AND DIAGNOSIS

RA typically present with pain and stiffness in multiple joints. The wrists, proximal interphalangeal joints, and metacarpophalangeal joints are most commonly involved. Morning stiffness lasting more than one hour suggests an inflammatory etiology. Boggy swelling due to synovitis may be visible Patients may also present with more indolent arthralgias before the onset of clinically apparent joint swelling. Systemic symptoms of fatigue, weight loss, and low-grade fever may occur with active disease.

Laboratory tests:

• Erythrocyte sedimentation rate (ESR) and C-Reactive Protein (CRP): These are acute phase reactants which rises in inflammatory conditions but not diagnostic.

• Rheumatoid factor: Is an auto antibody which is rised in blood suggestive of RA.

• Anti-citrullinated protein antibody: More specific auto antibody to RA.

CONCLUSION

Rheumatoid arthritis is the most commonly diagnosed systemic inflammatory arthritis. Women, smokers, and those with a family history of the disease are most often affected. Criteria for diagnosis include having at least one joint with definite swelling that is not explained by another disease. The likelihood of a rheumatoid arthritis diagnosis increases with the number of small joints involved.