RHEUMATOID ARTHRITIS

Introduction:  Rheumatoid arthritis (RA) is an inflammatory disorder of unknown origin that primarily involves the synovial membrane of the joints. Phagocytosis produces enzymes within the joint. The enzymes break down collagen, causing edema, proliferation of the synovial membrane, and ultimately pus formation. Pus destroys cartilage and erodes the bone. The consequence is loss of articular surfaces and joint motion.  Muscle fibers undergo degenerative changes. Tendon and ligament elasticity and contractile power are lost.

PREVALENCE:  RA affects 1% of the population worldwide, affecting women two to four times more often than men.

CLINICAL MANIFESTATIONS:  Clinical features are determined by the stage and severity of the disease.  Joint pain, swelling, warmth, erythema, and lack of function are classic symptoms.  Palpation of joints reveals spongy or boggy tissue. Fluid can usually be aspirated from the inflamed joint.

CHARACTERISTIC PATTERN OF JOINT INVOLVEMENT:  Begins with small joints in hands, wrists, and feet.  Progressively involves knees, shoulders, hips, elbows, ankles, cervical spine, and temporomandibular joints.  Symptoms are usually acute in onset, bilateral, and symmetric.  Joints may be hot, swollen, and painful; joint stiffness often occurs in the morning.  Deformities of the hands and feet can result from misalignment and immobilization.

EXTRAARTICULAR FEATURES:  Fever, weight loss, fatigue, anemia, sensory changes, and lymph node enlargement.  Raynaud’s phenomenon (cold- and stress-induced vasospasm).  Rheumatoid nodules, nontender and movable; found in subcutaneous tissue over bony prominences.  Arteritis, neuropathy, scleritis, pericarditis, splenomegaly, and Sjögren syndrome (dry eyes and mucous membranes)

ASSESSMENT AND DIAGNOSTIC METHODS: Several factors contribute to an RA diagnosis: rheumatoid nodules, joint inflammation detected on palpation, laboratory findings, extra-articular changes.  Rheumatoid factor is present in about three fourths of patients.  RBC count and C4 complement component are decreased; erythrocyte sedimentation rate is elevated.  C-reactive protein and antinuclear antibody test results may be positive.  Arthrocentesis and x-rays may be performed.

MEDICAL MANAGEMENT:  Treatment begins with education, a balance of rest and exercise, and referral to community agencies for support. Early RA: medication management involves therapeutic doses of salicylates or NSAIDs; includes new COX-2 enzyme blockers, antimalarials, gold, penicillamine, or sulfasalazine; methotrexate; biologic response modififiers and tumor necrosis factor-alpha (TNF) inhibitors are helpful; analgesic agents for periods of extreme pain. Moderate, erosive RA: formal program of occupational and physical therapy; an immunosuppressant such as cyclosporine may be added.  Persistent, erosive RA: reconstructive surgery and corticosteroids. Advanced unremitting RA: immunosuppressive agents such as methotrexate, cyclophosphamide, azathioprine, and leflunomide (highly toxic, can cause bone marrow suppression, anemia, GI tract disturbances, and rashes).  RA patients frequently experience anorexia, weight loss, and anemia, requiring careful dietary history to identify usual eating habits and food preferences. Corticosteroids may stimulate appetite and cause weight gain. Low-dose antidepressant medications (amitriptyline) are used to reestablish adequate sleep pattern and manage pain.

RELATED; 

1.  MEDICINE AND SURGERY

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