Rheumatoid Arthritis
Pathophysiology/Etiology
- Systemic autoimmune disorder; chronic inflammatory disease
- Etiology is unknown; due to both genetic and environmental factors, as well as endocrinologic and autoimmune factors
- Synovial tissues are primary target → once RA is initiated, synovial tissues because the site of a complex interaction of T cells, B cells, macrophages, and synovial cells → resultant proliferation of synovial tissues causes production of excessive amounts of synovial fluid → synovitis causes destruction of cartilage and marginal bone, and stretching or rupture of joint capsule as well as tendons and ligaments
- More common in women and older people
- Age: 40-75 years old
- Risk factors: family history, lower socioeconomic status, smoking
Signs/Symptoms
- Classic presentation: symmetric polyarthritis affecting the small joints of the feet and hands, and sometimes larger joints such as the wrists, ankles, shoulders, and knees
- Cardinal features: joint swelling, joint tenderness, dec ROM, morning stiffness
- Other symptoms: morning stiffness, fatigue, weakness, weight loss, low-grade fevers
- Differential diagnosis: Many diseases can mimic RA – hepatitis B/C, parovirus, rubella, Epstein-Barr virus, systemic lupus, psoriatic arthritis, reactive arthritis
Diagnostic Tools
- Most important positive findings: joint swelling (rather than joint pain alone), elevated inflammatory markers, positive antibodies (rheumatoid factor and cyclic citrullinated peptide) and erosive changes seen on radiographs
- Erythrocyte sedimentation rate (ESR) or C-reactive protein, serum rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibodies, complete blood count (CBC), synovial fluid analysis, radiography of involved joints, musculoskeletal ultrasonography, magnetic resonance imaging (MRI)
- Assessment of disease activity and treatment response based on: Disease Activity Score (DAS-28), Health Assessment Questionnaire (HAQ), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), Routine Assessment of Patient Index Data (RAPID), or American College of Rheumatology (ACR) response criteria
Prognosis
- Shortens survival, significantly affects quality of life in most patients
- Lifelong, progressive disease that produces significant morbidity and premature mortality
- Observational studies portray treated rheumatoid arthritis as a serious long-term disease with dominant extra-articular features, limited treatment options, and poor outcomes
Treatment
- Starts with a single nonbiologic disease-modifying antirheumatic drug (DMARD), in addition to analgesic meds, and sometimes also corticosteroids
- DMARDs reduce synovitis and systemic inflammation and improve function
- Goals: control disease activity, slow rate of joint damage, minimize pain, stiffness, inflammation, and complications, improve functional status and quality of life
- Physical Therapy Implications: aerobic and strength exercises, patient education, enhancement of self-management
- Because RA is an independent risk factor for osteoporosis, fracture, and cardiovascular morbidity and mortality, all patients with RA must be evaluated and treated
Prevention
- Decrease the number of people who smoke
Differential Diagnosis
- Referral to a rheumatologist is strongly recommended if there is uncertainty over diagnosis