Rheumatoid Arthritis
A chronic autoimmune disease causing symmetric joint pain, swelling, and stiffness, which can lead to permanent joint damage if untreated.
Emergency Management: Septic arthritis in a previously damaged rheumatoid joint. Requires emergent joint aspiration for synovial fluid culture, IV antibiotics (Vancomycin and Ceftriaxone), and orthopedic washout.
Rheumatoid Arthritis is a chronic, systemic, autoimmune inflammatory disorder that primarily targets the synovial lining of joints. It causes a symmetric, erosive polyarthritis that eventually leads to cartilage destruction, bone erosions, and joint deformity. It can also involve extra-articular organs including the lungs, heart, and eyes.
Detailed Overview
RA affects small joints of the hands and feet first, producing significant pain, swelling, and prolonged morning stiffness. The hallmark is the formation of a 'pannus'—hypertrophied, inflamed synovial tissue that invades and destroys adjacent cartilage and bone. Beyond the joints, systemic inflammation accelerates atherosclerosis, drastically increasing cardiovascular mortality. Early, aggressive use of Disease-Modifying Antirheumatic Drugs (DMARDs) within the 'window of opportunity' is critical to halt joint destruction.
Epidemiology & Demographics
Prevalence is approximately 0.5-1% of the adult population globally. It is 2-3 times more common in women than in men. Peak onset is between ages 30 and 50 in women, and slightly later in men.
Etiological Mechanism
Arises from a loss of immunologic tolerance to self-antigens. It requires a genetic predisposition (HLA-DRB1 alleles containing the 'Shared Epitope') combined with environmental triggers, most notably cigarette smoking, which induces citrullination of proteins in the lungs.
Primary Causes
Primary cause is autoimmune CD4+ T-cell and B-cell activation against citrullinated proteins (anti-CCP). Environmental triggers (smoking, periodontitis via Porphyromonas gingivalis, viral infections like EBV) trigger mucosal inflammation that breaks immune tolerance in genetically susceptible hosts.
Environmental insults cause citrullination of proteins (e.g., vimentin, type II collagen). Antigen-presenting cells display these to CD4+ T cells. T cells activate B cells to produce autoantibodies (Rheumatoid Factor and Anti-Cyclic Citrullinated Peptide). Immune complexes deposit in the synovium, activating complement. Macrophages and T cells in the synovium secrete abundant pro-inflammatory cytokines (TNF-alpha, IL-1, IL-6). This drives synovial fibroblasts and macrophages to proliferate, forming a thickened, hyperplastic pannus. The pannus secretes matrix metalloproteinases (MMPs) that degrade cartilage, and RANK-ligand, which hyperactivates osteoclasts to cause periarticular bone erosions.
Diagnostic Criteria & Guidelines
Diagnosed using the 2010 ACR/EULAR classification criteria. Requires a score >= 6/10 based on: number of small joints involved, positive serology (RF and anti-CCP), elevated acute phase reactants (CRP, ESR), and symptom duration >= 6 weeks.
Initiate Conventional Synthetic DMARD (csDMARD) immediately upon diagnosis. Methotrexate 15-25 mg PO or SC once weekly, co-administered with Folic acid 1-5 mg daily. Bridging therapy with short-term systemic glucocorticoids (Prednisone 5-10 mg daily for 2-4 weeks) is used to control symptoms while MTX takes 6-12 weeks to act.
Second-Line & Adjunctive Therapy
If target (remission or low disease activity) is not reached with MTX, add a Biologic DMARD (bDMARD). Options include TNF-alpha inhibitors (Adalimumab 40 mg SC every 2 weeks, Etanercept 50 mg SC weekly) or IL-6 inhibitors (Tocilizumab). Alternatively, Targeted Synthetic DMARDs (tsDMARD) like JAK inhibitors (Upadacitinib 15 mg PO daily).
Surgical & Procedural Management
Synovectomy for isolated resistant joints. Tendon transfer or repair for ruptured tendons. Total joint arthroplasty (knee/hip replacement) for end-stage destroyed joints to restore mobility and relieve pain.
Patient Counseling & Advice
Stress that RA medications (DMARDs) take weeks to months to work; they must not stop taking them just because they don't feel immediate pain relief. Advise on infection risks associated with biologics. Prior to any surgery with intubation, a cervical spine X-ray is mandatory to check for C1-C2 instability.
Follow-Up & Monitoring Schedule
Treat-to-target strategy: Assess disease activity using scores like DAS28 or CDAI every 1-3 months. For Methotrexate: monitor CBC, CMP (liver enzymes), and serum creatinine every 2-3 months. Screen for TB (Quantiferon-Gold) and Hepatitis B/C prior to starting any biologic.
Preventive Strategies
No absolute prevention, but avoiding smoking and maintaining good dental hygiene (preventing periodontitis) are the strongest modifiable factors for those with a family history.
With early aggressive DMARD therapy, clinical remission is achievable in 40-50% of patients, preventing severe deformities. However, without treatment, 50% of patients will have work disability within 10 years. Life expectancy is reduced by 3-10 years primarily due to cardiovascular disease.