Rheumatoid arthritis

Definition
Rheumatoid arthritis is a chronic, systemic, autoimmune inflammatory disease that primarily targets synovial joints, leading to progressive joint damage, deformity, and disability. It may also cause extra-articular manifestations affecting skin, eyes, lungs, cardiovascular system, and other organs.

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Causes & Pathophysiology

• Autoimmune mechanism: Immune system attacks synovial membrane, causing synovitis

• Genetic factors: HLA-DR4 and HLA-DR1 association

• Environmental triggers: Smoking, infections, periodontal disease

• Pathogenesis: Inflammatory cytokines (TNF-α, IL-1, IL-6) drive pannus formation → cartilage destruction and bone erosion

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Risk Factors

• Female sex (3× more common than in men)

• Age 30–50 years

• Family history of RA

• Smoking

• Obesity

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Clinical Features

Joint Symptoms

• Symmetrical pain, swelling, and stiffness (especially small joints of hands and feet)

• Morning stiffness >1 hour

• Warmth and tenderness over joints

• Progressive joint deformities (ulnar deviation, swan-neck, boutonnière)

Extra-Articular Manifestations

• Rheumatoid nodules

• Interstitial lung disease

• Pericarditis, vasculitis

• Scleritis, episcleritis

• Anaemia of chronic disease

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Diagnosis

Laboratory Tests

• Rheumatoid factor (RF) — positive in ~70–80%

• Anti-cyclic citrullinated peptide antibodies (anti-CCP) — high specificity

• ESR and CRP — elevated in active disease

• Normocytic, normochromic anaemia

Imaging

• X-rays: Joint space narrowing, marginal erosions, osteopenia

• Ultrasound/MRI: Synovitis and early erosions

Classification Criteria (ACR/EULAR 2010)

• Joint involvement

• Serology (RF, anti-CCP)

• Acute phase reactants (ESR, CRP)

• Duration of symptoms

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Treatment

General Measures

• Patient education, exercise, joint protection, smoking cessation

• Multidisciplinary care (rheumatologist, physiotherapist, occupational therapist)

Pharmacological

1. Disease-Modifying Antirheumatic Drugs (DMARDs) — start early (“treat to target” strategy)

   • Methotrexate: 7.5–25 mg orally/weekly, with folic acid supplementation

   • Sulfasalazine: 500 mg–1 g twice daily

   • Leflunomide: 10–20 mg daily

   • Hydroxychloroquine: 200–400 mg daily

2. Biologic DMARDs (for inadequate response to conventional DMARDs)

   • TNF-α inhibitors: etanercept, adalimumab, infliximab

   • IL-6 inhibitors: tocilizumab

   • B-cell depletion: rituximab

   • T-cell costimulation blocker: abatacept

3. Janus Kinase (JAK) Inhibitors

   • Tofacitinib, baricitinib, upadacitinib

4. Glucocorticoids

   • Low-dose prednisolone (≤10 mg/day) for short-term symptom control or flares

5. NSAIDs

   • For pain relief and stiffness (not disease-modifying)

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Complications

• Joint destruction and deformity

• Cervical spine instability (atlantoaxial subluxation)

• Cardiovascular disease

• Lung involvement

• Osteoporosis from inflammation and corticosteroid use

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Quick-Reference Clinical Chart — Rheumatoid Arthritis

Feature	Details
Definition	Chronic autoimmune inflammatory arthritis affecting synovial joints
Key Symptoms	Symmetrical joint pain/swelling, morning stiffness >1 hr
Extra-Articular Signs	Nodules, lung disease, vasculitis, ocular inflammation
Labs	RF+, anti-CCP+, ↑ESR/CRP
Imaging	Erosions, joint space narrowing
First-Line DMARD	Methotrexate (weekly) + folic acid
Biologics	TNF-α inhibitors, IL-6 inhibitors, rituximab, abatacept
Other Drugs	Sulfasalazine, hydroxychloroquine, leflunomide, JAK inhibitors
Adjuncts	NSAIDs, glucocorticoids for flares
Prevention	Early aggressive treatment to achieve remission
Prognosis	Variable; early treatment improves outcomes