Diagnosis

Rheumatoid arthritis

Etiology

Cause [ud4]

• Unknown

• Possible theory: Environmental trigger in a genetically predisposed host

  1. Genetically susceptible individuals (carrier of HLA-DR4 or HLA-DR1) AND

  2. External trigger (cigarette smoking, infection, or trauma)

Pathophysiology

1. Autoantibodies --> Inflammation

   • CD4 T cells, mononuclear phagocytes, fibroblasts, osteoclasts, neutrophils, B cells (RF), TNF-alpha, IL-1, IL-6, IL-8, TGF-ß, FGF, and PDGF

2. Arthritis --> synovial cell hyperplasia and cartilage/bone/tendon/ligament destruction

3. Chronic arthritis --> loss of cartilage and bone erosions

4. Distribution:

   • Joints: MCP, wrist, PIP, knee, MTP, shoulder, ankle, cervical spine, hip, elbow), synovial hypertrophy (pannus)

   • Extra-articular manifestations: Skin, heart, lungs, GI, vascular, hematologic, neurologic and eyes

Risk factors [rtx]

• Genetics

• Tobacco

• Red meat intake

• Vitamin D deficiency

• Excessive coffee consumption

• High salt intake

Complications [ud4]

• Osteopenia and osteoporosis

• Progressive deformity/disability

• Venous thromboembolic disease

• Anemia of chronic disease

• Felty syndrome (splenomegaly and neutropenia)

• Secondary Sjögren syndrome

• Inflammatory eye disease

• Rheumatoid vasculitis

• Pulmonary manifestations: Pleuritis, bronchiolitis, and interstitial lung disease

• Coronary artery disease

• Lymphoma

Epidemiology

Incidence per 100.000 [onp][kqf][nm8][zme][qbc]

Approach

• Blood test: Erythrocyte sedimentation rate, CRP, complete blood count, Rheumatoid factor, Antinuclear antibody, Anti−cyclic citrullinated peptide antibody (anti-CCP) [rtx]

• X-ray: Hands, wrists, knees, feet, elbows, shoulders, hips, cervical spine

• MR: cervical columna

• Ultrasound of joints

• Arthrocentesis: microscopy, gram stain, cell count, culture, biopsy

Diagnostic criteria: 2010 ACR/EULAR Classification Criteria [rtx][ud4]

1. Joint involvement:

   • 2-10 large joints = 1 point

   • 1-3 small joints (MCP, PIP, wrist joints) = 2 points

   • 4-10 small joints = 3 points

   • >10 joints = 5 points

2. Serology test results:

   • Low-positive RF or low-positive anti-CCP = 2 points

   • High-positive RF or high-positive anti-CCP = 3 points

3. Acute-phase reactant test results: Elevated CRP or ESR = 1 point

4. Duration of signs and symptoms: >6 weeks = 1 point

Score of ≥6 is classified as definite RA

Treatment

1. Conservative nonpharmacologic, nonsurgical therapies: [rtx]

   • Heat and cold therapies

   • Orthotics and splints

   • Therapeutic exercise

   • Occupational therapy

   • Adaptive equipment

   • Joint-protection education

   • Energy-conservation education

2. Nonbiologic disease-modifying antirheumatic drugs (DMARDs): [rtx]

   • Hydroxychloroquine

   • Azathioprine

   • Sulfasalazine

   • Methotrexate

   • Leflunomide

   • Cyclosporine

   • Gold salts

   • D-penicillamine

   • Minocycline

3. Biologic tumor necrosis factor (TNF)–inhibiting DMARDs: [rtx]

   • Etanercept

   • Infliximab

   • Adalimumab

   • Certolizumab

   • Golimumab

4. Biologic non-TNF DMARDs include the following: [rtx]

   • Rituximab

   • Anakinra

   • Abatacept

   • Tocilizumab

   • Sarilumab

   • Tofacitinib

   • Baricitinib

   • Upadacitinib

5. Other drugs used therapeutically include the following: [rtx]

   • Corticosteroids

   • Nonsteroidal anti-inflammatory drugs (NSAIDs)

   • Analgesics

6. Surgical treatments include the following: [rtx]

   • Synovectomy

   • Tenosynovectomy

   • Tendon realignment

   • Reconstructive surgery or arthroplasty

   • Arthrodesis

Differential diagnoses

Carpal tunnel syndrome, Episcleritis, Fibromyalgia, Gout, Juvenile rheumatoid arthritis, Lyme disease, Osteoarthritis, Osteoporosis, Polymyalgia rheumatica, Psoriatic arthritis, Pyoderma gangrenosum, Reactive arthritis, Rheumatic fever, Sarcoidosis, Septic arthritis, Sjogren syndrome, Systemic lupus erythematosus, Uveitis