Rheumatoid Arthritis - MSK - Medbullets Step 1

Snapshot
A 36-year-old woman presents to her physician's clinic with pain and swelling in the hands and wrists. She reports morning stiffness that lasts for approximately 1 hour which later improves. She also states to be experiencing symptoms of depression and fatigue. On physican exam, there is decreased grip strength and 4/5 strength on wrist extension. There is tenderness to palpation and swelling of the proximal interphalangeal joints and metacarpophalangeal joints.
Introduction
Definition a chronic autoimmune disorder that primarily affects the joints and results in an inflammatory synovitis Epidemiology demographics sex more common in women age 30-50 years of age risk factors smoking Etiology environmental and genetic factors play a role Pathogenesis T- and B-cell response after a triggering event (e.g., infection in a genetically susceptible patient) eventually results in pannus formation and subsequent damage to the adjacent cartilage and bone Th1 cells release interferon-γ (IFN-γ) in order to activate macrophages and synovial cells Th17 cells secrete interleukin-17 (IL-17) in order to recruit monocytes and neutrophils synovial plasma cells produce antibodies against self antigens such as citrullinated peptides Genetics HLA-DR4 Associated conditions Sjogren syndrome Felty syndrome seropositive rheumatoid arthritis with neutropenia many patients have splenomegaly Caplan syndrome seropositive rheumatoid arthritis with pneumoconiosis Prognosis certain patients with early rheumatoid arthritis may achieve remission
Presentation
Symptoms fatigue and depression morning stiffness that lasts > 1 hour pain, stiffness, and/or swelling of the joint such as the metacarpophalangeal (MCP) joints proximal interphalangeal (PIP) joints metatarsophalangeal (MTP) joints Physical exam anemia of chronic disease weight loss decreased grip strength palmar erythema subcutaneous (rheumatoid) nodules splenomegaly in cases of Felty syndrome ulnar deviation of the fingers swan neck deformity bouttoniere deformities

Imaging
Radiography indications can be obtained during the initial workup to have a baseline to compare to when following disease progression can be performed of the neck to rule out odontoid ligament laxity modality hands, wrists, and feet findings diffuse osteopenia joint space narrowing in the carpal, metacarpal, phalangeal, and interphalangeal joints periarticular bony erosions ulnar deviation of the fingers
Studies
Labs rheumatoid factor (RF) antibody testing RF is an IgM antibody that targets the Fc portion of IgG anti-CCP antibody testing more specific for rheumatoid arthritis erythrocyte sedimentation rate (ESR) levels typically elevated caused by interleukin 1, interleukin 6, and tumor necrosis factor alpha C-reactive protein (CRP) levels typically elevated Diagnostic criteria diagnosis is based on clinical presentation and laboratory studies

Differential

Systemic lupus erythematous
Psoriatic arthritis
Scleroderma
Polymyalgia rheumatica
Gout

Treatment

Conservative
- education, exercise, physical therapy, vaccinations, smoking cessation, and counseling
  - indication
    - a component of treatment for patients with rheumatoid arthritis
Pharmacologic
- disease-modifying antirheumatic drugs (DMARDs)
  - indications
    - used to prevent, stop, or retard disease-associated damage
  - medications
    - methotrexate
      - typically the initial DMARD used
    - tumor necrosis factor (TNF) inhibitor such as
      - etanercept
      - adalimumab
    - leflunomide
    - sulfasalazine
    - hydroxychloroquine
- nonsteroidal antiinflammatory drugs (NSAIDs) and/or glucocorticoids
  - indications
    - initially given for symptomatic control while waiting for DMARD response
Operative
- joint replacement surgery
  - indication
    - in patients with severe joint damage or failure to respond to conservative and medical therapy

Complications

Hand deformities
Atlantoaxial subluxation
Popliteal cyst