I. Definition--a heterogeneous family of chronic inflammatory arthritides affecting both spinal and non-spinal joints with the following common features:

  1. Symptom onset is typically insidious and prior to 40y of age
  2. Involvement of spinal ("spondylitis") and sacroiliac (SI) joints with pain (usually "dull" in character) and stiffness (worst in morning, not improved with rest, often improved with exercise)
  3. When present, non-spinal involvement joint is usually asymmetric, migratory, or oligoarticular
  4. Tendon insertion sites may be inflamed (enthesopathy)
  5. "Sausage digits"
  6. Extra-articular features
    1. Anterior uveitis (usually acute & unilateral)
    2. Aortitis
    3. Aortic and mitral valve dilatation
    4. Pulmonary fibrosis
    5. Renal amyloidosis (rare)
    6. Constitutional symtpoms (fatigue, mild fever, anorexia)
    7. Cauda equina syndrome
    8. Atlantoaxial subluxation
  7. Male predominance (for some subsets)
  8. Usually negative for rheumatoid factor
  9. Strong association with Class I HLA antigens, e.g. HLA-B27
  10. Infectious agents appear to be involved in pathogenesis (for some subsets)

II. Specific syndromes

  1. Ankylosing spondylitis
    1. Epidemiology
      1. The most common spondyloarthropathy; Prevalence 0.1%
      2. Male: female 3:1
      3. Most common in people of European descent; Rare in people of African descent
      4. Usually presents in late teens to early adulthood
      5. Pain usually starts at SI joints and gradually moves cranially
      6. Often have SI joint tenderness
    2. Predominantly afects the spine; can get fusing of vertebrae
  2. Reiter's syndrome
    1. Often follows nongonococcal urethritis, esp. chlamydia
    2. Oligoarticular arthritis
    3. Often accompanied by conjunctivitis and mucocutaneous or skin lesions
    4. Usually self-limited, lasting 3-12mos
    5. Chronic symptoms occur in 15-20%
  3. Psoriatic arthritis
    1. Usually peripheral arthritis
    2. Seen in about 7% of pts with cutaneous psoriasis
    3. Usually accompanied by nail pitting
  4. Reactive arthritis
    1. Clinically similar to Reiter's
    2. Follows enteritis from Shigella, Salmonella, Yersinia, or Campylobactor
    3. Usually self-limited, lasting 3-12mos
    4. Chronic sx occur in 15-20%
  5. Enteropathic arthritis
    1. Associated with inflammatory bowel disease (20% get arthropathy; 10% get spondylitis)
    2. Arthropathy sx us. not correlated w/bowel sx
  6. "Undifferentiated spondyloarthropathy"
    1. For pts without evident coexisting psoriasis, enteric infection, or enteropathy and without clinical features of Reiter's or ankylosing spondylitis

III. Pathophysiologic features

  1. Mononuclear inflammation of synovium, periarticular bone, cartilage, and joint capsule
  2. Ossification of tendon entheses
  3. Radiographs may be normal but can show narrowing or irregularity of SI joint and late in the disease, squaring of vertebral bodies, osteitis of vertebral margins, and calcification of the annulus fibrosus ("bamboo spine").
  4. Lab abnormalities include increased ESR and CRP and occasionally, mild anemia

IV. Treatment

  1. Similar to treatment of Rheumatoid Arthritis: NSAIDs alone in mild cases (sulfasalazine if cannot tolerate NSAIDs), DMARD's when more severe, systemic steroids for brief periods in flares or chronically as a last resort
    1. Note that hydroxychloroquine in psoriatic arthritis may in rare cases lead to flare of cutaneous psoriasis
    2. TNF-alpha inhibitors (e.g. etanercept, infliximab) have been used to reduce symptoms
  2. Physical therapy for spine ROM

(Sources include Core Content Review of Family Medicine, 2012)