-IBIS-1.5.0-
tx
musculoskeletal system
ankylosing spondylitis
diagnoses

definition and etiology

definition:
A chronic and generally progressive inflammatory arthritic disease affecting the spinal joints and adjacent connective tissues. Also called "Marie Strumpell disease"

etiology:
This appears to be a disease mainly of young men aged 10-30 years old. It seems to have a genetic component, as it is seen in male relatives and especially in patients with histocompatibility complex HLA-B27 (who have a 300 times greater risk of developing AS, particularly in white men). The etiology is unknown. It is seen throughout the world.

signs and symptoms

Onset is gradual and insidious.

initial symptoms:
• Low back pain: especially in sacroiliac and lumbar areas, may appear to be sciatic pain.
• Stiffness on awakening.
• Nocturnal pain and stiffness causing insomnia.

advanced disease:
• Pain spreads up spine often into the mid-back and neck.
• Hips and shoulders may also be involved: in a third of patients.
• Fatigue.
• Weight loss and anorexia.
• Slight anemia.
• Muscle stiffness or cramping.
• Pain on breathing or decreased ability in draw in deep breath.
• Limited mobility of spine, bent-over stance, increased dorsal kyphosis, waddling gait.
• Normal neurologic examination.
• Chronic iritis.

joints affected:
• Sacroiliac: nearly always.
• General spinal (neck to lumbar): always, eventually.
• Hips: often.
• Shoulders: often.
• Peripheral joints: rarely.

lab findings:
• X-ray: flattened lumbar curve; blurred bony margins; decreased expansion of spine with flexion and extension; syndesmophytes (bony growths); fusion of joints/spine: leads to "bamboo spine" in severe cases.
• Possibly increased ESR (< 80%).
• Mild to moderate hypochromic anemia.
• (+) HLA-B27 (95%).
• (+) ANA (low).
• Increased complement activity.
• Increased WBC.
• Occasional (+) RF.

course and prognosis

Conventional treatment does not stop the progression of the disease. Stretching exercises and careful adherence to correct posturing are absolutely required to maintain as much mobility as possible over time. Occasionally surgery is used to replace a badly affected joint or to straighten the spine.

differential diagnosis

• Reiter's disease.
• Psoriatic spondyloarthritis.
• Yersinia arthritis.
• Spondyloarthritis associated with inflammatory bowel disease.
• Rheumatoid arthritis.


footnotes