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Symptoms of Undifferentiated Spondyloarthritis

According to Dr. Herbert Kaplan, MD (retired) pain may be the only complaint of people with undifferentiated spondyloarthritis. Most people with undifferentiated spondyloarthritis (USpA) have one or more of the following symptoms:

  • Inflammatory back pain
  • Unilateral or alternating buttock pain
  • Enthesitis - inflammation where a tendon or ligament attaches to the bone
  • Peripheral arthritis – arthritis in the large joints of the limbs
  • Arthritis of the small joints
  • Swollen fingers or toes
  • Heel pain
  • Fatigue
  • Iritis

Onset of the disease is often insidious and, even after years of inflammation, calcification of the sacroiliac joints (the joints where the spine meets the pelvis) is often absent or mild on routine X-rays.

USpA is more common in females than males, and only 20 to 25 percent of people with USpA are HLA-B27 positive.

Some people with undifferentiated spondyloarthritis later develop symptoms of the other forms of spondylitis, such as ankylosing spondylitis (AS) or psoriatic arthritis, while others will continue to have chronic, but generally not severe symptoms, and remain "undifferentiated."

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