What is Ankylosing Spondylitis?

What you need to know about Spondyloarthritides

Spondyloarthritides are a group of arthritic diseases that share several common features. They can cause inflammation of the spine; however, other joints may be affected. The tendon and ligament tissue near the spine or joint is also involved. A high percentage of people with these diseases share a similar gene called HLA B27. Finally, many patients also have inflamed areas in the eye, bowel, genital tract or skin.

The spondyloarthropathies include:

  • Ankylosing spondylitis
  • Psoriatic arthritis
  • Reactive arthritis/Reiter's syndrome
  • Enteropathic arthritis
  • Undifferentiated: Patients with features of more than one disease who do not fit in the defined categories above

What is Ankylosing spondylitis (AS)?

AS is a chronic, systemic, inflammatory disease of the joints and ligaments of the spine. Other joints may be involved. This typically results in pain and stiffness in the spine. The disease may be mild to severe. The bones of the spine may fuse over time causing a rigid spine. Early diagnosis and treatment may help control the symptoms and reduce debility and deformity.

Who gets ankylosing spondylitis (AS)?

The onset is typically in late adolescence to early adulthood. It is rare for AS to begin after age 45. The disease is more common in men and in Caucasians. The incidence is 1 in 1000 persons. About 90% of people with AS have the HLA B27 gene.

What is reactive arthritis (ReA)?

Reactive arthritis is a non-infectious inflammation of one or several joints. It may be self-limited, relapsing or chronic. The condition sometimes follows an infection of the gastrointestinal or genitourinary system. There may be other non-joint features such as eye, genital tract, bowel or skin inflammation.

The term Reiter's Syndrome is an older term that most rheumatologists have now replaced with Reactive Arthritis. Reiter's Syndrome was a term originally used to refer to a syndrome of non-infectious eye, genital and joint inflammation following a previous bowel or genital bacterial infection. All of these features are rarely seen together.

Who gets reactive arthritis?

ReA may follow an infection of the genital tract or bowel, but this is not always identified. It is more common in men and Caucasians. ReA is rare after the age of 50. The disease is associated with the HLA B27 gene in 50 to 80% of patients.

What is enteropathic arthritis?

Enteropathic arthritis is peripheral joint or spine disease associated with inflammatory bowel disease (IBD), such as Crohn's Disease or Ulcerative Colitis.

Who gets enteropathic arthritis?

Enteropathic arthritis is seen in up to 10 to 20% of those with IBD. It is more common in juveniles and young adults. The male to female ratio is equal.

What causes ankylosing spondylitis (AS)?

The cause of AS is unknown although there appears to be some genetic component. AS is associated with the HLA B27 gene but it is unclear why. The gene is seen in about 8% of normal Caucasians. There are no known infectious or environmental causes.

What are the signs and symptoms of ankylosing spondylitis (AS)?

Early on, there is pain and stiffness in the buttocks and low back due to sacroiliac joint involvement. Over time, the symptoms can progress up the spine to involve the low back, chest and neck. Ultimately, the bones may fuse together causing limited range of motion of the spine and limiting one's mobility. Shoulders, hips and sometimes other joints may be involved. AS may affect tendons and ligaments. For example, the heel may be involved with Achilles tendonitis and plantar fasciitis. Since it is a systemic disease, patients can get fever and fatigue, eye or bowel inflammation, and rarely, there can be heart or lung involvement. AS is typically non life-threatening. Usually, it is a slowly progressive disease. Most people are able to work and function normally.

What causes reactive arthritis?

The cause of ReA is unknown. It is associated with the HLA B27 gene, but it is unclear why. It is also unclear why ReA is sometimes associated with infection. (Bacterial infections of genital tract with Chlamydia or gastrointestinal tract with Shigella, Salmonella, or Campylobacter).

What are the signs and symptoms of reactive arthritis?

ReA may follow several weeks after a genital tract or bowel infection. The patient may have acute swelling, pain and redness in one or more joints. Typically, it is more common in the lower extremity joints. During the joint symptoms, one may also have non-infectious genital tract, skin or eye inflammation. ReA patients may have tendonitis, especially of the heel. There may be spine involvement (like ankylosing spondylitis). Traditionally, ReA is self-limited to 3 to 12 months, but up to 50% may have relapsing or chronic disease. The disease is not life threatening, and most people are able to work and function normally.

What causes enteropathic arthritis?

The cause is unknown.

What are the signs and symptoms of enteropathic arthritis?

The arthritis typically occurs after the bowel disease is well established. Rarely, the arthritis can start before IBD is diagnosed. There is pain and swelling in one or more joints. Typically, the arthritis occurs in the lower extremity joints. The arthritis may mirror the activity of the bowel disease. There may also be spine involvement (like ankylosing spondylitis). The HLA B27 gene is seen in up to 50% with spine involvement. The spondylitis (spine involvement) is less likely to correlate with the bowel disease activity. Patients may have other systemic symptoms such as fever, skin or eye inflammation, and oral ulcers. Enteropathic arthritis rarely causes joint destruction, deformity or significant disability.