Spondyloarthritis is an umbrella term for a group of chronic arthritis-like diseases affecting the joints of the spine and the sacroiliac region. The sacroiliac region includes the pelvis and the lower spine.
Healthcare professionals classify spondyloarthritis into different subtypes. Some subtypes cause widespread inflammation that can affect multiple organs or systems in the body.
This article describes what spondylitis is and how it differs from a similar condition called spondylosis. We then describe the different types of spondyloarthritis and their associated causes and symptoms. Finally, we provide information on the diagnosis and treatment of spondyloarthritis.
Spondyloarthritis is an umbrella term for a group of chronic arthritis-like diseases affecting the joints of the spine and the sacroiliac region.
All types of spondylitis involve inflammation of the joints, tendons, and ligaments. Tendons are connective tissues that attach muscles to bones, while ligaments are connective tissues that attach bones to other bones.
Inflammation of the joints can cause bones to fuse and trigger excessive bone growth in the spine. Severe cases can cause excessive curvature of the spine.
Spondylitis and spondylosis are similar conditions that can cause both hip pain and back pain. However, the two conditions have different characteristics and causes.
Spondyloarthritis is a condition in which the immune system attacks the joints, causing inflammation, bone fusion, and excessive bone formation.
Certain types of spondyloarthritis tend to develop in adolescents and young adults.
Spondylosis is a type of arthritis related to aging and general wear and tear of the spine. It occurs when the joints and discs of the spine degenerate. Osteophytes, which are bony spurs that grow on the backbones or individual vertebrae, can also be the cause.
Spondylosis tends to affect older people. More than 85% of people over 60 have it.
Doctors can use two different classification systems to diagnose spondyloarthritis: the traditional system and the newer system. According to the Spondylitis Association of America, the traditional system recognizes six types of spondyloarthritis, while the new system consists of two larger categories encompassing all types of spondylitis.
Traditional classifications of spondyloarthritis
The traditional spondyloarthritis classification system classifies spondyloarthritis into six types. These are:
Ankylosing spondylitis (AS) is a form of chronic joint inflammation that primarily affects the spine. The term “ankylosis” refers to joint stiffness resulting from injury or disease. In AS, a fusion of the spinal vertebrae causes stiffness and limited movement of the spine.
AS usually begins during adolescence or early adulthood.
Symptoms of AS can develop slowly over time and can come and go. They may include:
Experts do not know the exact cause of AS. However, 9 out of 10 people with AS carry the human leukocyte antigen B27 (HLA-B27) gene.
This suggests that the gene may predispose a person to AS, but does not mean that a person with the gene will develop the disease. Researchers estimate that 8 in 100 people have the HLA-B27 gene, but most do not develop AS.
Reactive arthritis (AER) is a type of inflammatory arthritis that usually shows up several days or weeks after a gastrointestinal infection or sexually transmitted infection (STI).
Experts sometimes describe ReA as a triad of inflammatory conditions, although
Symptoms of ReA can include:
- Arthritis: Swelling and pain in the joints.
- Conjunctivitis: Inflammation of the eyes with a sticky discharge.
- Urethritis: Genital and bladder inflammation and pain when urinating.
Reactive arthritisUsually the result of an intestinal infection or certain STIs. People can also develop ReA as a result of glandular fever or erythema infectiosum.
In ReA, the immune system overreacts to the infection and begins to attack healthy tissue. This leads to inflammation.
Research also links reactive arthritis to the HLA-B27 gene. Scientists believe that
Psoriatic arthritis (PsA) is a chronic inflammatory disease that affects the joints and the areas where ligaments and tendons attach to bones. The disease is associated with inflammatory psoriasis of the skin. For many people, PsA develops about 10 years after psoriasis, but some people develop PsA first or without ever having psoriasis.
Psoriatic arthritis can occur at any age, but typically affects people between the ages of 30 and 50.
Symptoms of PsA can include:
A person can develop PsA in a joint as a result of an injury. The disease can also be linked genetically. Researchers estimate that at least 10% of the population inherits one or more genes that predispose a person to psoriasis.
Enteropathic arthritis (EnA) is a type of chronic inflammatory arthritis associated with inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn’s disease (CD). About 1 in 5 people with UC or MC also develop EnA.
Enteropathic arthritis typically affects the joints of the arms, legs, and spine.
Symptoms of EnA can include those related to IBD, as well as those related to arthritis. Examples include:
Experts do not know the precise cause of EnA, but believe the disease is associated with inflammation of the intestine. Chronic inflammation of the gut can allow bacteria to enter the damaged intestinal wall and move through the bloodstream. The body’s reaction to these bacteria can cause additional inflammation and pain.
Enteropathic arthritis is also associated with the “HLA-B27” gene.
Juvenile spondylitis is a chronic inflammatory arthritis that begins in the elderly
Symptoms of JSpA can
Experts do not know the precise cause of JSpA. However, as with spondyloarthritis in adults, children with the disease often carry the HLA-B27 gene.
Undifferentiated spondyloarthritis (USpA) is a diagnosis that a doctor can make when a person has a variety of symptoms that doctors cannot categorize as a specific rheumatoid disorder.
Symptoms of USpA vary but can include:
- persistent pain in the lower back, which develops before age 45
- joint pain in small and large joints
- Heel pain
- swelling of the hands and feet
- general rigidity
- eye inflammation
- bumpy rash
- symptoms of the urinary tract and genitals, such as pain and discharge
- intestinal inflammation
New categorizations of spondyloarthritis
The new spondyloarthritis classification system classifies spondyloarthritis into two main types depending on where the disease occurs in the body. The two types are peripheral spondyloarthritis and axial spondyloarthritis.
Peripheral spondyloarthritis (pSpA) usually causes inflammation of the joints and tendons outside the spine and the sacroiliac joints. The disease usually affects the following areas:
A person with pSpA may have dactylitis, which is inflammation of the toes and fingers, or enthesitis, which is inflammation in the areas where ligaments and tendons attach to bones.
This category includes the following forms of spondyloarthritis:
- reactive arthritis
- enteropathic arthritis
- undifferentiated arthritis
Axial spondyloarthritis (AxSpA) causes inflammation and pain in the pelvis, spine, or both. This category covers a wide range of types of spondyloarthritis and includes people with and without fusion and damage to the sacroiliac joint.
There is no definitive test to diagnose spondylitis. Doctors will do a physical exam that includes questions about a person’s symptoms and medical history. They will also ask if the person has a family history of autoimmune diseases, including psoriasis and spondyloarthritis.
Diagnosis may also involve the following:
- blood tests
- imaging tests, such as:
- genetic test for the HLA-B27 gene
There is no cure for spondylitis. However, treatments can help manage the condition and relieve symptoms.
Treatment options may include the following:
- medicines to reduce inflammation and pain, such as:
- physical therapy, which may include massages and spinal manipulations to improve and maintain flexibility of the spine
- exercises to relieve joint pain and stiffness
- breathing exercises to ensure normal chest expansion
In some cases, doctors may also recommend surgery to repair severely damaged joints or correct the extreme curvature of the spine. However, surgery for spondyloarthritis is rare compared to other therapeutic approaches.
A person can use complementary therapies alongside standard spondyloarthritis treatments for additional symptom relief. These therapies can
Spondylitis refers to a group of inflammatory diseases such as arthritis. The traditional spondyloarthritis categorization system recognizes six subtypes of spondyloarthritis. The new categorization system recognizes two larger subtypes based on the area of the body affected by the disease.
There is no official diagnostic test for spondyloarthritis. Instead, a doctor can use a combination of tests to diagnose the condition. These can include blood tests, imaging tests, and genetic tests.
Although there is no cure for spondylitis, treatments can help manage the condition and relieve symptoms. Treatment options include medication, physical therapy, and exercise. Some people may also wish to try complementary therapies such as massage, relaxation techniques, and acupuncture in addition to standard treatments.