What Is Undifferentiated Spondyloarthropathy?

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Undifferentiated spondyloarthritis (USpA) is a term used to describe the symptoms of spondylitis in individuals who do not meet the definitive criteria for a diagnosis of ankylosing spondylitis (AS) or another spondyloarthropathy (e.g., psoriatic arthritis).

It is most commonly diagnosed in individuals who have a variety of symptoms that cannot be classified as a specific disorder. For example, a person may have heel pain and knee pain without the common intestinal symptoms or back pain found in those diagnosed with AS.

These individuals are often given a diagnosis of USpA. Over time, some individuals with an initial diagnosis of USpA go on to develop more symptoms and thus are diagnosed with a more well-defined form of spondylitis. 

women holding lower back in pain

Delmaine Donson / E+ / Getty Images

Symptoms

Symptoms of undifferentiated spondyloarthropathy vary from person to person. Sometimes the only symptom a person with USpA may experience is pain. Others may experience more symptoms, including: 

  • Arthritis in large joints of the limbs 
  • Back pain
  • Buttock pain on one or both sides
  • Enthesitis: Inflammation and swelling where a tendon or ligament attaches to bone
  • Fatigue 
  • Heel pain
  • Iritis: Inflammation and swelling in the eye
  • Pain and swelling and/or arthritis in the fingers or toes

Undifferentiated spondyloarthropathy causes symptoms that aren’t as specific as other types of arthritis. It is more commonly diagnosed in women. Some people go on to develop symptoms of a more identifiable form of spondylitis, such as psoriatic arthritis or ankylosing spondylitis. Others may continue to have chronic symptoms of USpA.  

Diagnosis

Undifferentiated spondyloarthritis can be difficult to diagnose. USpA is the least well known in the group of spondylitis conditions, and is unrecognized by some healthcare providers. Some patients are initially incorrectly diagnosed with fibromyalgia, as the symptoms of both diseases may present similarly.

Visiting a healthcare provider with expertise in rheumatoid conditions—such as a rheumatologist—is important for an accurate diagnosis of USpA. In order to get a diagnosis of USpA, your healthcare provider may suggest the following: 

Physical Exam

If your healthcare provider suspects you have undifferentiated spondyloarthropathy, the first thing they will do is perform a physical exam. This includes your healthcare provider reviewing your symptoms and asking about your medical history and family medical history background.

The physical examination involves your healthcare provider examining your spine, including the cervical (neck), thoracic (midspine), and lumbar region (lower spine). 

Lab Work

In addition to the physical examination, your healthcare provider may order lab work such as blood tests that look for a variety of factors, including antibodies or immune system responses.

Your healthcare provider may also order a test to determine if you carry the human leukocyte antigen B27 (HLA-B27) gene. Approximately 80% to 95% of people with ankylosing spondylitis have this particular gene.

Fewer people with USpA carry the gene. Because it is present in up to 7% of the general population, having this genetic marker does not equate to a diagnosis.

Imaging Tests

Your healthcare provider may also order imaging tests to diagnose undifferentiated spondyloarthropathy. Diagnostic imaging is important for diagnosing and monitoring all spondyloarthropathies. These imagining tests may include: 

  • X-rays: These are commonly taken of the pelvic region, where the sacroiliac joint is located to look for joint erosion. Subtle joint erosion is not always visible in X-rays of those with USpA. 
  • Magnetic resonance imaging (MRI): People with spondyloarthropathies, including USpA, typically experience pain in the sacroiliac joints (hip bones). MRI can diagnose sacroiliitis indicative of USpA. MRI can also be used to scan other parts of the body and may detect soft tissue, tendon, and joint abnormalities.

Finding evidence of inflammation in the sacroiliac joints on X-ray or MRI is often the most helpful modality in confirming a diagnosis of spondylarthopathy.

Treatment

There is currently no cure for undifferentiated spondyloarthropathy, but with proper management of the disease, patients can live fully productive lives. The primary treatments for USpA generally include medication, physical therapy, and exercise. Some patients also find relief by applying heat and/or ice to help reduce joint pain.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Most USpA patients will begin treatment by taking nonsteroidal anti-inflammatory (NSAID) medications such as ibuprofen or a prescribed NSAID, such as diclofenac. NSAIDs help temporarily reduce pain and inflammation.

Biologics

When NSAIDs alone are not enough to provide relief, healthcare providers may prescribe drugs known as biologics. These are either given in a healthcare provider's office through infusion in a vein, or by self-injection.

There are no biologics that are approved by the U.S. Food and Drug Administration (FDA) for undifferentiated spondyloarthropathy, although they are approved for the treatment of specific spondyloarthropathies such as ankylosing spondylitis, inflammatory bowel disease-associated arthritis, and psoriatic arthritis.

While it is felt that biologics may help patients with this disorder, the use of these medications is considered "off label" because they are not FDA approved for undifferentiated spondyloarthropathy.

There are two groups of biologics. Tumor necrosis factor inhibitors (TNFi), such as Humira, Enbrel, and Remicade are typically the first group of biologics healthcare providers recommend for patients; they bind and neutralize TNF in the body, reducing inflammation. 

The second group of biologics are interleukin 17 inhibitors, which are a newer group of drugs. They include Cosentyx and Taltz.

Corticosteroids

Corticosteroids may be used to reduce inflammation and joint pain. These may be taken as an oral medication or given as injections locally, injected directly into the joint(s) where you are experiencing pain. Corticosteroids are typically taken on a short-term basis. 

Exercise

Exercise is very important to the management of undifferentiated spondyloarthropathy. Regular movement helps relieve stiffness and pain. If you are experiencing a flare of pain, light exercise such as a walk can be effective.

Stretches can be done both sitting and lying down if your pain is too intense. There is no "best" form of exercise for USpA patients; all exercise is beneficial, provided it is low-impact (e.g., walking and swimming) and done on a regular basis. 

Exercise may be done alone or with the help of a physical therapist, who can pair you with a suitable program of exercise and stretching. Check with your healthcare provider before beginning an exercise program. Start slowly, and gradually build up your stamina and strength. Do not push yourself to the point of pain. 

Surgery 

In some patients who do not get relief from medications or exercise, surgery may be beneficial. This is typically the last line of treatment in USpA patients.

Prognosis

Individuals living with USpA generally have a good prognosis. Some people with USpA will experience intermittent symptoms, requiring medication or other treatments only occasionally.

Others will have chronic, though not severe, symptoms requiring regular medication and treatment. With proper management of the disease, individuals living with USpA are able to live full lives. 

Living With USpA

One of the best ways to take care of yourself if you have undifferentiated spondyloarthropathy is to take a proactive role in your treatment. Self-management of the disease can go a long way in helping you live a happy and productive life.

Making healthy lifestyle choices, such as eating a healthy, balanced diet, taking your medication as directed, and getting regular exercise, are all helpful ways to manage the disease. Make regular appointments with your healthcare provider and inform them of any changes in your physical and mental health, and of any side effects of medications you are taking. 

Complementary therapies such as massage therapy, acupuncture, and hot/cold therapy, can help to reduce pain and stress. 

Many people living with undifferentiated spondyloarthropathy don’t just experience the physical effects of the disease. Many have emotional effects as well—pain can be debilitating and cause feelings of depression and sadness.

You may benefit from the support of others such as friends, family, and other USpA patients. Support groups for those living with undifferentiated spondyloarthropathy are available online and in-person. Check with your healthcare provider to ask about support groups in your area.

A Word From Verywell

Despite the physical and emotional impact that undifferentiated spondyloarthropathy can have on your day-to-day life, most people are able to live a full life with the condition. With the right combination of medical care, medication, and self-management through healthy lifestyle choices, the disease can be managed.

If you smoke, try to quit, as smoking has a negative impact and may worsen your condition. Speak with your healthcare provider about any questions you have about potential treatments and management of the disease.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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