Spondyloarthritis (SpA) is an umbrella term for several types of inflammatory arthritis that can cause chronic back pain and stiffness.1 Although SpA and fibromyalgia have different causes and treatments, they share many common features, including chronic pain, fatigue, sleep problems, decreased quality of life, anxiety, and depression. Because of these commonalities, the two conditions can often overlap and cause misdiagnosis, which leads to a delay in proper treatment and relief from symptoms.2
In a 2020 survey of 301 people with fibromyalgia, 44 also had a diagnosis of axial spondyloarthritis, a type of SpA. Of those 44 individuals, about half believed they should have received an earlier diagnosis. Thirty-nine percent reported their diagnosis was delayed because doctors believed their symptoms were caused only by fibromyalgia.3
Take the quiz to see if your symptoms could be caused by spondyloarthritis.
Spondyloarthritis mostly affects the spine and sacroiliac joints (joints that connect to the pelvic bone), but can also develop in other joints, tendons, and ligaments. SpA is characterized by inflammation at the site where a tendon or ligament attaches to a bone (also called an enthesis). Over time, inflammation can cause chronic back pain and stiffness.1
Typical symptoms of spondyloarthritis include:4
Typical symptoms of fibromyalgia include:5
Both spondyloarthritis and fibromyalgia are considered rheumatic disorders associated with chronic pain, fatigue, and weakness. It has been reported that as many as 21 percent of women later diagnosed with SpA were first told they had fibromyalgia. Ongoing pain, sleep disturbances, and fatigue are common symptoms of SpA and fibromyalgia.2
While spondyloarthritis is considered a type of arthritis, fibromyalgia is classified as a nervous system disorder and affects the way pain is decoded by the central nervous system.2
Typically, people with SpA experience pain in the lower back and buttocks, while people with fibromyalgia typically experience widespread pain affecting the soft tissue and muscles.2,6 As is common with inflammatory pain, pain from SpA is often worse after periods of inactivity, such as after sleep, but improves after activity.4 Fibromyalgia pain is not associated with inflammation, and sometimes gets worse with activity.6
The differences between the two conditions may be less obvious in women — women with SpA are more likely to have widespread pain rather than pain specifically in the lower back.7 SpA is also more prevalent in men, while fibromyalgia is more prevalent in women.7,8 The different SpA symptoms in men and women, the overlap between SpA and fibromyalgia symptoms, and the lopsided gender prevalence can lead to delayed diagnosis or misdiagnosis in women with SpA.7
Both spondyloarthritis and fibromyalgia may be treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and physical therapy, but from there treatment approaches diverge.9-11 Fibromyalgia is often treated with antidepressants and antiseizure drugs.9 SpA can be treated with corticosteroids, methotrexate, and biologic therapies.10
Learn more about SpA by reading What Is Spondyloarthritis?
Take the quiz to see if your symptoms could be from inflammatory back pain, such as SpA.
A British study of approximately 1,500 people with axial spondyloarthritis found that 20 percent of participants also met the criteria for fibromyalgia.12 Having SpA or other types of arthritis can increase your chances of developing fibromyalgia later.2
Having both SpA and fibromyalgia together can increase the severity of symptoms and diminish quality of life. Therefore, it is suggested that people who are experiencing symptoms of fibromyalgia or SpA should be screened for both so action can be taken to treat all symptoms at the same time.12
You can use this Doctor Discussion Guide to lead the conversation about spondyloarthritis symptoms.
By joining MyFibroTeam, you gain a community of nearly 275,000 people living with fibromyalgia.
How have symptoms of fibromyalgia and spondyloarthritis affected your life? Share your experience in the comments below or on MyFibroTeam. Your story may help others on their path to pain relief.