Man holding lower back, back pain

Fibromyalgia, a disorder that affects and amplifies the ways the brain feels pain, can “mask” an underlying condition of spondyloarthritis, an arthritis that attacks the spine and is associated with lower back pain. That’s according to Israeli researchers writing in Arthritis Care & Research.

“Physicians involved in the management of FMS (fibromyalgia) should remain vigilant to the possibility of underlying inflammatory disorders and actively search for such comorbidities,” write Jacob Ablin, of Tel Aviv Sourasky Medical Center, and colleagues.

[Learn more about fibromyalgia symptoms.]

The researchers interviewed fibromyalgia patients and asked them about indicators of spondyloarthritis. They also conducted tests and ran magnetic resonance imaging (MRI) exams on the 99 patients, among whom they found 8 (representing 8.1 percent) with inflammation called sacroiliitis, which suggests spondyloarthritis, while 10 patients (10.2 percent) met spondyloarthritis diagnoses.

“These findings suggest that FMS (fibromyalgia) may mask an underlying axial SpA (spondyloarthritis), a diagnosis with important therapeutic implications,” the authors conclude.

[Learn about our Ankylosing Spondylitis Patient Guidelines]

“Current guidelines suggest that once a diagnosis of fibromyalgia syndrome is made, aggressive investigations should be avoided to minimize further discomfort or complication,” adds Rheumatology Network. “This suggestion confounds the discovery of underlying or concurrent inflammatory disease and may lead to underdiagnosis.”