Misdiagnosis of fibromyalgia and small-fibre polyneuropathy

Some people diagnosed with fibromyalgia may actually have small-fibre polyneuropathy (SFPN), says a new study.

People with fibromyalgia experience chronic widespread pain but specific abnormalities or causes have not been identified. SFPN has similar symptoms to fibromyalgia but is caused by the dysfunction and degeneration of peripheral small-fibre neurons. Its causes are established and some are treatable.

A small study published in Pain has shown that some people with chronic pain labelled as fibromyalgia actually have unrecognised SFPN, a distinct disease that can be tested for objectively and sometimes treated definitively.

“Until now, there has been no good idea about what causes fibromyalgia, but now we have evidence for some but not all patients,” says Dr AL Oaklander who co-authored the study. “Fibromyalgia is too complex for a ‘one size fits all’ explanation.”