A recent study published in the journal Pain sheds some light on the ongoing debate about the causal relationship between neck injuries sustained during a car accident and the development of the pain condition fibromyalgia. Chiropractors commonly treat patients with both conditions, and separating these diagnoses can improve treatment. The latest research suggests that fibromyalgia may be overdiagnosed in patients who have a history of whiplash injury due to a motor vehicle accident.
People with fibromyalgia experience a range of life-disrupting symptoms, include general and localized pain, fatigue, and difficulty sleeping. Neck and shoulder tenderness is one common indicator that practitioners use to diagnose fibromyalgia; general pain lasting longer than three months is another. However, these symptoms also are common among patients experiencing the lingering effects of whiplash. Some past research has shown that people with neck injuries incurred in a motor vehicle accident are 13 times more likely to develop fibromyalgia than those with other injuries. Other studies have questioned these conclusions.
Researchers at the University of Washington set out to investigate the prevalence of fibromyalgia in whiplash patients with persistent neck pain. They questioned whether the most common set of criteria used for diagnosing fibromyalgia may rely too heavily on evaluating trigger points located in the neck and shoulder. The study participants included 326 individuals with whiplash-associated neck pain that had lasted longer than 3 months. The participants were enrolled in a 6-week treatment program for their symptoms that consisted of educational therapy sessions.
The researchers evaluated the patients for fibromyalgia both at the beginning and the end of the program. Two sets of criteria were used to diagnose fibromyalgia: the standard guidelines and adjusted guidelines that discounted the importance of pain in the neck and shoulder area. Using the standard guidelines, the researchers initially diagnosed 14% of the whiplash participants with fibromyalgia. This rate dropped to 8% using the adjusted guidelines.
These findings suggest that health practitioners who treat patients with persistent neck pain, such as chiropractors, may be led to significantly overdiagnose fibromyalgia in their patients. People with a history of whiplash-associated injuries should be aware of this unintended bias, and report their injury history.

Robinson JP, Theodore BR, Wilson HD, Waldo PG, Turk DC. Determination of fibromyalgia syndrome after whiplash injuries: Methodologic issues. Pain. 2011 Mar 16.