Fibromyalgia is a complex chronic widespread pain disorder estimated to affect 2-8% of the population. It is characterized by core symptoms of musculoskeletal pain, fatigue, sleep disturbances, cognitive dysfunction and mood disorders.
Due to its variable presentation and lack of definitive diagnostic tests, fibromyalgia is often misdiagnosed, leading to delays in appropriate treatment.
Reasons Fibromyalgia is Commonly Misdiagnosed
Several factors contribute to the high rate of misdiagnosis of fibromyalgia:
- There are no laboratory or imaging tests that can conclusively diagnose fibromyalgia.
- Symptoms like pain, fatigue, insomnia, depression overlap with many other conditions.
- Some healthcare providers have lower awareness of fibromyalgia diagnostic criteria.
- Referral to rheumatology for specialty assessment is sometimes delayed.
Common Conditions Mistaken for Fibromyalgia
Fibromyalgia is often confused with the following conditions exhibiting similar symptoms:
- Chronic fatigue syndrome – characterized by extreme, persistent fatigue.
- Rheumatoid arthritis – an autoimmune condition causing joint inflammation.
- Lupus – a systemic autoimmune disease that can produce pain and fatigue.
- Polymyalgia rheumatica – inflammatory disorder causing muscle stiffness and achiness.
- Depression/anxiety – mood disorders frequently associated with fibromyalgia.
What does medical studies say about misdiagnosis of fibromyalgia?
Fibromyalgia is frequently misdiagnosed, both overdiagnosed and underdiagnosed, according to several studies. Franco et al. (2011) found that 13% of fibromyalgia patients had previously been misdiagnosed with other conditions[1]Dizner-Golab A, Lisowska B, Kosson D. Fibromyalgia–etiology, diagnosis and treatment including perioperative management in patients with fibromyalgia. Reumatologia. 2023;61(2):137.. Häuser et al. (2019) note that fibromyalgia can be challenging to diagnose accurately due to its overlap with other disorders[2]Häuser W, Sarzi-Puttini P, Fitzcharles MA. Fibromyalgia syndrome: under-, over-and misdiagnosis. Clin Exp Rheumatol. 2019 Jan 1;37(Suppl 116):90-7..
Fitzcharles et al. (2003) found a “disturbing inaccuracy” in fibromyalgia diagnosis, with overdiagnosis being the most common error[3]Fitzcharles MA, Boulos P. Inaccuracy in the diagnosis of fibromyalgia syndrome: analysis of referrals. Rheumatology. 2003 Feb 1;42(2):263-7.. Some reasons for misdiagnosis include a lack of understanding of fibromyalgia among physicians (Arnold 2011), as well as the fact that fibromyalgia often co-occurs with other conditions, complicating diagnosis (Fitzcharles 2018). For example, fibromyalgia frequently accompanies inflammatory arthritis and other rheumatological disorders (Franco 2011; Fitzcharles 2018).
It is also associated with a variety of other conditions like gastrointestinal disorders, mental health conditions, and other chronic pain disorders (Fitzcharles 2018). When physicians fail to recognize fibromyalgia in these cases, they may incorrectly attribute symptoms to the co-occurring condition (Fitzcharles 2018).
On the other hand, fibromyalgia is also frequently underdiagnosed, according to several studies. Forseth et al. (1992) found that although 85% of women with fibromyalgia had seen a doctor for symptoms, only 41% had received an actual diagnosis of fibromyalgia. Cohen (2017) argues that fibromyalgia remains poorly understood by many physicians, leading them to miss the diagnosis.
Wolfe (1994) notes that some patients who appear to have fibromyalgia will not meet classification criteria, and thus may go undiagnosed. In summary, while fibromyalgia is a well-known disorder, challenges in diagnosis and a lack of understanding have led to disturbingly high rates of misdiagnosis, especially overdiagnosis but also underdiagnosis (Fitzcharles et al. 2003).
Improved education about fibromyalgia for physicians and a multidisciplinary, biopsychosocial approach to diagnosis may help address this issue (Arnold 2011; Cohen 2017; Häuser 2019).
Overlapping Conditions: The Challenge of Diagnosis
Complicating matters further, fibromyalgia can overlap with other conditions, including autoimmune diseases like lupus or rheumatoid arthritis.
Patients may experience what’s known as “secondary fibromyalgia,” where pain occurs in both muscles and joints. It’s hoped that by addressing the primary condition (like lupus), the fibromyalgia symptoms might alleviate. However, this isn’t always the case.
The Underlying Cause: Brain Chemistry Imbalance
Recent research suggests that fibromyalgia stems from an imbalance of certain chemicals in the brain, notably serotonin, norepinephrine, and substance P. These chemicals modulate pain perception.
A deficit in serotonin and norepinephrine results in an increased pain experience, while an abundance of substance P, which is associated with pain, can exacerbate the condition.
One intriguing aspect is that the pain doesn’t always originate from the area where it’s felt. For instance, women with fibromyalgia might experience pelvic pain that persists even after medical interventions like a hysterectomy. This is because the pain originates in the brain, not the pelvis.
Impacts of Misdiagnosis
The impacts of misdiagnosing fibromyalgia include:
- Delay in initiating appropriate fibromyalgia treatment.
- Potentially unnecessary diagnostic testing and medication trials.
- Increased healthcare costs due to extended diagnostic odyssey.
- Progression of undiagnosed co-existing conditions like autoimmune disorders.
Improving Diagnostic Accuracy
To reduce misdiagnosis rates and improve timely diagnosis of fibromyalgia, providers should focus on:
- Thorough clinical history detailing the quality, timing, location of pain.
- Physical exam assessing presence of tender points.
- Lab testing and imaging to rule out other potential causes.
- Increased education on fibromyalgia diagnostic criteria and features.
- Prompt referral to rheumatology when fibromyalgia is suspected.
Patients must also advocate for their health by clearly describing their symptoms, requesting specialty referrals, and seeking second opinions when there is uncertainty.
Physiatrist, M.D. Pain Center of University of São Paulo
References
| ↑1 | Dizner-Golab A, Lisowska B, Kosson D. Fibromyalgia–etiology, diagnosis and treatment including perioperative management in patients with fibromyalgia. Reumatologia. 2023;61(2):137. |
|---|---|
| ↑2 | Häuser W, Sarzi-Puttini P, Fitzcharles MA. Fibromyalgia syndrome: under-, over-and misdiagnosis. Clin Exp Rheumatol. 2019 Jan 1;37(Suppl 116):90-7. |
| ↑3 | Fitzcharles MA, Boulos P. Inaccuracy in the diagnosis of fibromyalgia syndrome: analysis of referrals. Rheumatology. 2003 Feb 1;42(2):263-7. |