Fibromyalgia (FM): Diagnostic Criteria

[Pyrrhus]

Fibromyalgia: Diagnostic Criteria​

In 1995, as an undergraduate, I was asked to put together a brief review of the literature on fibromyalgia. At the time, I knew little about fibromyalgia and absolutely nothing about ME/cfs. In my brief review, which I recently unearthed, I noted that there seemed to be multiple conceptions of fibromyalgia as well as a strange emphasis on psychological factors. Now, 25 years later, I have decided to take another look to see how our understanding of fibromyalgia has evolved.

This discussion is intended to take a historical look at the different diagnostic criteria that have been used to define fibromyalgia (FM), beginning with the current diagnostic criteria:

AAPT Diagnostic Criteria for Fibromyalgia (Arnold et al., 2018)
https://doi.org/10.1016/j.jpain.2018.10.008

The current diagnostic criteria for fibromyalgia was defined in 2018 by an international working group consisting of clinicians and researchers with expertise in fibromyalgia. The working group was assembled by the American Pain Society (APS) and the U.S. Food and Drug Administration (FDA). It is the first set of diagnostic criteria put together by pain specialists, rather than by rheumatologists.

The [ACTTION-APS Pain Taxonomy (AAPT)] established an international [fibromyalgia (FM)] working group consisting of clinicians and researchers with expertise in FM to generate core diagnostic criteria for FM. [...] The process for developing the AAPT criteria and dimensions included literature reviews and synthesis, consensus discussions, and analyses of data from large population-based studies conducted in the United Kingdom. [...] Future studies will assess the criteria for feasibility, reliability, and validity.

So far, so good.

The multiple symptoms and comorbidities associated with FM make it difficult to diagnose, and FM is still underdiagnosed and undertreated. The diagnosis of FM might take >2 years, with patients seeing an average of 3.7 different physicians during that time.

Sounds familiar.

The Fibromyalgia Working Group proposed a reduction in non-pain symptoms for inclusion [...] as core diagnostic criteria to reduce the complexity of diagnosis and make the FM criteria easier to use in practice. The Fibromyalgia Working Group identified fatigue and sleep problems as 2 key associated symptoms for several reasons. First, these symptoms, along with chronic pain, occur in most patients with FM. [...] Finally, responder definitions using fatigue and sleep problems, in combination with pain and physical function, were shown to be responsive to change in FM clinical trials.

So, in addition to "multi-site pain", both fatigue and sleep problems are now considered core diagnostic criteria for fibromyalgia. But what exactly do they mean by "fatigue"?

Fatigue is defined as physical or mental fatigue judged as at least moderate severity by the health care professional. Physical fatigue may manifest as a complaint of physical exhaustion after physical activity, including an inability to function within normal limits for activities that constitute normal daily activities and the requirement for rest periods after activity.

An "inability to function within normal limits for activities that constitute normal daily activities" - now this sounds familiar. A "requirement for rest periods after activity" - now this sounds even more familiar.

And what exactly do they mean by "sleep problems"?

Sleep problems are defined as difficulty falling or staying asleep, frequent awakening that is disturbing during a sleep period, or feeling unrefreshed after sleep.

So basically, insomnia and unrefreshing sleep.

They also clarify that a diagnosis of fibromyalgia does NOT exclude other, overlapping diagnoses:

The presence of other disorders does not necessarily exclude a diagnosis of FM, and all disorders will need clinical attention.

In addition to the core diagnostic criteria, they also list supporting diagnostic criteria.

Features that are not included in [core diagnostic criteria] but may be used to support a diagnosis of FM are described below. [...] Dyscognition (eg, trouble concentrating, forgetfulness, and disorganized or slow thinking) is increasingly recognized as a major feature of FM, with dysfunction being seen in working memory and executive function. [...] Environmental sensitivity or hypervigilance, manifesting as intolerance to bright lights, loud noises, perfumes and cold, is a common complaint of FM patients.

So, cognitive dysfunction (brain fog) is a "major feature" of fibromyalgia and hypersensitivities to light, sound, odors, etc. are "common complaints".

They then explicitly acknowledge the similarity to ME/cfs.

Chronic fatigue syndrome is a condition that has considerable overlap with FM, with the predominance of pain an identifier of FM.

But then they engage in the usual speculation about the role of psychological factors and comorbidities.

FM, especially the “primary” form, is also very comorbid with early life and current stress, and many, if not most, individuals will have a lifetime history of a psychiatric disorder such as depression or anxiety.

Finally, they acknowledge that their diagnostic criteria are not perfect, and that pain might not even be the most disabling symptom in fibromyalgia.

The challenge shared by all attempts to define criteria for FM is that there is no gold standard for FM diagnosis. [...] The AAPT taxonomy offers a new approach by defining core criteria and including other associated symptoms and signs, comorbidities, and impact on function in other dimensions. [...] Although pain is the main symptom of FM, other symptoms are reported to be clinically significant by patients and are sometimes more disabling than pain.

The actual diagnostic criteria are detailed in the following post.

 

[Pyrrhus]

AAPT Diagnostic Criteria for Fibromyalgia (Arnold et al., 2018)
https://doi.org/10.1016/j.jpain.2018.10.008

The current diagnostic criteria for fibromyalgia was defined in 2018 by an international working group consisting of clinicians and researchers with expertise in fibromyalgia. The process for developing the diagnostic criteria included literature reviews and synthesis, consensus discussions, and analyses of data from large population-based studies. It is the first set of diagnostic criteria put together by pain specialists, rather than by rheumatologists.


In summary, these are the current diagnostic criteria for fibromyalgia:

Core Diagnostic Criteria: ("dimension 1")

1. Multi-site pain (MSP) defined as 6 or more pain sites from a total of 9 possible sites (see diagram below)​

2. Moderate to severe sleep problems OR fatigue​

3. MSP plus fatigue or sleep problems must have been present for at least 3 months​

Supporting Signs and Symptoms: ("dimension 2")

1. Tenderness (muscle soreness)​

2. Cognitive dysfunction (formerly known as "brain fog")​

3. Musculoskeletal stiffness​

4. Sensory hypersensitivity or hypervigilance (hypersensitivities to light, sound, odors, etc.)​

Comorbidities ("dimension 3")

1. ME/CFS​

2. Irritable Bowel Syndrome (IBS)​

3. chronic pelvic pain or interstitial cystitis​

4. chronic head or orofacial conditions such as temporomandibular disorder, otologic symptoms​

5. chronic headaches, or migraine disorder​

6. sleep disorders​

7. joint hypermobility​

8. rhinitis and urticaria​

9. rheumatic conditions​

10. obesity​

11. anxiety disorders​

12. major mood disorder​

13. substance abuse disorder​

​

​

Multi-site pain:

"Multi-site pain" is defined as pain in six or more of the following nine un-shaded parts of the body:​

Fatigue:

Fatigue is defined as physical or mental fatigue judged as at least moderate severity by the health care professional. Physical fatigue may manifest as a complaint of physical exhaustion after physical activity, including an inability to function within normal limits for activities that constitute normal daily activities and the requirement for rest periods after activity.​

​

Sleep problems:

Sleep problems are defined as difficulty falling or staying asleep, frequent awakening that is disturbing during a sleep period, or feeling unrefreshed after sleep.​

 

[Pyrrhus]

A bit of history​

Back in the 1970s, fibromyalgia was generally called "fibrositis" and was considered a poorly-defined rheumatological disorder.

In the 1980s, different rheumatologists began different efforts to standardize the diagnostic criteria for fibromyalgia. Some people, like Muhammad Yunus, wanted to include all the symptoms that patients had. Other people, like Fred Wolfe, just wanted to focus on the single symptom of pain.

Muhammad Yunus had a theory. He wanted to encompass a range of poorly defined illnesses such as fibromyalgia, IBS, ME/CFS, and many others into a single diagnosis. (which would eventually come to be known as "Central Sensitivity Syndrome") He felt that all these diseases were really one disease caused by a neurological hypersensitivity in the brain.

Fred Wolfe was skeptical of this idea. He thought that the more symptoms a patient had, the more likely it was that they were simply imagining their symptoms due to an underlying psychiatric disorder.

So in 1986, Yunus, Wolfe, and other rheumatologists got together to try to agree on a consensus set of diagnostic criteria for fibromyalgia. The result of this effort was the 1990 set of diagnostic criteria from the American College of Rheumatology.

 

[Pyrrhus]

The american college of rheumatology 1990 criteria for the classification of fibromyalgia (Wolfe et al., 1990)
https://doi.org/10.1002/art.1780330203

To develop criteria for the classification of fibromyalgia, we studied 558 consecutive patients: 293 patients with fibromyalgia and 265 control patients.
[...]
The newly proposed criteria for the classification of fibromyalgia are
1) widespread pain in combination with
2) tenderness at 11 or more of the 18 specific tender point sites.
No exclusions are made for the presence of concomitant radiographic or laboratory abnormalities.
[...]
In 1986, a consortium of centers interested in the fibromyalgia syndrome began a study of criteria for the diagnosis of primary and secondary-concomitant fibromyalgia. [...] The committee’s 4 specific objectives were
1) to provide a consensus definition of fibromyalgia;
2) to establish new criteria for the classification of fibromyalgia;
3) to study the relationship of “primary” fibromyalgia to “secondary” or “concomitant” fibromyalgia in terms of classification criteria; and
4) to ascertain how well previous criteria sets worked in a multicenter data set and to establish their relationship to the new criteria.
[...]
The consensus of the committee was to adopt the term fibromyalgia, which was first suggested by Hench in 1976, rather than the older term fibrositis. [...] In this report, we propose criteria for fibromyalgia that may apply equally well to both primary and secondary syndromes.

 

[Pyrrhus]

Twenty years later, Muhammad Yunus, Fred Wolfe, and others tried to clarify the 1990 diagnostic criteria. This 2010 update includes a new author who had not been involved in the 1990 criteria: Daniel Clauw.


The American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia and Measurement of Symptom Severity (Wolfe et al., 2010)
https://www.rheumatology.org/Portals/0/Files/2010_Preliminary_Diagnostic_Criteria.pdf

Objective.
To develop simple, practical criteria for clinical diagnosis of fibromyalgia that are suitable for use in primary and specialty care and that do not require a tender point examination, and to provide a severity scale for characteristic fibromyalgia symptoms.
[...]
Methods.
We performed a multi-center study of 829 previously diagnosed fibromyalgia patients and controls using physician physical and interview examinations.
[...]
Results.
Approximately 25% of fibromyalgia patients did not satisfy the American College of Rheumatology (ACR) 1990 classification criteria at the time of the study.
[...]
Conclusion.
This simple clinical case definition of fibromyalgia correctly classifies 88.1% of cases classified by the ACR classification criteria, and does not require a physical or tender point examination.

Introduction.
The introduction of the American College of Rheumatology (ACR) fibromyalgia classification criteria 20 years ago began an era of increased recognition of the syndrome. The criteria required tenderness on pressure (tender points) in at least 11 of 18 specified sites and the presence of widespread pain for diagnosis.
[...]
Over time, a series of objections to the ACR classification criteria developed, some practical and some philosophical. First, it became increasingly clear that the tender point count was rarely performed in primary care.
[...]
Second, the importance of symptoms that had not been considered by the ACR Multicenter Criteria Committee became increasingly known and appreciated as key fibromyalgia features: for example, fatigue, cognitive symptoms, and the extent of somatic symptoms.
[...]
These criteria are not meant to replace the ACR classification criteria, but to represent an alternative method of diagnosis.

 

[Pyrrhus]

Six years after the 2010 update to the diagnostic criteria, there was another revision. This time, Muhammad Yunus was not involved. Instead, a new author was included who had not been involved in previous diagnostic criteria: Brian Walitt.


2016 Revisions to the 2010/2011 Fibromyalgia Diagnostic Criteria (Wolfe et al., 2016)
https://acrabstracts.org/abstract/2016-revisions-to-the-20102011-fibromyalgia-diagnostic-criteria/

In this 2016 fibromyalgia criteria update, we address identify problems and provide further guidelines for use.
[...]
The revision makes the following changes:
[...]
4) Removes the exclusion regarding disorders that could (sufficiently) explain the pain (criterion 4) and adds the following text: 'A diagnosis of fibromyalgia is valid irrespective of other diagnoses. A diagnosis of fibromyalgia does not exclude the presence of other clinically important illnesses.'

 

[Pyrrhus]

The collapse of consensus among rheumatologists​

In 2016, the group of rheumatologists who were historically involved in the diagnostic criteria for fibromyalgia collapsed due to internal divisions.

Muhammad Yunus went his own way, still pushing his old theory of a "Central Sensitivity Syndrome".

Meanwhile, Fred Wolfe threw his hands up and declared that all the efforts to define fibromyalgia had failed.

In a sharply-worded editorial, Fred Wolfe and Brian Walitt declared that fibromyalgia was not a real disease:

Fibromyalgia: A Short Commentary (Wolfe and Walitt, 2016)
https://www.researchgate.net/publication/310835395_Fibromyalgia_A_Short_Commentary

75% of Persons in the General Population Diagnosed with Fibromyalgia Don’t Have It, But It Is Worse Than That…
[...]
Whether fibromyalgia is determined by the tender point examination of the 1990 fibromyalgia criteria or by the symptom assessment tools of the 2010/2011 criteria, fibromyalgia assessments are always subjective; they are influenced by biologic, psychosocial and environmental factors and, in clinical settings, by the beliefs and biases of physicians and patients.

A [diagnosis] of fibromyalgia can legitimize vague and difficult or distressing symptoms, allowing entrée into official diagnosis and government approved treatments, or providing a way toward official disability status. All doctors and patients have to do is agree on the diagnosis. There is no reliable way to dispute such a diagnosis, and such a [diagnosis] can be 'helpful' to the patient and to the physician who struggles to handle a difficult problem and sometimes a difficult patient.
[...]
What these data mean, practically, is that psychosocial and environmental forces, physician and patient’s beliefs strongly affect fibromyalgia diagnosis and status. The distinguished medical historian Edward Shorter characterized fibromyalgia as a 'psychic epidemic, an illness attribution that spreads epidemically, and then is forgotten.'
[...]
Finally, there has been an enormous and often quite successful effort by patient support groups to legitimize fibromyalgia and support fibromyalgia physicians.

This collapse of consensus among rheumatologists allowed Daniel Clauw and other pain specialists to take over the definition of fibromyalgia, resulting in the current 2018 AAPT Diagnostic Criteria for Fibromyalgia.

 

[lenora]

Thanks @Pyrrhus......Good information especially since I was involved from the very beginning with FM and it's many painful symptoms.

I had often wondered when rheumatologists became such "experts" at diagnosing FM? So many approaches were tried over the years and, again, it's another complex disease that doesn't affect everyone the same way. Now it sounds as if we're back at square one. You're a good researcher yourself. Yours, Lenora.

 

[kangaSue]

Still no mention made in their consensus that a skin punch biopsy should also be done to rule out the co- involvement, or even the alternative diagnosis, of small fibre neuropathy.

 

[Pyrrhus]

Still no mention made in their consensus that a skin punch biopsy should also be done to rule out the co- involvement, or even the alternative diagnosis, of small fibre neuropathy.

The only mention in the 2018 diagnostic criteria is this sentence:

There is also a current ongoing controversy regarding the meaning of finding decreased intra-epidermal nerve fiber density (ie, small-fiber neuropathy) in FM.

So all the studies that found small fiber neuropathy (SFN) in fibromyalgia are still "controversial".

 

[Pyrrhus]

I had often wondered when rheumatologists became such "experts" at diagnosing FM? So many approaches were tried over the years and, again, it's another complex disease that doesn't affect everyone the same way. Now it sounds as if we're back at square one.

As it turns out, rheumatologists were never experts at diagnosing FM. They were only experts at predicting FM diagnoses from other doctors.

Instead of examining many patients, looking for patterns among the signs and symptoms, and then identifying coherent groups of patients that appear to have the same condition, rheumatologists took a completely different approach when coming up with their diagnostic criteria.

Instead, they looked at many patients who had already received a diagnosis of fibromyalgia by a doctor, and then tried to come up with diagnostic criteria that would include all these patients who had already received a diagnosis of fibromyalgia.

Basically, instead of trying to define fibromyalgia as a coherent condition, they tried to define fibromyalgia based on the pre-existing bias of doctors. An approach that was doomed to fail, and fail it did.

So yes, after 30 years of screw-ups by rheumatologists, we are back at square one. And that's a good thing.

 

[Rufous McKinney]

Great Post!

My medical records likely never even mention: oh yeah and everything hurts, too.

 

[PhoenixDown]

Fred Wolfe was skeptical of this idea. He thought that the more symptoms a patient had, the more likely it was that they were simply imagining their symptoms due to an underlying psychiatric disorder.

That is dangerous quackery as far as I'm concerned. I had my progressive ME misdiagnosed as Fibromyalgia and was treated horribly as a result. The main problem with a Fibromyalgia diagnosis is that your symptoms will be treated as if they are inconsequential. Peter White in this video:

agrees with your quote about "more symptoms a patient has..." = psychological but as is typical with psychologists, he provides absolutely no evidence for his claims and that really angers me. White also admits psychiatrists changed the definition of ME from 1955 Ramsey to fatigue.

I think CFS, Fibromyalgia, and IBS will turn out to be dozens of different illnesses that doctors can't figure out yet.

 

[Pyrrhus]

Related discussions:

Fibromyalgia or ME/CFS?
https://forums.phoenixrising.me/threads/fibromyalgia-or-me-cfs.29071/

Poll: Do You Have Fibromyalgia?
https://forums.phoenixrising.me/threads/do-you-have-fibromyalgia.13531/