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The Great Masquerader

Apr 05, 2017 5:37 pm

Historically, syphilis and tuberculosis were the “great masqueraders” in medicine. They were labeled as such because of their protean symptoms, their myriad of presentations to any variety of clinician specialists and their historic long delays in diagnosis.

Multi-system disorders with varied presentations are ripe for perplexed views, expansive testing and inevitably, delays in diagnosis and treatment. In the modern era, a whole new generation of masqueraders, equally serious, have been anointed and labeled as great masqueraders. These include lupus, sarcoidosis, vasculitis (e.g., GPA) and lymphoma. Even though these grave diagnoses are quite uncommon, their presentations, symptoms, and criteria are well chronicled. 

Rheumatology is unique in that most non-rheumatologists don’t get it, don’t care about it or view it as voodoo medicine with acronym tests that often require decoder rings. These masqueraders are less of a challenge to those in the know.

But a far more common, ubiquitous masquerader has become the menace of diagnostic acumen in clinics, emergency departments and hospitals nationwide. Fibromyalgia eclipses all other masqueraders by being one of the most common cause of musculoskeletal complaints and a frequent cause of medical presentation.

Fibromyalgia is a pain amplification disorder driven by sleep disturbance, exaggerated pain, lowered pain thresholds (with magnified pain), and a dizzying multiplicity of symptoms = yet a paucity of abnormalities on clinical examination or laboratory testing.  

Fibromyalgia, affects nearly 4 million Americans, and over 7 million have “chronic widespread pain”. A survey I did several years ago showed that the majority of rheumatologists saw 5-10 FM patients per week. Even though FM outnumbers rheumatoid arthritis (RA), the same Rheums said they average about 22 RA patients per week.

Several years ago, Kavanaugh wrote a short article describing FM as “multiorgan dysesthesia”. He based this on the well-known associations between FM and other painful, spastic disorders and recognized that FM, presenting to another clinic or discipline, may be called something different (Table).  It’s the same disorder or related disorders seeking medical help for a central sensitivity syndrome.




TMJ syndrome


Migraine, neuropathy, cognitive dysfuntion


Interstitial cystitis, spastic bladder


Irritable bowel syndrome


Dysmenorrhea, vulvodynia, chronic pelvic pain


Cervical strain, disc disease


Allergic rhinitis, chronic sinusitis, multiple chemical sensitivities


Depression, Somatization disorder













 The masquerade and misdiagnosis is highly prevalent in both primary and specialty care, including rheumatology.  Why is this so often missed? Partly because FM seldom presents with a chief complaint of chronic widespread pain focused upon tender points with a sleep problem. Instead it presents in tricky, unfocused or multiple symptoms whose priority is determined by those affected.  

My last 3 new FM diagnoses presented as “uncontrolled gout”, “possible lupus with a positive ANA 1:80” and “right side pains”.  Of course, each of these had other tell-tale clues, but drawing these out requires a methodical approach and knowing that when the symptoms don’t fix the diagnosis its more prudent to consider a more common diagnosis (FM) than to try to fit a rare square peg in an unlikely round hole.

A FM diagnosis can be more easily identified by asking all patients about fatigue, sleep habits and patterns and recognizing co-associations like irritable bowel syndrome, dysmenorrhea, migraine, depression, anxiety, memory loss, non-anatomic paresthesia or dysesthesia, fatigue, TMJ pain, etc.

FM patients often see multiple specialists, are twice as likely to be hospitalized, and are often plagued by polypharmacy. Hence, they are often referred to multiple consultants and are subjected to multiple investigations and even surgical interventions. 

This very common masquerader mandates frequent consideration so as to avert needless investigation, ineffective therapy and prolonged duress for the patient.


The author has no conflicts of interest to disclose related to this subject
Dr. Cush is the Executive Editor of and also Co-Edits the online textbook 
Dr. Cush is a Professor of Internal Medicine at The University of Texas Southwestern Medical School, in the Rheumatic Diseases Division in Dallas, Texas. 
Dr. Cush's interests include medical education, novel drug development, rheumatoid arthritis, spondyloarthritis, drug safety, and Still's disease/autoinflammatory syndromes. He has published over 140 articles and 2 books in rheumatology.
He can be followed on twitter: @RheumNow

Rheumatologists’ Comments

David S Knapp

| Apr 05, 2017 7:54 pm

I agree totally. The cause of fibromyalgia is life's challenges and the person's resources to recognize, respond appropriately and address the issues constructively. I have never seen a fibromyalgia patient who was "living happily ever after". Nevertheless, as rheumatologists were are committed to helping our medical colleagues who do not like the clinical uncertainty and the patients who have a terrible quality of life. We can protect the patients from iatrogenesis and provide a meaningful explanation so they can go about seeking assistance with their life's circumstances. A little cognitive therapy goes a long way. Caveat: some patients are so disappointed or concrete (defense mechanisms, mood disturbances, abuse issues, personalty disorder, intellectual deficits) they may try to "kill the messenger" when they don't like the message. No doubt many patients with entrenched illness and pain behavior with associated "drama" require a lot of time and can drain the resources of the entire staff. Also, fibromyalgia can confound and hinder the determination of co-existing medical pathology. We have to help the patient help themselves with support, reassurance and information. Not easy!

Robert Kimelheim

| Apr 13, 2017 9:17 pm

I have taken to administering a HAQ to a majority of my patients and have found a curious disconnect ( FMS patients ) between the level of pain and the generally low HAQ scores - observed phenomenon.

Robert Kimelheim

| Apr 13, 2017 9:17 pm

Another great masquerader - Atrial Myxoma...

John A. Goldman, MD

| May 04, 2017 9:07 pm

Good Narrative. The trifecta for fibromyalgia is poor sleep, poor exercise and poor control of stress and other psychological issues. They can have one, two or all three. I encourage therapy directed to all three. There is no major answer as each person is different. They often don't get respect and as David notes can confound many different medical problems. Some Colleagues won't make the diagnosis thus sparing the discussion. Often reviewing the multiple answers on the history form can quickly be a clue. My staff can make the diagnosis on the entry telephone call. Don't be fooled and always look for some of the associated illnesses which also can co-exist.

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