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.
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.