Back to RHEUMATOLOGYFibromyalgia syndrome, also referred to as fibrositis, is an underdiagnosed disorder of unknown etiology affecting over 5% of the patients in general practice (Campbell 1983) and approximately 2-4% of the general population (Wolfe 1993). The term fibrositis is a misnomer, since this is not an inflammatory disorder of the connective tissue; therefore the term fibromyalgia is now preferred.
Fibromyalgia syndrome is a common cause of muscloskeletal symptoms both in its generalized and localized forms. It is characterized by chronic diffuse pain and, on examination, areas of focal tenderness called tender points which can be demonstrated in characteristic locations. It occurs predominantly (80 to 90%) in women of childbearing age (between the ages of 25 and 45 years).
A large number of other symptoms are often present, particularly fatigue, morning stiffness and sleep disturbance. These are the central symptoms of fibromyalgia and each is present in more than 75% of fibromyalgia patients (ACR 1990). The simultaneous presence of these three symptoms, however, is not required. Other conditions that occur in the context of fibromyalgia syndrome include ‘tension’ headaches, chronic anxiety, irritable bowel syndrome, fluid retention, paresthesias, Raynaud’s phenomenon, sicca symptoms, dysmenorrhea and prior depression. A history of these conditions will also make the likelihood of fibromyalgia syndrome more apparent. Clues to the possibility of fibromyalgia syndrome are detailed in (Table 1).
Fibromyalgia has mistakenly been thought to be either an inflammatory or a psychiatric condition. However, no evidence of inflammation or arthritis has been found. In addition, a number of studies have established that fibromyalgia syndrome is neither a psychosomatic nor somatiform disorder and that when present, depression and anxiety are more likely the result than the cause of fibromyalgia (Goldberg 1989, Yunus 1994).
There are many theories regarding the etiology of the fibromyalgia syndrome. It has been suggested that fibromyalgia syndrome may be due to non-restorative deep sleep (Moldofsky 1975,1993). Sleep studies in patients with fibromyalgia have shown abnormal amounts of alpha activity and less REM sleep, indicating disturbed and unrefreshed sleep; however, patients with chronic pain from other causes may have similar sleep patterns. Fibromyalgia-like symptoms were produced in normal volunteers by depriving them of deep sleep (by disturbing stage 4, non-REM, sleep with a buzzer without wakening them), except in those who exercised regularly (Moldofsky 1975). Exercise increases time spent in deep sleep, perhaps the mechanism for its therapeutic efficacy (Mc Cain 1988).
Muscle abnormalities also have been proposed to play a role in this disorder. It has been suggested that the pain of fibromyalgia syndrome is related to microtrauma in deconditioned muscles and that exercise works by conditioning these muscles (Bennett 1989). However, muscle biopsy has tended to show only changes of disuse atrophy and some tender points are not even over muscles or tendons, such as the one over the medial fat pad of the knee.
The diagnosis of fibromyalgia syndrome is made by recognizing its clinical manifestations. (See table 1 for clues to the possibility of fibromyalgia syndrome.) The characteristic physical feature is the demonstration of specific tender points which are exquisitely more tender than adjacent areas. Tender points should be distinguished from the trigger points found in miofascial pain syndromes. Pressure over trigger points causes pain to be referred to a nearby site, while pressure over tender point causes pain only at that site. The patient may suddenly jump, flinch or withdraw when the tender site is palpated. The sites of tenderness are remarkably constant in location and are better described in (Figure 1)
.The American College of Rheumatology established as criteria for the classification of fibromyalgia the presence of 11 of 18 tender points (defined as mild or greater tenderness) in addition to the presence of widespread pain (Table 2). For classification purposes, patients are said to have fibromyalgia if both criteria are satisfied. Widespread pain, defined as pain in the right and left side of the body and pain above and below the waist in addition to axial skeletal pain, must have been present for at least three months.
Although there have been many abnormalities of laboratory and other tests reported in fibromyalgia syndrome, none is sufficiently sensitive or specific to be useful diagnostically. Therefore, routine laboratory or other studies are not recommended. Because the list of symptoms is large in fibromyalgia syndrome, the differential diagnosis is also very large. Patients with fibromyalgia syndrome should have a comprehensive medical evaluation as part of the workup.
The diagnosis of fibromyalgia remains valid despite other diagnosis. In other words, the presence of a second clinical disorder does not exclude the diagnosis of fibromyalgia. “Exclusionary tests” such as radiographs, antinuclear antibody titers, T4 levels, etc. are not a requisite for diagnosis, therefore. However, it is evident that fibromyalgia often occurs in association with other rheumatic disorders, and it is incumbent upon the physician to seek out such problems, since the effective treatment of these conditions may influence the management of fibromyalgia. A distinction is no longer made between primary or secondary fibromyalgia (concomitant with other disease).
Since fibromyalgia syndrome is a syndromic diagnosis, any patient who fits the diagnostic criteria of aching all over and the presence of at least 11 of 18 tender points (Figure 1) has it by definition. It is not possible to accurately diagnose fibromyalgia syndrome without knowing how to do a tender point examination. It is not a diagnosis of exclusion. If the patient has typical symptoms of fibromyalgia syndrome but does not meet the tender point criterion, a diagnosis of “possible fibromyalgia” may be assigned and a therapeutic trial of standard treatment offered. Tender points should be looked for again on a return visit as they may be present some days and not others in some patients.
Careful clinical examination and appropriate selected investigations will eliminate most of the common problems that might mimic the condition. With accurate diagnosis comes appropriate explanation as to the nature of the syndrome and reassurance on the absence of other problems that may be worrying the patient such as arthritis, cancer or other poorly perceived conditions such as multiple sclerosis. Patients should be informed that they have a treatable condition which is not a crippling, deforming, or degenerative process.
Taking medication by itself has relatively little effect on fibromyalgia symptoms. Successful treatment requires active involvement of the patient in his or her care, including:
1) Medication to improve deep sleep.
The use of trycyclics such as amitriptyline, doxepin or cyclobenzaprine at bedtime will give the patient restorative sleep resulting in clinical improvement. Benzodiazepines other than alprazolam are contraindicated as they block stage 4 sleep and may exarcebate fibromyalgia symptoms.
2) Regular sleep hours and an adequate amount of sleep.
Getting adequate sleep is essential. Fibromyalgia symptoms often appear during times of sleep disruption such as may be brought on by an injury or other pain, stress, shift work, or having to get up to attend to young children. At times just re-establishing a regular sleep schedule may be enough to improve symptoms.
3) Daily gentle aerobic exercise.
Daily, gentle, low-impact aerobic exercise helps, but too much or the wrong kind of exercise may exarcebate fibromyalgia symptoms.
4) Avoidance of undue physical and emotional stress.
5) Treatment of any coexisting sleep disorders.
Other coexisting sleep disorders such as obstructive sleep apnea and periodic limb movements of sleep must be identified and treated
6) Patient education.
The patient with fibromyalgia syndrome is treated in the context of their total life, family and personal situation, and strategies to deal with fibromyalgia syndrome are based on the premise that the patient does not have to ‘learn to live with it’ but that the pain syndrome will usually improve significantly with this understanding approach.
1. Littlejohn G. Difficult Fibromyalgia. In:Klipple JH, Dieppe PA, eds. Pratical Rheumatology. London: Mosby; 1995:128-129
2. Gilliland BC. Relapsing Polychondritis and Miscellaneous Arthritides. In: Isselbacher K J, Braunwald E, Wilson JD, Martin JB, Fauci AS, Kasper DL, eds. Harrison’s Principles of Internal Medicine, 13E. United States of America, McGraw-Hill Inc; 1994:1706-7.
3. Ball EV. Nonarticular Rheumatism. In: Bennett JC, Plum F, eds. Cecil Textbook of Medicine, 20E. Philadelphia, WB Saunders; 1996:1527.
4. Wolfe F et al. The American College of Rheumatology 1990 Criteria for the classification of fibromyalgia: report of the multicenter criteria committee. Arthritis Rheum. 33:160, 1990.
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