This page has moved. Click here to view.


Chronic Fatigue Syndrome

Fatigue is a common complaint in the general population. Up to one quarter of patients seeking care from their primary care physician acknowledge fatigue as a major problem chronic fatigue syndrome, cronic fatigue syndrome, fatige. Fatigue is a common symptom of many acute infectious illnesses, and postinfectious fatigue may persist for weeks after resolution of other acute manifestations of the illness. Persistent fatigue can be a prominent, nonspe-cific manifestation of chronic conditions or illnesses, including endocrine (eg, hypothyroidism), connective tissue (eg, giant cell arteritis, polymyalgia rheumatica), neoplastic (eg, lymphoma), metabolic (eg, renal or hepatic insufficiency, morbid obesity), hematologic (eg, anemia, preleukemia), psychiatric (eg, depression), neurologic (eg, myasthenia gravis, multiple sclerosis), or chronic infectious (eg, osteomyelitis, endocarditis, toxoplasmosis) disorders. In addition, self-limited exhaustion can occur with unusual physical or emotional stress, generally resolving as the triggering disturbance clears chronic fatigue syndrome, cronic fatigue syndrome, fatige.

Chronic fatigue syndrome designates an illness of unknown etiology characterized by debilitating fatigue or exhaustion, often of sudden onset, lasting at least 6 months and resulting in substantial (>50%) reduction in premorbid activity and productivity levels. It is often associated with additional symptoms, including

Physician-based surveillance by the Centers for Disease Control and Prevention in four U.S. urban/suburban sites over a 4-year period demonstrated an overall prevalence of 6.4 cases per 100,000 persons, with rates between 4.0 and 8.7 per 100,000 in the four areas studied. Of patients referred with unexplained, debilitating fatigue or chronic unwellness for at least 6 months, only 23% met Centers for Disease Control and Prevention criteria; most patients


The cause of chronic fatigue syndrome remains unknown. Because onset of chronic fatigue syndrome often occurs with an apparent viral illness, commonly resembling infectious mononucleosis or an influenza-like illness, infectious agents have been studied widely, including Brucella species, enteroviruses, herpes viruses (including Epstein-Barr virus, cytomegalovirus, human herpes virus 6, herpes simplex viruses 1 and 2) and retroviruses (human T-cell lymphoma virus 2). None of these have been implicated convincingly either via primary infection or

Psychologic factors have been considered as a cause of chronic fatigue syndrome. Although 50% of patients with chronic fatigue syndrome satisfy criteria of major depression, this does not indicate that psychiatric illness is the explanation for chronic fatigue syndrome because chronic fatigue syndrome and depression share symptoms (fatigue, sleep disturbance, cognitive dysfunction). Depression can result from any chronic, debilitating illness. However, it is possible that premorbid (ie, pre-chronic fatigue syndrome) psychopathology may promote the development of chronic fatigue syndrome or amplify its

An immunologic cause has been proposed because some studies of immune responses and activation have demonstrated subtle abnormalities in lymphocyte response to mitogens, enhanced activity of proinflammatory cytokines, impaired natural killer cell cytotoxicity, and alteration in proportions of T-lymphocyte subsets. Some investigators have suggested that chronic fatigue syndrome results when a precipitating factor, especially an infectious disease, triggers lymphocyte and cytokine activation. However, the clinical and etiologic significance of these findings is unknown, other than to lend some 

Other proposed etiologies or factors in patients with chronic fatigue syndrome have included neurally mediated hypotension, primary sleep disorders, and 

Diagnostic Criteria

In 1988, the Centers for Disease Control and Prevention proposed a working case definition of chronic fatigue syndrome. In part because of inconsistent adherence to this definition, modifications have been proposed, most recently under the auspices of

To exclude conditions known to result in persistent fatigue and debility, initial evaluation of the patient should include a complete history (including inquiry into psycho-social conditions present at the onset of fatigue, such as depression and alcohol or other substance abuse) and physical examination. The physical examination in patients with chronic fatigue syndrome usually reveals no obvious abnormalities, although subtle findings, such as mildly enlarged or tender lymph nodes (cervical axillary, inguinal), mild pharyngitis (nonexudative but often with erythema-tous palatal arcs),

Centers for Disease Control and Prevention Case Definition of Chronic Fatigue


A. Major criteria

1. Persistent or relapsing fatigue for 6 months

(>50% reduction in activity)

2. Exclusion of other causative conditions

B. Minor criteria


1. Mild fever (37.5-38.6EC) orchills

2. Sore throat

3. Painful cervical or axillary lymph nodes

4. Generalized muscle weakness

5. Myalgia/muscle discomfort

6. Fatigue postexercise

7. Headaches (generalized)

8. Arthralgias (migratory)

9.Neuropsychiatric (cognitive dysfunction, irritability, depression, photophobia, scotomata)

10.Sleep disturbance

11.History that fatigue and associated symptoms developed abruptly

Physical Findings

1. Fever (37.6-38.6EC)

2. Pharyngitis (nonexudative)

3. Palpable/tender lymph nodes (cervical, axillary)

*Chronic fatigue syndrome is diagnosed if patient fulfills both major criteria and (a) at least eight symptom criteria or (b) at least six symptom criteria plus at least two physical criteria.


No specific therapies exist for chronic fatigue syndrome. Treatment is symptomatic, supportive, and psychosocial. Sleep disturbances often respond to treatment with benzodiazepines or Zolpidem for initiation of sleep and reduction of prolonged sleep latency. Tricyclic antidepressants, especially amitriptyline, taken at low doses 2 hours or less before bedtime, are useful for reduction in early awakening. Amitriptyline at low doses may prove helpful in initiating sleep and may improve myalgias as well. Long-acting nonsteroidal antiinflammatory agents may be more effective in treating myalgias and arthralgias, especially with use of a prebedtime dose for nocturnal muscle discomfort, which

Patients with obvious psychologic dysfunction, either primary or secondary, should be referred to a psychiatrist or psychologist for evaluation and therapy. Selective sero-tonin reuptake inhibitors such as fluoxetine and sertraline,

Cognitive and behavioral interventions should address the following:

Attitudes, providing education to promote supportive assistance from family members and 

Alternative and complimentary interventions may be helpful, including stress reduction therapies, light massage, and meditation. Herbal and vitamin therapies often are tried by chronic fatigue syndrome patients, but as yet the

The natural history of chronic fatigue syndrome is unknown, and the course of illness is unpredictable in the individual patient. About 20% of patients improve, seemingly completely, and may be said to have recovered, although many of these patients relapse if therapeutic behavioral changes revert to an overcommitted lifestyle. With careful management, most patients experience mild to moderate improvement, with periodic exacerbations triggered by