Chronic fatigue syndrome.

The chronic fatigue syndrome (CFS) is a poorly understood condition with nonspecific signs and symptoms, especially debilitating fatigue. Most patients can pinpoint the onset of their illness and usually describe a flu-like state. The search for an etiologic agent has focused on a number of viruses such as Epstein-Barr, enteroviruses, retroviruses, and human herpesvirus-6. Evidence supports persistent viral infection in a small percentage of CFS patients. Immunologic abnormalities do exist in CFS, which indicate the presence of immune activation in CFS patients. Although abnormal muscle biopsies have been found in some patients with CFS, strength and endurance appear normal, but perception of exertion may be abnormal. Patients with chronic fatigue have a high incidence of premorbid and concurrent psychiatric disorders, and on physical examination many often have reproducible tender points similar to fibromyalgic patients. Clinical evaluation should rule out other potential causes of fatigue, but elaborate diagnostic tests are seldom required. Presently, no specific treatment exists for CFS. A cognitive behavioral approach with or without the use of tricyclics has been advocated. Patients should be encouraged to maintain functional status and should not be discouraged from exercise. Several medications have been tried but with no definite clinical benefit.