2015 IOM criteria The
IOM criteria come from the IOM's 2015 report on CFS, and the CDC currently uses this definition. The IOM criteria require the following three symptoms: • Severe, disabling fatigue of new onset • Post-exertional malaise (PEM) •
Unrefreshing sleep. Also, at least one of the following is required: • Cognitive impairment •
Orthostatic intolerance They also note that for all symptoms except orthostatic intolerance, "frequency and severity of symptoms should be assessed", and that these symptoms should be present at least half the time with at least moderate severity.
CDC 1994 criteria The 1994 research guidelines were proposed by the "International Chronic Fatigue Syndrome Study Group", led by the
Centers for Disease Control and Prevention. The criteria were described as the most widely used diagnostic criteria for CFS in 2007. These criteria are sometimes called the "Fukuda definition" after the first author (
Keiji Fukuda) of the publication. The 1994 CDC criteria specify the following conditions must be met: ;Primary symptoms Clinically evaluated, unexplained, persistent or relapsing chronic fatigue that is: • of new or definite onset (has not been lifelong); • is not the result of ongoing exertion; • is not substantially alleviated by rest; and • results in substantial reduction in previous levels of occupational, educational, social, or personal activities. ;Additional requirements The concurrent occurrence of four or more of the following symptoms, all of which must have persisted or recurred during six or more consecutive months of illness and must not have predated the fatigue: • self-reported impairment in
short-term memory or
concentration severe enough to cause substantial reduction in previous levels of occupational, educational, social, or personal activities; •
sore throat; • tender cervical or axillary
lymph nodes; •
muscle pain; • multi-
joint pain without joint swelling or redness; •
headaches of a new type, pattern, or severity; •
unrefreshing sleep; • post-exertional malaise lasting more than 24 hours. ;Final requirement All other known causes of chronic fatigue must have been ruled out, specifically clinical depression, side effects of medication, eating disorders and substance abuse. The clinical evaluation should include: • A thorough history that covers medical and psychosocial circumstances at the onset of fatigue; depression or other psychiatric disorders; episodes of medically unexplained symptoms; alcohol or other substance abuse; and current use of prescription and over-the-counter medications and food supplements; • A mental status examination to identify abnormalities in mood, intellectual function, memory, and personality. Particular attention should be directed toward current symptoms of depression or anxiety, self-destructive thoughts, and observable signs such as psychomotor retardation. Evidence of a psychiatric or neurologic disorder requires that an appropriate psychiatric, psychological, or neurologic evaluation be done; • A thorough physical examination; • A minimum battery of laboratory screening tests, including complete blood count with leukocyte differential; erythrocyte sedimentation rate; serum levels of alanine aminotransferase, total protein, albumin, globulin, alkaline phosphatase, calcium, phosphorus, glucose, blood urea nitrogen, electrolytes, and creatinine; determination of thyroid-stimulating hormone; and urinalysis. Other diagnostic tests have no recognized value unless indicated on an individual basis to confirm or exclude a differential diagnosis, such as
multiple sclerosis.
CDC 1988 criteria The initial chronic fatigue syndrome definition was published in 1988. It is also called the "Holmes definition", after the manuscript's first author. The Homes criteria require these two points: • Debilitating fatigue of new onset which interferes with the patient's daily activities • Other fatiguing conditions must be eliminated They define 11 symptom criteria: • Mild fever (oral temperature between 37.5 °C and 38.6 °C) or chills • Sore throat • Sore lymph nodes • Muscle weakness • Muscle discomfort or myalgia • Fatigue after exercise lasting at least 24 hours • Headaches • Joint pain • Hypersomnia or insomnia • A rapid onset over a few hours or days And three physical criteria that must be documented by a physician: • Low-grade fever (37.6 °C and 38.6 °C, or rectal temperature between 37.8 °C and 38.8 °C) • Nonexudative pharyngitis • Tender lymph nodes To make a diagnosis, a patient must meet either 8 of the 11 symptom criteria, or 6 of the 11 symptom criteria and 2 of 3 physical criteria. and include both CFS of unknown etiology and a subtype of CFS called post-infectious fatigue syndrome (PIFS), which "either follows an infection or is associated with a current infection". The Oxford criteria defines CFS as follows: • Fatigue must be the main symptom • There must be a definite onset • The fatigue must be debilitating • The fatigue must have lasted for 6 months or longer, and be present at least 50% of the time • Other symptoms are possible, such as muscle pain, mood problems, or sleep disturbance • Conditions known to cause severe fatigue and some mental conditions exclude a diagnosis. Post-infectious fatigue syndrome also requires evidence of a prior infection. The requirements are summarized as follows: • Severe fatigue • "Post-Exertional Malaise and/or Fatigue" • Sleep dysfunction • Myalgia • Two or more neurological or cognitive symptoms • At least one symptom from the lists for two of these categories: • Autonomic symptoms • Neuroendocrine symptoms • Immune symptoms • Symptoms must be present for at least 6 months In light of the advances in understanding of ME and CFS, the criteria for ME as described by
Ramsay and others were updated in 2009. These have been cited in articles and are being evaluated as of 2011, for example, in studies to ascertain differences between patients selected using different case definitions.
International Consensus Criteria The International Consensus Criteria were based on the Canadian consensus criteria and developed by a group of 26 individuals from 13 countries and consisting of clinicians, researchers, teaching faculty, and an independent patient advocate. The ICC define the illness as: • "Postexertional neuroimmune exhaustion" or PENE • Neurological symptoms: patients must have at least one symptom from one of the four lists: • Neurocognitive impairments • Pain • Sleep disturbance • "Neurosensory, perceptual and motor disturbances" • Immune, gastrointestinal and genitourinary symptoms: patients must have at least one symptom in three of five areas: • Flu-like symptoms • Gets sick from viruses easily • Gastro-intestinal symptoms • Genitourinary symptoms • Sensitivity to food, medicines, or chemicals • Energy production symptom: patients must have at least one symptom from any of the four lists • Cardiovascular symptoms • Respiratory symptoms • Temperature dysregulation • Intolerance of heat or cold The ICC definition also notes that children may have somewhat different symptoms, and that symptoms tend to be more variable. ==National guidelines==