In practice, diagnosis relies entirely upon the self-reported claim that symptoms are triggered by exposure to various substances. Many other tests have been promoted by various people over the years, including testing of the immune system, porphyrin metabolism, provocation-neutralization testing, autoantibodies, the Epstein–Barr virus, testing for evidence of exposure to pesticides or heavy metals, and challenges involving exposure to<unk> s, foods, or inhalants. None of these tests correlate with<unk>  symptoms, and none are useful for diagnosing<unk> . The stress and anxiety experienced by people reporting<unk>  symptoms are significant. Neuropsychological assessments do not find differences between people reporting<unk>  symptoms and other people in areas such as verbal learning, memory functioning, or psychomotor performance. Neuropsychological tests are sensitive but not specific, and they identify differences that may be caused by unrelated medical, neurological, or neuropsychological conditions. Another major goal for diagnostic work is to identify and treat any other medical conditions the person may have. People reporting<unk> -like symptoms may have other health issues, ranging from common conditions, such as depression or asthma, to less common circumstances, such a documented<unk>  exposure during a work accident. These other conditions may or may not have any relationship to<unk>  symptoms, but they should be diagnosed and treated appropriately, whenever the patient history, physical examination, or routine medical tests indicates their presence. The differential diagnosis list includes solvent exposure, occupational asthma, and allergies. Definitions Different researchers and proponents use different definitions, which complicates research and can affect diagnosis. For example, the 1987 definition that requires symptoms to begin suddenly after an identifiable, documented exposure to a<unk> , but the 1996 definition by the WHO/ICPS says that the cause can be anything, including other medical conditions or psychological factors. In 1996, an expert panel at WHO/ICPS was set up to examine<unk> . The panel accepted the existence of "a disease of unclear pathogenesis", rejected the claim that<unk>  was caused by<unk>  exposure, and proposed these three diagnostic requirements for what they re-named idiopathic environmental intolerances (IEI): # the disease was acquired (not present from birth) and must produce<unk>  relapsing symptoms; #the symptoms must be closely related to<unk>  environmental influences, which are well tolerated by the majority of the population"; and #it could not be explained by any other medical condition. In Japan,<unk>  is called<unk>  hypersensitivity or<unk>  intolerance (化学物質過敏症; kagaku bushitsu kabinsho), and the 1999 Japanese definition requires one or more of four major symptoms – headaches; malaise and fatigue; muscle pain; joint pain – combined with laboratory findings and/or some minor symptoms, such as mental effects or skin conditions. The defined lab findings are abnormalities in parasympathetic nerves, cerebral cortical dysfunction diagnosed by SPECT testing, visuospatial abnormalities, abnormalities of eye movement, or a positive provocation test. International Statistical Classification of Diseases The International Statistical Classification of Diseases and Related Health Problems (ICD), maintained by the World Health Organization, is a medical coding system used for medical billing and statistical purposes – not for deciding whether any person is sick, or whether any collection of symptoms constitutes a single disease. The ICD does not list<unk>  as a discrete disease. However, this does not mean that people with<unk> -related symptoms cannot be treated or billed for medical services. For example, the public health service in Germany permits healthcare providers to bill for<unk> -related medical services under the ICD-10 code T78.4, which is for idiosyncratic reactions, classified under the heading T78, Unerwünschte Nebenwirkungen, anderenorts nicht klassifiziert ("adverse reactions, not otherwise specified"). Being able to get paid for medical services and collect statistics about unspecified, idiosyncratic reactions does not mean that<unk>  is recognized as a specific disease or that any particular cause has been defined by the German government. Healthcare providers can also bill for<unk> -related services under the ICD-10 codes of F45.0 for somatization disorder.<unk>  is named in evidence-based ("S3") guidelines for the management of patients with nonspecific, functional, and somatoform physical symptoms.
Multiple chemical sensitivity
Acute to chronic ratio
Cold sensitivity
Hypoallergenic
Oat sensitivity
Acid-fastness
Vangent
Depurative