In the 1990s, behaviors exhibited by MCS sufferers were hypothesized by some to reflect broader sociological fears about industrial pollution and broader societal trends of technophobia and chemophobia.These theories have attracted criticism.In Canada, in 2017, following a three-year government inquiry into environmental illness, it was recommended that a public statement be made by the health department.A 2018 systematic review concluded that the evidence suggests that abnormalities in sensory processing pathways combined with peculiar personality traits best explains this condition. Diagnosis
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 chemicals, foods, or inhalants. None of these tests correlate with MCS symptoms, and none are useful for diagnosing MCS.The stress and anxiety experienced by people reporting MCS symptoms are significant. Neuropsychological assessments do not find differences between people reporting MCS 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.
Healthcare providers can provide useful education on the bodys natural ability to eliminate and excrete toxins on its own and support positive self-care efforts. Avoiding triggers, such as by removing smelly cleaning products from the home, can reduce symptoms and increase the persons sense of being able to reclaim a reasonably normal life. However, for other people with MCS, their efforts to avoid suspected triggers will backfire, and instead produce harmful emotional side effects that interfere with the overall goal of reducing distress and disability. Treatments that have not been scientifically validated, such as detoxification, have been used by MCS patients. Unproven treatments can be expensive, may cause side effects, and may be counterproductive. Epidemiology
Prevalence rates for MCS vary according to the diagnostic criteria used. The condition is reported across industrialized countries and it affects women more than men. : 37 In 2018, the same researchers reported that the prevalence rate of diagnosed MCS had increased by more than 300% and self-reported chemical sensitivity by more than 200% in the previous decade. They found that 12.8% of those surveyed reported medically diagnosed MCS and 25.9% reported having chemical sensitivities.A 2014 study by the Canadian Ministry of Health estimated, based on its survey, that 0.9% of Canadian males and 3.3% of Canadian females had a diagnosis of MCS by a health professional. : 37 While a 2018 study at the University of Melbourne found that 6.5% of Australian adults reported having a medical diagnosis of MCS and that 18.9 per cent reported having adverse reactions to multiple chemicals.