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.
Possible causes
Various different causes for MCS have been hypothesized.There is a general agreement among most MCS researchers that the cause is not specifically related to sensitivity to chemicals, but this does not preclude the possibility that symptoms are caused by other known or unknown factors. Various health care professionals and government agencies are working on giving those who report the symptoms proper care while searching for a cause.In 2017, a Canadian government Task Force on Environmental Health said that there had been very little rigorous peer-reviewed research into MCS and almost a complete lack of funding for such research in North America. "Most recently," it said, "some peer-reviewed clinical research has emerged from centres in Italy, Denmark and Japan suggesting that there are fundamental neurobiologic, metabolic, and genetic susceptibility factors that underlie ES/MCS. "The US Occupational Safety and Health Administration (OSHA) says that MCS is highly controversial and that there is insufficient scientific evidence to explain the relationship between any of the suggested causes of MCS – it lists "allergy, dysfunction of the immune system, neurobiological sensitization, and various psychological theories" as the suggested causes – and its symptoms. Immunological
Researchers have studied immunity biomarkers in people with MCS to determine whether MCS could be an autoimmune disorder or allergic response, but the results have been inconclusive. Some people with MCS appear to have excess production of inflammatory cytokines, but this phenomenon is not specific to MCS and overall there is no evidence that low-level chemical exposure causes an immune response.