As a consequence of his insistence upon his own, non-standard definition of allergy and his unusual theories about how the immune system and toxins affect people, the ideas he promoted were widely rejected, and clinical ecology emerged as a non-recognized medical specialty.Since the 1950s, many hypotheses have been advanced for the science surrounding multiple chemical sensitivity.In the 1990s, an association was noted with chronic fatigue syndrome, fibromyalgia, and Gulf War syndrome.In 1994, the AMA, American Lung Association, US EPA and the US Consumer Product Safety Commission published a booklet on indoor air pollution that discusses MCS, among other issues. The booklet further states that a pathogenesis of MCS has not been definitively proven, and that symptoms that have been self-diagnosed by a patient as related to MCS could actually be related to allergies or have a psychological basis, and recommends that physicians should counsel patients seeking relief from their symptoms that they may benefit from consultation with specialists in these fields.In 1995, an Interagency Workgroup on Multiple Chemical Sensitivity was formed under the supervision of the Environmental Health Policy Committee within the United States Department of Health and Human Services to examine the body of research that had been conducted on MCS to that date. The work group included representatives from the Centers for Disease Control and Prevention, United States Environmental Protection Agency, United States Department of Energy, Agency for Toxic Substances and Disease Registry, and the National Institutes of Health.
Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is an unrecognized and controversial diagnosis characterized by chronic symptoms attributed to exposure to low levels of commonly used chemicals. Symptoms are typically vague and non-specific. They may include fatigue, headaches, nausea, and dizziness. Although these symptoms can be debilitating, MCS is not recognized as an organic, chemical-caused illness by the World Health Organization, American Medical Association, nor any of several other professional medical organizations. Blinded clinical trials show that people with MCS react as often and as strongly to placebos as they do to chemical stimuli; the existence and severity of symptoms is seemingly related to the perception that a chemical stimulus is present.Commonly attributed substances include scented products (e.g. perfumes), pesticides, plastics, synthetic fabrics, smoke, petroleum products, and paint fumes. Symptoms
Symptoms are typically vague and non-specific, such as fatigue or headaches. These symptoms, although they can be disabling, are called non-specific because they are not associated with any single specific medical condition. A 2010 review of MCS literature said that the following symptoms, in this order, were the most reported in the condition: headache, fatigue, confusion, depression, shortness of breath, arthralgia, myalgia, nausea, dizziness, memory problems, gastrointestinal symptoms, respiratory symptoms.Symptoms mainly arise from the autonomic nervous system (such as nausea or dizziness) or have psychiatric or psychological aspects (such as difficulty concentrating).