Multiple chemical sensitivity

Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is a complex chronic condition symptoms characterized by non-specific symptoms that the affected person attributes to encountering small amounts of common substances, such as perfume. The etiology, diagnosis and treatment of MCS are controversial and still debated among researchers, but a 2018 review concluded that a hyperactive limbic system and autonomic nervous system were confirmed features of the condition. A 2018 systematic review concluded that the evidence suggests that organic abnormalities in sensory processing pathways and the limbic system combined with some specific, uncommon personality traits (such as heightened attentional bias) best explains this condition. Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is a complex chronic condition symptoms characterized by non-specific symptoms that the affected person attributes to encountering small amounts of common substances, such as perfume. The etiology, diagnosis and treatment of MCS are controversial and still debated among researchers, but a 2018 review concluded that a hyperactive limbic system and autonomic nervous system were confirmed features of the condition. A 2018 systematic review concluded that the evidence suggests that organic abnormalities in sensory processing pathways and the limbic system combined with some specific, uncommon personality traits (such as heightened attentional bias) best explains this condition. Commonly attributed substances for MCS symptoms include scented products, pesticides, plastics, synthetic fabrics, smoke, petroleum products, and paint fumes. MCS symptoms are typically vague and non-specific. They may include fatigue, headaches, nausea, and dizziness. Although the symptoms of MCS themselves are real, and can be disabling, MCS is not recognized as a separate, discrete disease by the World Health Organization, American Medical Association, or by several other professional medical organizations. Some blinded clinical trials have shown that the study subjects reacted as often and as strongly to placebos as they did to chemical stimuli and that the presence of symptoms was related to the perception that a chemical stimulus was present. Some experts attribute the symptoms to depression, somatoform disorders, or anxiety disorders.