MCS is a complex condition. The term describes a wide range of debilitating symptoms linked to low level chemical exposure. Symptoms can be minor (eg sore eyes) to life threatening (eg seizures, respiratory problems and loss of consciousness). It is known by a variety of names, including Environmental Illness, Toxicant Induced Loss of Tolerance and Toxic Injury. There are different names because there are differing ideas about the way in which the symptoms are produced in a patient and because MCS is not currently an internationally classified disorder. This is partly because there is not medical agreement about its mechanisms, diagnosis and treatment.

It is often described as a chronic condition in which symptoms occur again and again in response to low level chemical exposure and multiple unrelated chemicals. More than one organ in the sufferer’s body is affected by the exposure and symptoms improve when the chemicals are removed.

People with MCS may be affected by exposure to everyday chemicals such as those found in pesticides, cleaning and personal care products, perfume, cigarette smoke, car exhausts, new carpets, fresh paint and printing and office products.

Current treatments tend to focus on avoiding contact with trigger chemicals and dietary changes and supplements. Some people use medicines referred to as Mast Cell Stabilizers, and certain other antihistamines which may dull the response to chemicals.

Further information:

MSC America information about MCS 
Chemical Sensitivity and MCS
MCS: Key Research Needs – an Australian Scientific Review 
Allergy, Sensitivity & Environmental Health Association Qld Inc – a self-help, voluntary support group