Multiple Chemical Sensitivity

by Cathy Wong

When Shawna Doherty, a 46-year old mural artist, was told that she may have multiple chemical sensitivities (MCS), she was relieved. The symptoms she was experiencing, such as unexplained fatigue, baffled her doctors. They could not pin down the cause after repeated laboratory tests. One doctor even suggested that she “just needed to get out more”. Finally, Shawna was referred to a doctor specializing in environmental medicine who believes the cause of her illness stems from a sensitivity to the chemicals in the paint she works with.

MCS is a relatively new and controversial diagnosis. Exactly how it affects the body is not yet known and is just starting to be studied. Some critics in the medical community, however, dismiss it as being essentially a psychological disorder with physical manifestations.

MCS is diagnosed after alternative reasons for the symptoms, such as cancer and other illnesses, have been ruled out. A person with MCS often has a history of chemical exposure. After the initial exposure, he or she may become increasingly sensitive to an array of foods and chemicals at levels that would not cause the same reaction in an ordinary person.

Symptoms of MCS were recently studied by the government-funded Nova Scotia Environmental Health Center, a clinic that receives patients only by referral from medical doctors. The Center mailed 812 of its patients questionnaires about their symptoms. The questionnaire consisted of a general health and lifestyle history, the nature, frequency, and intensity of the symptoms, whether or not the symptoms worsened after an identified exposure, the limitations in daily activities from illness, and additional illnesses the patient had. Out of the 812 questionnaires, 384 (47%) were returned. 

The top symptoms reported by the patients were:

• altered sense of smell

• fatigue, very tired, without energy

• tiredness not relieved by rest or sleep

• usually acceptable odors were sickening

• trouble seeing at night*

• bruise easily*

• sensitive to temperature change*

* these symptoms occurred after chemical exposure

Although the poor response rate may have biased the results, this report increases our understanding of  the type, frequency, and severity of the most common symptoms of MCS. Further studies are needed to establish the validity of this syndrome and to develop treatment protocols, especially considering the constant introduction of new chemicals into our environment.

References

1. Joffres MR, Williams T, Sabo B, Fox, RA.  Environmental Sensitivities: Prevalence of Major Symptoms in a Referral Center:  The Nova Scotia Environmental Sensitivities Research Center Study.  Environmental Health Perspectives 2001;109:161-165.