What is multiple chemical sensitivity?
Multiple
chemical sensitivity (MCS) is the name given by some to a condition
in which various symptoms reportedly appear after a person has been
exposed to any of a wide range of chemicals. As a result of their
exposure, people with MCS develop sensitivity and have reactions to
the chemicals even at levels most people can tolerate. Other names
for this condition are "environmental illness" and "sick building
syndrome."
Is MCS a real disorder?
MCS is controversial. Many
recognized medical groups and societies-including the Centers
for Disease Control and Prevention, the American Medical
Association and the American Academy of Allergy, Asthma and
Immunology-do not consider MCS as a distinct physical
disorder. There are several reasons for this.
First, there is a lack of clinical research evidence to support
a physical cause for the symptoms. In addition, people with MCS do
not develop antibodies in response to chemical exposure, as is the
case with an immune system, or allergic, reaction. Further,
patients with MCS also have high rates of mental health disorders,
including depression, anxiety and somatoform disorders (mental
disorders that are expressed through physical symptoms). About 50
percent of people with MCS meet the criteria for depression and/or
anxiety disorders. Much of the controversy, then, centers on
whether the symptoms associated with MCS are caused by physical or
psychological factors.
What are the symptoms of MCS?
MCS may be the only
ailment in existence in which the patient defines both the cause
and the manifestations of his or her own condition. Virtually any
symptom has been attributed to the syndrome, but the symptoms
generally occur in one of three categories: central nervous system
symptoms, respiratory and mucosal irritation, or gastrointestinal
problems. People with MCS have reported a wide range of symptoms,
including:
- Headache
- Fatigue
- Dizziness
- Nausea
- Irritability
- Confusion
- Difficulty concentrating
- Intolerance to heat or cold
- Earache
- Stuffy head or congestion
- Itching
- Sneezing
- Sore throat
- Memory problems
- Breathing problems
- Changes in heart rhythm
- Chest pain
- Muscle pain and/or stiffness
- Bloating or gas
- Diarrhea
- Skin rash or hives
- Mood changes
How common is MCS?
Many health care practitioners
do not recognize MCS as a disorder and, therefore, do not make a
diagnosis of MCS. For this reason, it is not possible to assess how
many people actually suffer from MCS. One estimate suggests that 2
percent to 10 percent of people suffer some disruption in their
lives because of MCS, although other experts believe these
estimates are too high. The U.S. Environmental Protection Agency
reported that about one-third of people working in sealed buildings
claimed to be sensitive to one or more common chemicals. More women
than men claim to have MCS, and it appears to occur most often in
people between the ages of 30 and 50 years.