Multiple chemical sensitivity can include a wide range of symptoms, which some people link to their environment. It's also known as “environmental illness,” "sick building syndrome,” or “MCS.” Your doctor may call it “idiopathic environmental intolerance.”
The symptoms people report are wide-ranging. They include headache, fatigue, dizziness, nausea, congestion, itching, sneezing, sore throat, chest pain, changes in heart rhythm, breathing problems, muscle pain or stiffness, skin rash, diarrhea, bloating, gas, confusion, trouble concentrating, memory problems, and mood changes.
Possible triggers that set off people's symptoms vary a lot, too. They include tobacco smoke, auto exhaust, perfume, insecticide, new carpet, chlorine, and more.
Those feelings are real. But they can happen for many reasons. The question is whether MCS is an illness. Health experts don’t agree on that. The American Medical Association doesn’t consider multiple chemical sensitivity to be an illness.
Causes
There is no question that high doses of some chemicals make people sick and that irritants such as pollution and cigarette smoke worsen conditions like asthma. How very low levels of chemical exposure affect people isn't clear.
Some doctors suggest it's an immune response similar to allergies. Others say that the symptoms stem from an extreme sensitivity to certain smells. It's possible that conditions such as depression and anxiety play a role, too.
In some cases, people point to a major event, like a chemical spill. Or they may link their symptoms to contact with low levels of chemicals at work, such as if their office has poor ventilation.
Some say that levels of exposure generally considered safe for most people can have an effect on a few.
Diagnosis and Treatment
There are no reliable tests to diagnose multiple chemical sensitivity, and there are no effective or proven treatments.
Some doctors prescribe antidepressants, including “SSRIs” (selective serotonin reuptake inhibitors) such as citalopram (Celexa), fluoxetine (Prozac), and paroxetine (Paxil).
Other people find that medicines for anxiety and sleep help. It may also help to treat specific symptoms, such as headaches.
People often find solutions on their own. Some learn from experience that certain foods or chemicals seem to make their symptoms worse. Avoiding those things may help. But going on very strict diets, avoiding any possible allergens and pollutants, or even quitting your job are a big burden.