Multiple Chemical Sensitivity

What is multiple chemical sensitivity?

Multiple chemical sensitivity (MCS) is when a person has a negative reaction when they touch or smell certain chemicals. Exposure to trace amounts of common or everyday chemicals typically doesn’t cause any symptoms or allergic reactions. But, for people with MCS, exposure to even the tiniest amounts of chemicals found in things like beauty products, cleaning products or gasoline exhaust can trigger adverse reactions. It’s important to note that the chemicals that cause a reaction are below the levels that are considered harmful or toxic to the general population.

Other names for MCS include:

• Chemical sensitivities.
• Environmental illness.
• Total allergy syndrome.
• Idiopathic environmental intolerance.

Healthcare providers disagree on whether MCS should be classified as a medical condition. Still, you should talk to a healthcare provider if you believe certain substances in your environment are causing you to feel sick.

Just because MCS isn’t recognized officially doesn’t mean your symptoms aren’t real or that you’re faking an illness. It means that the medical community can’t agree on what an MCS diagnosis means. A compassionate healthcare provider will listen to your concerns and work with you on ways you can feel better.

Is multiple chemical sensitivity a real thing?

The American Medical Association, the American Academy of Allergy and Immunology and the American College of Physicians don’t currently recognize MCS as a condition. It’s a controversial issue. Some healthcare providers believe symptoms of MCS involve a combination of environmental and psychological factors. Others believe MCS should be classified as a medical condition, and that exposure to tiny amounts of everyday chemicals can produce physical symptoms in certain people. But clinical trials and studies haven’t found a cause-effect relationship between low levels of chemical substances and the symptoms people report.

Who gets MCS?

Studies show MCS is more common in people assigned female at birth (AFAB) between 30 and 50 years old.

What are the symptoms of chemical sensitivity syndrome?

Some common symptoms that people with multiple chemical sensitivity experience include:

• Skin rashes.
• Nausea or vomiting.
• Bloating, gas, diarrhea.
• Confusion or memory loss.
• Asthma or trouble breathing.
• Fatigue.
• Joint pain or muscle aches.
• Changes in heart
• Sneezing, congestion and sore throat.

People can experience symptoms after chronic, long-term exposure or immediately after a single exposure. Some people have symptoms that interfere with their social lives and with work.

In fact, one study of 35 people with MCS found the following:

• 97% of the people stopped doing activities outside their homes.
• 97% of the people stopped using cleaning products.
• 94% of the people stopped using products with fragrances.
• 91% of the people changed their eating habits.
• 77% of the people quit their jobs.

What are the stages of MCS?

Some researchers classify MCS into two phases: sensitization and triggering.

Sensitization refers to symptoms that appear due to an exposure to a single chemical or stimulus. An example of this phase would be if a person begins to vomit after smelling air freshener in a bathroom.

Triggering refers to symptoms that spread to a larger group of chemicals or affect other parts of your body. In this phase, the same person above could begin vomiting when they smell perfume, deodorant or another product that resembles the air freshener in the bathroom. In this instance, the trigger now contains perfume, deodorant and air freshener. Or, in addition to vomiting, the person may also feel dizzy when they smell air freshener. The original symptom was vomiting, but now a second symptom is dizziness.

What causes MCS?

Healthcare providers all agree that certain chemicals, substances or environmental irritants can cause a person to feel sick or intensify existing conditions like asthma. But the exact reason why very low levels of chemicals can make someone sick isn’t known.

According to the American Academy of Family Physicians, the most common chemicals that cause symptoms of MCS are:

• Air fresheners/deodorizers and furniture or floor cleaning products.
• Deodorants, perfumes, colognes.
• Smoke from cigars and cigarettes.
• Asphalt pavement or fumes from tar.
• Fumes from fossil fuels like diesel and gasoline.
• Nail polish and nail polish remover.
• Varnish, shellac and lacquer.
• Paint thinner and oil-based paint thinners.
• Ink in pens or on newspapers or magazines.

How is multiple chemical sensitivity diagnosed?

There aren’t any tests to diagnose MCS or any proven treatment methods. Your healthcare provider will listen to your symptoms and try to help you pinpoint what could be causing them. They can also discuss treatments for the specific symptoms you have.

Try to find a compassionate provider who doesn’t dismiss your symptoms and will work with you on how you can feel better. Be cautious of unnecessary or potentially unhelpful tests that aren’t proven to diagnose multiple chemical sensitivities.

How is multiple chemical sensitivity treated?

There aren’t any proven treatments for multiple chemical sensitivity. Your healthcare provider can help you manage your symptoms, but there’s no therapy to treat MCS directly. For example, your healthcare provider can help you manage nausea or skin rashes due to chemical exposure.

While it’s difficult to do, avoiding known triggers or staying away from areas where the chemical exists is one way to try to ease your symptoms. But doing this in a way that doesn’t isolate you or leave you feeling lonely is tricky.

Some healthcare providers believe MCS is related to anxiety and depression and that receiving treatment for those conditions can help. Antidepressants like SSRIs (selective serotonin reuptake inhibitors) or seeing a therapist may be beneficial. This isn’t to say that people with MCS have depression or anxiety, rather that the side effects of MCS can contribute to a person’s emotional and psychological well-being.

When should I see my healthcare provider?

Visit a healthcare provider if you feel uncomfortable symptoms after low-level chemical exposure. While there hasn’t been scientific evidence to prove trace amounts of chemical exposure can cause allergic or toxic symptoms, a caring and understanding provider should be able to help you. Together, you and your provider can get you back to a more normal way of life.

Is MCS an autoimmune disease?

No, MCS isn’t an autoimmune condition.

A note from Cleveland Clinic

It can be quite challenging to live with symptoms of MCS. As humans, we encounter a variety of chemicals and substances constantly throughout the day. While there may not be any known treatment for MCS, having a provider who listens to and supports you can make all the difference. Before you renovate your entire house, move jobs or spend thousands of dollars on ways to feel better, find help from a compassionate healthcare professional. With their help, you can try to find ways to improve your quality of life.