Section 25. Special Subjects

Chapter 306. Diseases of Unknown Cause

Topics: Introduction | Chronic Fatigue Syndrome | Gulf War Syndrome | Multiple Chemical Sensitivity Syndrome | Sick Building Syndrome

Multiple Chemical Sensitivity Syndrome

Multiple chemical sensitivity syndrome is a disorder that appears to be triggered by low-level exposure to multiple chemical substances commonly found in the environment.

Multiple chemical sensitivity syndrome is more common among women than men. In addition, 40% of people with chronic fatigue syndrome and 16% of people with fibromyalgia have multiple chemical sensitivity syndrome as well.

Some doctors consider this disorder to be psychologic in cause, probably a type of anxiety disorder similar to agoraphobia (fear of going out in public) or a panic attack (see Section 7, Chapter 100). Others believe the disorder may be a type of allergic reaction (see Section 16, Chapter 185). Indeed, various changes in the immune system may occur, supporting the idea of an allergic reaction. However, there is no consistent pattern of such changes among people who have this syndrome, and the cause remains unknown.

See the sidebar Reported Triggers for Multiple Chemical Sensitivity Syndrome.

Symptoms and Diagnosis

Some people start having symptoms after a single exposure to high levels of various toxic substances. Sufferers blame their symptoms on exposure to these substances, but evidence is usually lacking.

Symptoms include a rapid heart rate, chest pain, sweating, shortness of breath, fatigue, flushing, dizziness, nausea, choking, trembling, numbness, coughing, hoarseness, and difficulty concentrating.

A doctor makes the diagnosis of multiple chemical sensitivity based on the symptoms. The diagnosis is supported if the symptoms recur after repeated exposure to the chemical substance; recur after exposure to levels much lower than those that have been tolerated previously or that are commonly tolerated by others; subside when the person leaves the offending environment; and develop in response to a wide variety of unrelated chemical substances.

A blood test may be performed to measure red and white blood cell counts and antibody levels but is of no proven value.

Treatment

Treatment usually involves trying to avoid the toxic substances thought to cause the symptoms. However, avoidance may be difficult, because many of these substances are widespread. Psychotherapy is sometimes helpful.