Missed diagnoses and misdiagnoses of environmental toxicant exposure. The psychiatry of toxic exposure and multiple chemical sensitivity.

Toxins such as carbon monoxide, lead, and mercury that present occasionally with primarily psychiatric symptoms can pose some of the most difficult diagnoses. This article reviews the clues that can allow the diagnostician to identify the role of one of these substances. Equally important, the article discusses the contentious issues that surround the phenomen known as multiple chemical sensitivity. Viewed primarily as a functional illness, often with legal overtones, this putative disorder is critically reviewed to see if it meets the same demanding standard of validity that is found in the psychiatric symptoms associated with other toxic disorders. Although questioning the strict medical origin of medical chemical sensitivity, the article outlines some treatment hints that may helpful in the management of this difficult group of patients.