If you don't know what the illness is, then any name will do (with apologies to Alice's Adventures in Wonderland, Lewis Carroll). In this issue of American Family Physician, Magill and Suruda¹ use the term “multiple chemical sensitivity” to identify a baffling constellation of symptoms without a clear origin other than the sufferer's declaration that it is caused by exposure to chemicals—most commonly man-made chemicals. However, at least 20 other monikers have been given to this clinical phenomenon. Another name, recently suggested by the American Academy of Allergy, Asthma, and Immunology,² can be added to the list: “idiopathic environmental intolerance.”

This newly named clinical phenomenon has three defining characteristics: (1) it is an acquired disorder with multiple recurrent symptoms; (2) it is associated with diverse environmental factors tolerated by the majority of other people; and (3) it is not explained by any known medical, psychiatric or psychologic disorder. The reader can appreciate that if a clinical condition has a multitude of names, a pantheon of symptoms, numerous pathophysiologic explanations and numerous nontraditional treatment regimens, then confusion abounds. So as not to further contribute to the confusion of names, I will use the term “multiple chemical sensitivity.”

Symptoms of multiple chemical sensitivity include, but are not limited to, headache, loss of consciousness, poor memory, palpitations, shortness of breath, dizziness, joint pain and fatigue. These symptoms did not originate with multiple chemical sensitivity. They were common to a disease frequently encountered in the previous century—neurasthenia. Thus, the constellation of symptoms described for multiple chemical sensitivity is not new and perhaps this is not a new phenomenon.

In her most recent book, Hystories: Hysterical Epidemics and Modern Media, Elaine Showalter³ lists three ingredients for the formation of hysterical epidemics:

1. A physician or other authority figure who will define, name and publicize the disorder that attracts patients to the community.

2. Vulnerable patients with confusing symptoms who are dissatisfied with their current treatment.

3. A supportive cultural environment that may have activist leadership.

Although this explanation may not fully apply to multiple chemical sensitivity, undoubtedly the discriminating physician must include the impact of psychosocial elements when evaluating these patients.

In addition to the numerous chemical, hormonal, immunologic and neurologic assessments performed by the clinical ecologists, a new “objective” tool has been added to their armamentarium—the single photon emission computed tomography (SPECT) scan. During the past five years, we have seen a growing percentage of patients with previously diagnosed multiple chemical sensitivity or a similar diagnosis who had undergone SPECT scans. All of the results in these patients were positive, with the most common diagnosis being chemically induced toxic encephalopathy.

Fincher and colleagues⁴ report their experience with SPECT scans in 25 patients with mixed solvent exposure. All of these patients had positive results. However, even a superficial review of the article reveals numerous technical and procedural flaws. In a review of this article, Franzblau and contributors⁵ found that the study was poorly designed and executed with numerous problems that created confounders or bias, and the conclusions were not supported by the data.

Perhaps of more significance is the position of the Society of Nuclear Medicine Brain Imaging Council⁶ that SPECT scans cannot detect brain abnormalities produced by chemicals. In the several cases in which we repeated SPECT scans in the patients in our clinic whose previous scans were purported to show toxic encephalopathy, the results in each case were normal.

Multiple chemical sensitivity is not simply a medical concern of diagnosis and treatment, but it is becoming a major social and economic issue with a strong activist agenda. In their book, Chemical Sensitivity: The Truth About Environmental Illness, Barrett and Gots⁷ address this issue. Advocates of multiple chemical sensitivity have successfully sought sympathy and support by attacking the chemical industry and others as the source of their plight. Numerous activist organizations publish newsletters and maintain Web sites that identify physicians and lawyers who support the chemical causality of their illnesses. A newsletter reports legislative, public policy and court decisions that support multiple chemical sensitivity as a legitimate disease or disability.⁸ Thus, multiple chemical sensitivity may become a disease by a legal fiat.

In 1991, multiple chemical sensitivity was defined as a disability under the Americans with Disability Act. This has resulted in the demand for accommodation at work, at school and in housing for those with a diagnosis of multiple chemical sensitivity. In some states, multiple chemical sensitivity is recognized under workers' compensation laws as a disability resulting in free health care for persons with symptoms related to the phenomenon, as well as payment for lost wages. Because a major treatment recommendation is avoidance of chemical exposure, the worker may never return to active employment.

There is activist litigation against manufacturers of carpet, paint, household cleaning products, etc. These multimillion dollar lawsuits have been curtailed by the 1993 U.S. Supreme Court decision, Daubert versus Merrell Dow, which has given trial judges authority to exclude unscientific testimony.⁹ This decision has been used successfully in ruling that multiple chemical sensitivity is not a recognized clinical entity. However, this ruling does not exclude the possibility that the constellation of symptoms will reappear under another name.

The increased diagnosis of multiple chemical sensitivity may reflect a national increase in the use of alternative health care providers. Recent studies have shown prevalent use of alternative health care. A survey¹⁰ of more than 1,000 individuals that investigated the use of alternative health care, health status, and values and attitude toward conventional medicine revealed a number of interesting responses. The majority of such users were not singularly dissatisfied with standard medical practice, but found health care alternatives to be more in agreement with their own values, beliefs and philosophic views toward health and life.

Family physicians with orientation in the biopsychosocial model are positioned to provide care for patients who fit this profile of multiple chemical sensitivity. Magill and Suruda¹ repeatedly emphasize that the physician must be compassionate and understanding. However, the physician must not contribute to the patient's belief system of illness. This approach would not only reinforce avoidance of the multitude of chemicals blamed for the illness, but would also reinforce avoidance of social contacts, family and the work setting, resulting in further isolation and inward focusing on the illness status. The use of both behavioral and pharmacologic treatment modalities may prove useful in dealing with some of the reported causes for this phenomenon, including psychosocial factors, phobic behavior, panic attacks, hyperventilation, conditioned olfactory responses and true allergy. For the treating physician, these patients will be among their most challenging.