Chemical Intolerance in Primary Care Settings: Prevalence, Comorbidity, and Outcomes

David A. Katerndahl; Iris R. Bell; Raymond F. Palmer; Claudia S. Miller

doi:10.1370/afm.1346

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Idiopathic Environmental Intolerance
Herman Staudenmayer

Published on: 30 July 2012
Chemical Intolerance in Family Medical Practices
Richard L. Doty

Published on: 15 July 2012

Published on: (30 July 2012)
Page navigation anchor for Idiopathic Environmental Intolerance
Idiopathic Environmental Intolerance
Herman Staudenmayer, PhD Clinical Psychologist
Katerndahl, Bell, Palmer, and Miller (2012) state their fundamental presupposition that what they describe as chemical intolerance is explained by a process referred to as toxic-induced loss of tolerance. This is no more than a relabeling of unsubstantiated clinical ecology theory.
Idiopathic Environmental Intolerance (IEI) is a descriptor originating from a 1996 Berlin workshop convened by the International Program o...
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Katerndahl, Bell, Palmer, and Miller (2012) state their fundamental presupposition that what they describe as chemical intolerance is explained by a process referred to as toxic-induced loss of tolerance. This is no more than a relabeling of unsubstantiated clinical ecology theory.
Idiopathic Environmental Intolerance (IEI) is a descriptor originating from a 1996 Berlin workshop convened by the International Program on Chemical Safety of the World Health Organization (IPCS/WHO)[1]. The designation IEI should displace the term multiple chemical sensitivity (MCS) as well as other labels such as environmental illness and chemical intolerance because they suggest unproven causation and physiological mechanisms. IEI is a descriptor without any implication of chemical etiology, immunological sensitivity or susceptibility. Among the professional organizations that have presented position papers concluding that the theories and methodologies advocated by proponents of the toxicogenic theory are unproven and unsubstantiated are the American Academy of Allergy Asthma and Immunology,[2] the American College of Occupational and Environmental Medicine (ACOEM),[3] the American Medical Association,[4] the American College of Physicians,[5] the Royal College of Physicians,[6] the International Society of Regulatory Toxicology and Pharmacology,[7] as well as the IPCS/WHO. The American Academy of Clinical Toxicology,[8] the largest organization in the world devoted to this discipline, has endorsed the ACOEM position statement.
The authors suggest that causation, whether toxicogenic or psychogenic, should not be the focus of discussion for family practice physicians. They suggest an interactive approach which assumes psychiatric symptoms are associated with chemical intolerance. Such an interactive theory requires first validating toxicogenic theories, which has not been accomplished. The authors state that they have a validated self-report instrument to assess chemical intolerance, but chemical intolerance itself remains without validation. The inventory more likely reflects the beliefs individuals have about chemical intolerance. The findings in this study demonstrate a strong correlation between self-rated chemical intolerance and psychiatric conditions. This is consistent with the psychogenic theory, in that psychological processes are sufficient to explain the results in this study. The authors misrepresent the contention that IEI is a somatoform disorder by focusing on one of the DSM-IV somatoform classifications, namely, somatization disorder, that has a diagnostic criterion that the age of onset is before age 30. There are other DSM-IV somatoform diagnostic classifications that do not have an age of onset requirement and have criteria that fit individuals claiming chemical intolerance. The results of this study confirm that somatoform disorders are among the psychiatric conditions reported by individuals with high scores on the chemical intolerance inventory.
Correct assessment has implications for treatment. Psychological treatment is the most appropriate for individuals presenting with IEI. Physicians who accept chemical intolerance as a physical condition unwittingly or intentionally reinforce the belief of the individual, which can interfere with proper psychological treatment. Family Medicine Physicians need to consider the risk of iatrogenic harm when evaluating individuals who self-report chemical intolerances that are not explained by substantiated methods such as those employed to diagnose allergy.
References
1. International Programme on Chemical Safety/World Health Organization (IPCS/WHO). Conclusions and recommendations of a workshop on multiple chemical sensitivities (MCS). Regul Toxicol Pharmacol 1996;24:S188-9.
2. American Academy of Allergy Asthma and Immunology. Board of Directors position statement: idiopathic environmental intolerances. J Allergy Cloin Immunol 1999;103:36-40.
3. American College of Occupational and Environmental Medicine. Multiple chemical sensitivities: idiopathic environmental intolerance. Position statement. ACOEM Report 1999 Jun:1-3.
4. American Medical Association. Council on Scientific Affairs Report: clinical ecology. JAMA 1992;268(24):3465-7.
5. American College of Physicians. Position paper: clinical ecology. Ann Intern Med 1989;111:168-78.
6. Royal College of Physicians. Allergy, conventional and alternative concepts. Report by the Committee on Clinical Immunology and Allergy. London: Royal College of Physicians, 1992.
7. International Society of Regulatory Toxicology and Pharmacology (ISRTP). Report of the Board. Regul Toxicol Pharmacol 1993;18:79.
8. American Academy of Clinical Toxicology. Board of Trustees minutes. 2000 March 29.
Competing interests: None declared
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Competing Interests: None declared.
Published on: (15 July 2012)
Page navigation anchor for Chemical Intolerance in Family Medical Practices
Chemical Intolerance in Family Medical Practices
Richard L. Doty, Director
I welcome this opportunity to comment on this very interesting article by Katerndahl et al. A number of patients report experiencing chronic symptoms they attribute to exposure to environmental chemicals. Such complaints defy traditional diagnostic classification and frequently include a subset of affective, musculoskeletal, gastrointestinal, genitourinary, and cardiovascular symptoms. Since the early 1960's, attempt...
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I welcome this opportunity to comment on this very interesting article by Katerndahl et al. A number of patients report experiencing chronic symptoms they attribute to exposure to environmental chemicals. Such complaints defy traditional diagnostic classification and frequently include a subset of affective, musculoskeletal, gastrointestinal, genitourinary, and cardiovascular symptoms. Since the early 1960's, attempts at classifying such patients into a common nosiology, such as "chemical hypersensitivity", have been controversial and wanting, reflecting, in part, evidence of a psychogenic overlay and the lack of congruence between patient complaints and objective test measures.
As pointed out by the authors, patients with such complaints present to physician's offices in large numbers and clearly experience decreased quality of life. Largely because of lack of resolution of their symptoms, they repeatedly seek help and disproportionately burden the American health care system. In this study, Katerndahl and associates administered two sets of questionnaires sensitive to reports of such symptoms to 400 patients attending family medicine clinics in San Antonio, Texas. A fifth of the sample met the criteria for what they term "chemical intolerance", as defined by questionnaire responses. Interestingly, this group, relative to those with no such symptoms, reported significantly higher rates of comorbid allergies, depression, somatization, alcohol abuse, and both anxiety and panic disorders. The questionnaire scores suggestive of chemical intolerance were correlated with the total number of possible mental disorders. Importantly, after controlling for comorbid psychiatric conditions, the two groups differed significantly only in regards to social activities.
This study is of particular interest on several grounds. First, the study group was largely comprised of Latin Americans, a group that has been underrepresented in earlier studies on this topic. Second, this study further supports the view that the etiology of many, if not most, of these patients has psychiatric origins. Third, this work shows that socioeconomic status may be a factor associated with such complaints, conceivably reflecting greater exposures in work-related situations. Fourth, this study reiterates the fact that most patients with complaints of chemical intolerance, regardless of etiology, find their problem very debilitating.
Despite such reaffirmation, however, the challenge remains for differentiating psychological from physical factors in patients reporting somatic alterations from exposures to environmental chemicals which are not demonstrable through traditional means. This study, although not definitive, is a step in this direction.
Competing interests: None declared
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Competing Interests: None declared.