Multiple Chemical Sensitivity Is Much Underdiagnosed in Primary Care, according to a Recent Study — Comments on the Difficulties Posed by Complexity in Medicine

© 2012 Peter Free

 

12 July 2012

 

 

Citation — to the study that I will briefly discuss

 

David A. Katerndahl, Iris R. Bell, Raymond F. Palmer, and Claudia S. Miller, Chemical Intolerance in Primary Care Settings: Prevalence, Comorbidity, and Outcomes, Annals of Family Medicine 10(4): 357-365 (July-August 2012)

 

 

My theme in regard to this study — medicine struggles, when it has to confront apparent illnesses for which there is no apparently provable cause

 

The question of what to do for patients deepens, when the apparent illness exhibits perhaps explaining psychiatric or psychological disorders.

 

Put tactlessly — which is necessary to make the point — clinical medicine often has trouble dealing with people, who can too cavalierly be described as “pain in the butt” patients.

 

Affected people know with certainty that something is wrong with them, but their evidence-seeking physicians may not.  Frustration on both sides results.

 

 

Three general points about this topic

 

These are:

 

(1) Before something is recognized as mechanistically caused illness, it is easy to discount patients suffering from it.

 

(2) More than most people recognize, physicians included, there is no such thing as a narrow band of medical “normality.”

 

The idea that one is either “sick” or “not sick” is often too black and white.

 

The body’s physiology tends to imitate someone trying to walk a tightrope, with obvious deviations from neutrality being just as much part of the “normal” state as more comfortably upright interludes.

 

This characteristic is more obvious to older people, who experience these “normal” deviations away from feeling good on a daily or weekly basis.

 

Related to this is the idea that individuals among populations also vary across a wide spectrum, regarding their physical and psychological sensitivity to environmental triggers.

 

Character traits, themselves caused by genetics and environment, make up a wide array of what medicine sometimes misidentifies as illnesses.  This too-pat “either or” characterization sometimes misleads us into thinking that something can be easily diagnosed, managed, or cured.

 

(3) How a physician defines his/her role in treating patients often determines the way in which he or she will respond to apparently ill-founded patient complaints.

 

For example, physicians who define their medical role as one that ameliorates “suffering” will be more receptive to patients, who have ambiguous and poorly understood medical complaints.  These people are, after all, still dis-eased.

 

On the other hand, physicians who are tied to evidence based medicine, and to evidence gathering, may be less receptive.  Without understandable causation, there is no disease.

 

In their (unspoken) minds, patients with complaints that appear to have no physiological basis become, over time, simply “crocks.”

 

 

Background — what is multiple chemical sensitivity?

 

Wikipedia defines multiple chemical sensitivity more plainly than some more allegedly authoritative sources:

 

Multiple chemical sensitivity (MCS) is a chronic medical condition characterized by symptoms that the affected person attributes to low-level chemical exposure.

 

Commonly accused substances include smoke, pesticides, plastics, synthetic fabrics, scented products, petroleum products, and paint fumes.

 

Symptoms are usually vague and non-specific, such as nausea, fatigue, and headaches.

 

MCS is a controversial diagnosis and is not recognized as an organic, chemical-caused illness by the American Medical Association or other authorities.

 

Blinded clinical trials have shown MCS patients react as often and as strongly to placebos, including clean air, as they do to the chemicals they say harm them. This has led some experts to believe MCS symptoms are due to odor hypersensitivity or are mainly psychological.

 

Regardless of the etiology, some people with severe symptoms are disabled as a result, and the fact that these people are disabled is recognized by many government agencies.

 

MCS has been given many different names by proponents, including toxic injury, chemical sensitivity, chemical injury syndrome, 20th century syndrome, environmental illness, sick building syndrome, idiopathic environmental intolerance, and toxicant-induced loss of tolerance.

 

© 2012 Wikipedia, Multiple chemical sensitivity (12 July 2012) (paragraph split)

 

 

What the cited study has to say about “chemical intolerance”

 

The study’s authors immediately bring up the biological complexity that haunts medicine.  And they attack the idea, as I repeatedly do, that one can frame complex medical questions in simplistic black and white terms:

 

 

Chemical intolerance has a prevalence of 2% to 13% in population-based surveys.

 

Symptoms are typically multisystem, that is, affecting cognitive, affective, musculoskeletal, gastrointestinal, genitourinary, and cardiovascular systems.

 

Despite its relatively high prevalence in nonclinical samples, the diagnosis and etiology of chemical intolerance remain controversial and understudied.

 

Skeptics and proponents often frame the debate in a dualistic manner, claiming that chemical intolerance is either completely psychogenic or completely toxicogenic; however, accumulating data suggest that a more nuanced, multifactorial psychobiological process underlies the condition.

 

© 2012 David A. Katerndahl, Iris R. Bell, Raymond F. Palmer, and Claudia S. Miller, Chemical Intolerance in Primary Care Settings: Prevalence, Comorbidity, and Outcomes, Annals of Family Medicine 10(4): 357-365 (July-August 2012) (at first paragraph under Introduction) (paragraph split)

 

 

Not a simple patient population to deal with

 

The problem with multiple chemical sensitivity is that it is (not surprisingly, given its ostensible myriad chemical nature) tied to multiple systemic manifestations, as well as to varying psychiatric accompaniments.  The latter characteristic gives so-inclined providers a handle with which to minimize any physically caused ailments that might exist.

 

The study’s authors explain that chemical intolerance has been associated with asthma, bronchitis, chronic fatigue syndrome, fibromyalgia, hypothyroidism, irritable bowel syndrome, migraine, pneumonia, rhinitis, and systemic lupus erythematosus.  And affected patients often show family histories for similar illnesses and substance abuse.

 

The medical picture is further complicated by psychiatric problems, including (probably among others) panic, anxiety, somatization and mood disorders; major depression; schizophrenia; and hyperactivity.

 

 

If these are not easy patients — how often are their problems actually addressed by primary care practitioners?

 

Population sampled

 

The research team collected self-reported surveys from a sample of 400 patients distributed between the waiting rooms of two primary care clinics in San Antonio, Texas.

 

One group practice treated predominantly lower income Hispanics and the other ministered to their middle class Hispanic and Caucasian equivalents.

 

What the surveys showed

 

Twenty percent of the patients (meaning 81 people) met the study’s criteria for chemical intolerance.  Yet only 24 percent of these had reportedly been diagnosed for the condition.

 

The poorer one was, the more likely one was affected by chemical intolerance.  Only 9 percent of the wealthier patients exhibited criteria for the syndrome — but 25 percent of the poorest group did.

 

In regard to the associated psychiatric symptoms:

 

[P]ersons with high chemical intolerance had markedly elevated odds ratios for possible major depression, generalized anxiety disorder, panic disorder, and alcohol abuse disorder, as well as somatization disorder.

 

[T]he chemically intolerant also had significantly elevated odds of family histories of gastrointestinal disorders, mood disorders, systemic lupus erythematosus, and chemical intolerance.

 

© 2012 David A. Katerndahl, Iris R. Bell, Raymond F. Palmer, and Claudia S. Miller, Chemical Intolerance in Primary Care Settings: Prevalence, Comorbidity, and Outcomes, Annals of Family Medicine 10(4): 357-365 (July-August 2012) (at second paragraph under Discussion – Key Findings) (paragraph split)

 

 

Even with the psychiatric connections, the authors think that physicians should not take the “easy” way out

 

Blaming psychiatric causation alone will not do the diagnostic trick:

 

[T]here is no evidence that treating psychiatric symptoms alone will resolve chemical intolerance.

 

Twin studies of chronic fatigue, a common overlapping diagnosis in chemical intolerance, indicate that psychiatric illness does not fully explain the clinical picture.

 

Previous nonclinical studies showed that psychological distress per se accounts for only a proportion of the variance in chemical intolerance scores.

 

In one study, patients with MCS [multiple chemical sensitivity] pointed to chemical avoidance as the single most helpful intervention. These same patients rated psychotropic medications as least helpful for their condition.

 

Our study and numerous earlier studies have found increased rates of medication intolerances in the chemical intolerance population.

 

© 2012 David A. Katerndahl, Iris R. Bell, Raymond F. Palmer, and Claudia S. Miller, Chemical Intolerance in Primary Care Settings: Prevalence, Comorbidity, and Outcomes, Annals of Family Medicine 10(4): 357-365 (July-August 2012) (at fourth paragraph under Discussion – Key Findings) (paragraph split)

 

 

The study’s concluding point — chemical intolerance is underdiagnosed

 

This is not good because affected people are often seriously affected in all aspects of their lives.

 

 

Caveats

 

The authors point out that self-reports are unreliable.  And the team used an instrument for revealing psychiatric issues that is not actually diagnostic.  (Which is understandable, given that there was no medical professional there to explain and administer it.)

 

Second, the population sample was statistically small and demographically localized.

 

In short, this study is not reliably indicative of anything.

 

 

And an analytical criticism — that probably could not have been overcome

 

My reading of the paper indicates that the researchers themselves seem to founder on the undefined character of the still much disputed “chemical intolerance” diagnosis.

 

In the absence of sound epidemiological or meta-analytical review, one is left thinking that chemical intolerance is a mish-mash of indicators that may or may not be related to identifiable environmental exposures.

 

 

The authors suggest incorporating what might prove to be a valuable screening tool into primary care practice

 

The research team suggests incorporating the self-administered “Quick Environmental Exposure and Sensitivity Inventory” (QEESI) into primary care practice.

 

Incorporation would more reliably detect patients who ultimately display this “mess” of ambiguously connected, but usually hidden, indicators.

 

Note

 

The Inventory consists of 50 questions distributed along 4 scales. The scales measure:

 

(i) symptom severity

 

(ii) sensitivity to inhaled chemicals

 

(iii) sensitivity to foods, medications, and alcoholic beverages

 

and

 

(iv) overall impact on the patient’s quality of life.

 

 

The moral? — a preliminary start to dealing with a difficult syndrome

 

Given (a) biology’s innate complexity and (b) the modern environment’s contamination with unnaturally occurring substances of all kinds, there are certainly a plethora of medical causations of which we are completely unaware.

 

Dismissing patients as “crocks” under difficult-to-read circumstances is probably unwise.

 

Incorporating the “Quick Environmental Exposure and Sensitivity Inventory” into primary care practice may eventually result in collecting enough information to make more definitive progress in treating this kind of human suffering.

 

But future studies of these patients need to deal more definitively with reliable data collection and psychiatric diagnoses.