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Double-blind provocation chamber challenges in 20 patients presenting with "multiple chemical sensitivity"
H Staudenmayer1, J C Selner, M P Buhr
1Allergy Respiratory Institute of Colorado, Denver 80222.
Regulatory Toxicology and Pharmacology : RTP
|August 1, 1993
Summary
This study investigated chemical sensitivity in patients with multiple symptoms. Double-blind challenges found no reliable evidence of chemical hypersensitivity, suggesting psychological factors may play a role.
Area of Science:
- Environmental Health
- Clinical Psychology
- Toxicology
Background:
- Patients presenting with polysomatic symptoms often attribute them to chemical hypersensitivity.
- Previous evaluations using clinical ecology have diagnosed "multiple chemical sensitivity" (MCS).
- Distinguishing verifiable chemical sensitivity from psychological disorders is crucial for accurate diagnosis and treatment.
Purpose of the Study:
- To assess the validity of chemical hypersensitivity in patients referred for evaluation of symptoms attributed to chemical exposure.
- To differentiate between genuine reactions to chemicals and psychological influences.
- To evaluate the efficacy of diagnostic methods for "multiple chemical sensitivity".
Main Methods:
- A clinical algorithm was employed to evaluate patients.
- Twenty patients underwent double-blind provocation challenges in an environmental chamber.
- Chemical and clean air (placebo) challenges were administered using an olfactory masker.
Main Results:
- Group analyses of 145 challenges showed low sensitivity (33.3%), specificity (64.7%), and efficiency (52.4%) for detecting chemical sensitivity.
- No individual patient demonstrated a consistent, reliable response pattern across repeated challenges.
- The study failed to establish a verifiable link between low-level chemical exposure and reported symptoms in this cohort.
Conclusions:
- The findings challenge the diagnostic criteria for "multiple chemical sensitivity" based on subjective symptom reporting during provocation tests.
- The study suggests that psychological factors may be more significant than previously assumed in patients reporting chemical hypersensitivity.
- Future research should incorporate neurophysiologic and neurobehavioral measures to refine assessment methodologies for complex somatic symptom disorders.