Clinical ecology. American College of Physicians.

Clinical ecologists propose the existence of a unique illness in which multiple environmental chemicals, foods, drugs, and endogenous C. albicans have a toxic effect on the immune system, thereby adversely affecting other bodily functions. The proposal uses some concepts that superficially resemble those that apply to clinical allergy and toxicology and others that are novel. Review of the clinical ecology literature provides inadequate support for the beliefs and practices of clinical ecology. The existence of an environmental illness as presented in clinical ecology theory must be questioned because of the lack of a clinical definition. Diagnoses and treatments involve procedures of no proven efficacy. Case reports by clinical ecologists and evaluation of these patients by other physicians indicate that this diagnosis is applied most frequently to persons with symptoms of physiologic (somatic) or psychologic dysfunction, or both. Proof of cause-effect relations between environmental factors and symptoms of "environmental illness" is particularly difficult because clinical ecologists implicate such a broad range of agents, including chemicals, foods, hormones, and microorganisms. Most patients are believed to react to multiple environmental substances by any route of exposure, and some are said to be intolerant to the entire environment, the so-called "total allergy syndrome." The principal method of proof cited by clinical ecologists for the existence of "environmental illness" is the symptom-provocation test used in diagnosis of individual cases after the condition is suspected because of a history of symptoms and suspected causes. Published studies on the provocation test employed widely different subject-selection methods and outcome-measurement criteria. All were seriously flawed by the absence of matched patient-control groups, absence or inadequacy of the placebo, and failure to achieve or document randomness of trials. Not surprisingly, therefore, the conclusions from these studies are conflicting. Those studies reporting results of immunologic tests are insufficient to address theories of environmental illness; the number of cases is small and selection criteria are not clear. Enumeration of lymphocyte subsets and quantitation of serum immunoglobulin and complement levels in patients with "environmental illness" have not yielded clear-cut evidence of immunologic abnormality. Clinical ecologists use a treatment program that includes avoidance of environmental chemicals, rotation of foods in the diet, and neutralization of symptoms with injected or sublingual extracts. Except for small-dose oral nystatin, which is used for treatment of patients with the candida hypersensitivity syndrome, drug therapy is intentionally avoided, although some clinical ecologists recommend mineral salts, oxygen, vitamins, minerals, and antioxidants for relief of symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)