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Biomedical subjects

A I Terr

Publications and source records attributed to A I Terr.

At least 19 recordsLinked to original sources

Multiple chemical sensitivity syndrome: a clinical perspective. I. Case definition, theories of pathogenesis, and research needs.

Multiple chemical sensitivity syndrome (MCS) does not appear to fit established principles of toxicology. Yet social, political, and economic forces are demanding that MCS be defined medically, even though to date scientific studies have not identified pathogenic mechanisms for the condition or any objective diagnostic criteria. Consequently, a working definition of MCS can rely only on an individual's subjective symptoms of distress and attribution to environmental exposures rather than currently measurable objective evidence of disease. Nevertheless, patients labeled with MCS are clearly distressed and many are functionally disabled. In this review, four theories of causation are explored: (1) MCS is a purely biologic/physical or psychophysiologic reaction to low-level chemical exposures. (2) MCS symptoms may be elicited by low-level environmental chemical exposures, but the sensitivity is initiated by psychologic stress. (3) MCS is a misdiagnosis and chemical exposure is not the cause. The symptoms may be due to misdiagnosed physical or psychologic illness. (4) MCS is an illness belief system manifest by culturally shaped illness behavior. Areas for further research regarding the etiologies of MCS are suggested. Recognizing that the cause of the syndrome may be multifactorial, strategies are proposed for clinical evaluation and management in Part II of this manuscript using a biopsychosocial model of illness.

Humans

Multiple chemical sensitivity syndrome: a clinical perspective. II. Evaluation, diagnostic testing, treatment, and social considerations.

Multiple chemical sensitivity syndrome (MCS) does not appear to fit established principles of toxicology. Social, political, and economic forces are demanding that MCS be defined medically, even though scientific studies have failed as yet to identify pathogenic mechanisms for the condition or any objective diagnostic criteria. Consequently, a working definition of MCS can only rely on a person's subjective symptoms of distress and attribution to environmental exposures rather than currently measurable objective evidence of disease. Nevertheless, patients labeled with MCS are clearly distressed and many are functionally disabled. Without reconciling the different theories of etiology of MCS discussed in Part I of this report, and recognizing that the cause of the syndrome may be multifactorial, strategies are proposed for clinical evaluation and management of patients with MCS using a biopsychosocial model of illness. The social implications of this illness are also discussed.

Health Policy

Guidelines for the clinical evaluation of occupational asthma due to high molecular weight (HMW) allergens. Report of the Subcommittee on the Clinical Evaluation of Occupational Asthma due to HMW Allergens.

Sensitization to HMW allergens is a relatively common immunopathogenic factor in occupational asthma. The mechanism of sensitization is an IgE-mediated, type I reaction. High molecular weight allergen refers to proteins and polymers of organic compounds over 5 kd and usually in the 20 to 50 kd range. In most cases diagnosis requires: 1. A high index of suspicion of job-related asthma. 2. Exposure to HMW compounds and clinical findings associated with such an exposure. 3. Confirmation of sensitization by appropriate in vitro or in vivo tests. 4. Confirmation of a pathogenic role by physiologic measurements in either a natural setting or during laboratory-controlled challenges.

Allergens

Clinical ecology in the workplace.

The field of clinical ecology is based on a putative diagnosis of "environmental illness," applied to persons who have multiple symptoms and are believed to be sensitive to numerous items in the environment. Increasingly this diagnosis is being used by workers for an occupational disability claim. Medical records of 90 workers claiming work-related "environmental illness" were reviewed. The majority were women. They worked in a variety of occupations with no unifying feature of the type of work or the claimed causative exposure. Symptoms were multiple and unaccompanied by objective clinical findings. Careful review of medical records showed that most had their symptoms before the claimed occupational exposure. Examining physicians who were not clinical ecologists invariably arrived at other diagnoses, usually psychiatric. This retrospective review lends no support to the clinical ecology concept of "environmental illness."

Adult

In vitro tests for immediate hypersensitivity.

In vitro measurement of IgE antibodies in serum has an established role in the study of allergic disease, but the place of in vitro tests in routine diagnosis is not well established. They are particularly helpful in confirming new allergens in the workplace and in situations where skin testing is potentially dangerous or technically not feasible. The basic procedure is the radioallergosorbent test (RAST). Each modification has its peculiar advantages and disadvantages. A clinician depending upon in vitro tests for diagnosis must be aware of the technical problems, the inherent limitation in sensitivity in comparison to skin testing, and above all, the fact that in vitro tests detect the presence of an IgE antibody in serum but give no direct information about its pathogenetic role in an individual patient.

Anaphylaxis

Clinical ecology.

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Adaptation, Physiological

Effect of total lymphoid irradiation on IgE antibody responses in rheumatoid arthritis and systemic lupus erythematosus.

Thirteen patients with rheumatoid arthritis and four patients with systemic lupus erythematosus and nephritis were treated with total lymphoid irradiation because of severe disease refractory to other forms of treatment. Serum samples before and after irradiation were tested for changes in total serum IgE and for changes in specific IgE antibodies to ryegrass pollen, dust mite, cat dander, and Alternaria. There were no statistically significant changes in total or specific IgE from lymphoid irradiation in these patients. The therapy caused a significant decrease in circulating total lymphocyte and Leu-3 (helper/inducer) T-lymphocyte counts. Therefore, reduction in circulating levels of helper/inducer T cells does not appear to influence preexisting levels of IgE antibodies.

Adult

Environmental illness. A clinical review of 50 cases.

A review of 50 patients with a clinical ecology diagnosis of environmentally induced illness is reported. Histories were extremely heterogeneous. Eight patients had no symptoms or disease, 11 had symptoms caused by preexisting nonenvironmental disease, and 31 had multiple subjective symptoms. No consistent physical findings or laboratory abnormalities were found. Serum levels of immunoglobulins and complement, and circulating lymphocyte, B-cell, T-cell, and T-cell subset counts were not significantly abnormal. The diagnostic provocation-neutralization procedure, environmental restrictions, and dietary advice of clinical ecology produced further symptoms and fear of environmental and food contaminants. The patients with chronic multisystem complaints had characteristic symptoms of psychosomatic illness, but this study does not support the clinical ecology theory that psychosomatic illness may be an expression of food and chemical sensitivities induced by the toxic effect of environmental chemicals on the immune system.

Adult

Anaphylaxis.

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Anaphylaxis

The cytotoxic test.

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Cytotoxicity Tests, Immunologic