Environmental Medicine deals with chronic health problems linked with various environmental factors in our air, food and water. These factors can be associated in some people with multiple complaints involving several different organ systems. Symptoms vary in number and severity depending on the frequency and amount of exposure to the problem factors. Individuals who chronically note multi-organ symptoms when exposed to low levels of multiple chemically-unrelated substances and whose symptoms improve or resolve when the incitants are removed, are said to have environmental sensitivities or environmental hypersensitivity disorder or multiple chemical sensitivity (Multiple Chemical Sensitivity: A 1999 Consensus, Archives of Environmental Health, May/June 1999 [Vol . 54 (No. 3), 147-149).

One of the body systems most commonly affected by environmental sensitivities is the central nervous system with complaints of headache, fatigue, poor concentration, decreased short-term memory, spaciness, distractibility, mood swings, irritability, and/or depression. Other systems may be involved such as the gastrointestinal system with digestive problems such as gas, bloating, constipation or diarrhea, the musculoskeletal system with muscle and joint pain, the genitourinary system with vaginal infections and irritable bladder, the upper respiratory system with ear, nose and throat congestion, the lower respiratory system with asthma, and the skin with hives, eczema, etc. Symptoms may be prolonged, even after removal from the inciting exposures, and can sometimes be disabling. The University of Toronto has completed a large survey, which included Dr. Krop’s patients, in order to study these symptoms further and their relationship to various commonly encountered substances.

In the last 40 years our generation has had more exposure to chemical pollutants than any previous generation. They are in our food, water, soil, and air. In spite of ever growing outdoor pollution, which also creates climate changes, our greatest chemical pollutant exposure on a daily basis is in indoor air. It has been postulated that chronic chemical exposures that overwhelm body defence mechanisms could be contributing to increasing incidence of allergies, sensitivities and toxicity which can manifest as sick building syndrome or chemical sensitivity.

Most people suffering from these disorders have usually had multiple investigations from a variety of physicians. Contemporary science has not yet discovered specific objective biological markers.

Because of the variety of complaints, and the absence of a reliable objective biological marker (test) for Environmental Sensitivity Disorder, many people are told that they must be suffering from psychological "stress". The body responds to any perceived threat with a stress response (H. Selye, The General Adaptation Syndrome and the Diseases of Adaptation, Journal of Allergy (1946) 17: 231-247,289-323,358-398). This stress response can be induced by exposure to toxins, irritants, allergens, infectious organisms, radiation, temperature extremes, hormonal imbalances, difficult life events or relationships, nutritional deficiencies, sleep disturbances, etc. Any combination of such stressors is thought to contribute to the total body burden or load of stress affecting a person.

We encounter many minor stresses in our daily lives, which the body usually adapts to and handles well. However, if the stress load is large enough and goes on for a long enough period of time, our capacity to adapt may become overwhelmed. The threshold for tolerating stress may be lowered and minor stresses may start to give aggravated physiological responses resulting in symptoms. We are now MALADAPTED. Systems that are always affected by chronic stress include the neurological, endocrine and immune systems. Physiological chemicals known as neurotransmitters, hormones and mediators are released by cells to communicate with appropriate receptors on other cells in any part of the body. Therefore, stress from multiple sources can initiate or exaggerate symptoms related to any organ. The state of health of a patient is an expression of the interplay of the above factors and the patient’s own genetic endowment, which creates his/her unique biological individuality (i.e. the same stressors can produce different symptoms in different persons).

Environmental Medicine focuses on four categories of environmental factors that may affect health. An individual may be simultaneously exposed to all four categories increasing his/her total body burden or stress load to a level beyond his or her capacity to adapt. In this office we attempt to evaluate the significance of each of the following factors for each patient.

Some of the tests mentioned below (3, 4, 6) are considered by the College of Physicians and Surgeons of Ontario to have no scientific basis and are considered to have no proven value either as a test or as a therapy. Some of these tests, however, are considered as standard practice by the American Academy of Environmental Medicine. Dr. Krop has found them to be helpful, informative and very useful in managing the state of health of patients with chronic, degenerative, complex medical problems.

To identify possible allergies and sensitivities to inhalants, foods, chemicals and toxins, in this office we choose from the following 6 types of tests:

1. Prick test: Used by allergists for almost 100 years, drops of the diluted substances to be tested (antigens) are placed on the skin of the forearm or back. The skin is then pricked through the drops and, after 20 minutes, any redness or swelling of the skin around the marks is recorded. Such a response is a useful screening test because it indicates the body has produced immunoglobulin E (IgE) antibodies to the substance. If the positive test is to a natural inhalant antigen suspected of causing symptoms from the medical history, trials of environmental control and possibly immunotherapy (using stock concentrations of the provoking antigens) are warranted, along with medications to relieve the symptoms. A limited number of these tests are covered by OHIP. Evidence is Level II. Major disadvantages of this test are that it does not identify responses by pathways other than IgE, including many food intolerances and it also does not indicate individualized physiological responses to antigens and the level of the patient’s response to them. This test is covered by OHIP.

2. Serial Dilution Endpoint Titration (SDEPT): A precise amount of a weak dilution of one antigen is injected into the skin (intradermally) and, after 10 minutes, any skin reaction as well as any signs or symptoms are recorded. If there is no response, the test continues by injecting other stronger dilutions of the same antigen until the skin first shows redness and swelling (wheal). This dilution may then be used as a treatment dose if formulating individualized immunotherapy. This test was developed as an improvement to the prick test, and evidence is Level I. Since only one antigen is tested at a time, and testing begins with a weak dilution, SDEPT is safe, but time-consuming. This test is not covered by OHIP.

3. Optimum Tolerated Dose Determination (Provocation/Neutralization or P/N): A precise amount in drop form of a strong dilution (concentrate) of one food or chemical extract is placed under the tongue (sublingually) where it will be rapidly absorbed into the bloodstream. If signs and symptoms occur within 5 minutes, further weaker dilutions of the same antigen are sequentially placed sublingually until signs or symptoms are no longer provoked. This dilution may then be used as a treatment dose if formulating individualized immunotherapy. This test may also be done intradermally. Evidence is Level II. This test is not covered by OHIP.

4. Electrodermal (ED) testing: A vial containing the substance to be tested is placed on the instrument test plate (Dr. Krop uses the Vega machine). Changes in the electrical skin resistance of acupuncture points on the toes are recorded in the instrument’s galvanometer. This is a benign and non-invasive test, but has Level V evidence. Dr. Krop has published three small trials. This test is not covered by OHIP.

5. Elimination and Re-challenge Tests: If one is continually being exposed to small amounts of a substance to which one has been sensitized, the body adapts as best it can, and so no symptoms may appear when the usual daily dose is encountered at the usual intervals. It is only when the body is de-adapted by avoidance of provocative exposures that the food or chemical sensitivity may be unmasked with symptoms being provoked on re-exposure. Randolph developed a special hospital unit with very pure air where he fasted chronically ill individuals on spring water until their symptoms were relieved, and then challenged them with individual foods and chemicals (T.G. Randolph, Ecologic orientation in medicine: comprehensive environmental control in diagnosis and therapy. Annals of Allergy 1965; 23:7-22). When neither the patient nor the doctor know what is being challenged, it is called a double blind study (both the patient and doctor are "blinded"). To ensure the patient doesn’t taste the food, it has been placed in an opaque syringe and fed to the patient via a nasogastric (nose to stomach) tube. It is thought that chemical sensitivities can be tested most accurately and objectively by placing the patient in a specially constructed booth under controlled environmental conditions, after de-adaptation, and by challenging the patient double blindly with individual chemicals at doses below the odour threshold (N. Ashford, C. Miller, Chemical Exposures, Low Levels, High Stakes, 2^nd Edition, 1998, Van Nostrand Reinhold). Evidence is Level III.

Obviously, these type of elimination and re-challenge tests are impractical in a medical office. However, Dr. Krop tries to use the principles of these tests wherever possible. His office has been designed to provide as clean an environment as possible for testing. At the conclusion of single blind screening with prick, SDET, P/N, or ED testing, you, the patient, will be informed about what foods, natural inhalants, or chemicals were tested, Dr. Krop may ask that you keep a diary of your food intake, activities, and symptoms while avoiding suspected substances. He or his staff may then instruct you how to do re-exposure challenges and to record your responses. He will go over your diary with you, and then advise you about avoidance or treatment techniques.

6. Blood, Hair, Saliva, Stool and Urine Tests : In addition to the common blood and urine tests covered by OHIP, in this office we offer blood and urine tests for toxic chemicals; blood as well as hair analysis tests for heavy metals; blood antibody levels for candida-related complex; blood levels of amino acids; blood and urine tests after challenges with substances to test Phases I and II of liver detoxifying function; blood, urine, and saliva measurements to determine the body’s biological terrain; digestive stool analysis, etc. Some of these tests are relatively new and the Levels of Evidence for them range from Level II to V. These tests are not covered by OHIP.

Dr. Krop determines the substances used in all these tests after taking a detailed and comprehensive environmental and nutritional history. This screening provides information for a trial of therapy (environmental controls, elimination and/or four-day rotation diet and/or desensitization shots or drops), which is then used to help establish or rule out the diagnosis of environmental sensitivity or toxicity. Foods or any other substances to which a patient has known anaphylactic shock reactions are never tested and must be avoided in all forms and circumstances. Patients with anaphylaxis are instructed to carry an Epipen at all times.

Occasionally, symptoms provoked during testing may not be completely relieved by giving weaker dilutions of the test substances. Oxygen and oral bicarbonate salts are used to help clear remaining symptoms. Almost any symptoms can be provoked during testing, most often the symptoms which brought you to this office. On rare occasions a more serious allergic reaction can take place which needs to be treated with an antihistamine as well. On very rare occasions a potentially fatal anaphylactic reaction can take place and your blood pressure may drop, requiring an injection of adrenaline, intravenous medication, use of oxygen, etc. This office is well equipped to handle such a problem, should it occur.

Once the underlying contributors to your health problems are uncovered, treatment is as direct as possible to remove or minimize these factors.

Treatment consists of education about the usual course of illness (Level III evidence), environmental controls (Level I), dietary changes (elimination and four-day rotation diet) (Level II), nutritional supplements (oral, Level II and intravenous, Level IV), correction of hormonal or metabolic deficiencies or imbalances (Level III), heavy metal detoxification and chelation (Level II), immunotherapy (injectable, Level III and/or sublingual, Level III), and prescribed medications or surgery where indicated.

Some substances cannot be eliminated or avoided. For example, if you are sensitive to pollens, you can only partially avoid them in season by staying indoors with the windows closed. Molds and house dust can be impossible to avoid as they are present year round. You may need allergy injections to decrease reactions and, in the long run, to desensitize you. These injections are not formulated from the same dilutions of stock extracts for everyone, but are individually formulated according to your level of sensitivity to each of the component antigens. The desensitization for foods, natural inhalants and chemicals can be achieved sublingually or by subcutaneous (under the skin) injections (Level IV). The newest desensitization technique is Enzyme-Potentiated Desensitization (EPD) therapy, which combines minute doses of multiple, commonly encountered antigens in one injection taken every few months, and was originated by Dr. Leonard McEwen in England. (Level III). Dr. Krop is participating in a prospective study with Dr. McEwen tracking the responses of patients choosing EPD. Please see the separate information booklet on EPD if you are contemplating this therapy.