Melissa
Kaplan's |
Fungal Hypersensitivity
Pathophysiology, Diagnosis and Therapy
Vincent Marinkovitch, MD, Redwood City CA
Introduction
Molds or fungi are everywhere in nature and their wind borne seeds (spores) make up the majority of the microscopic particles in the air at any time, even when pollen season is at its peak. Their value to the food industry is enormous while their contributions to medicine in the form of antibiotics, vitamins and other drugs is inestimable. But they can cause trouble. Humans in good health can handle typical exposures to molds in the air, in their homes and in their workplaces without much difficulty. However, certain allergy-prone individuals may have symptoms during peak mold levels that include asthma, runny nose, sneezing fits and itchy noses and throats. In the immunologically compromised patient, a single mold spore can initiate a deadly process. Patients on chemotherapy or immune suppression imposed for organ transplantation and those with chronic diseases such as AIDS, recurrent infections, cystic fibrosis and diabetes, are also at risk when exposed to molds at levels that healthy individuals can handle. Exposure to high levels of mold can be a threat to anyone's health--as noticed in certain occupations. These conditions were given name such as farmer's lung, pigeon breeder's disease, malt workers disease, etc. They shared common symptoms, usually involving nose, sinuses and lungs and the consequences were serious, often leading to permanent breathing disorders and death. Over the last 30 years, non-occupational exposures have become recognized as dangerous in homes with moldy air conditioning or humidifiers, homes near composting facilities, and homes with water damage. Exposure to high levels of fungi can be a health threat from inhalation, ingestion or skin contact involving tiny mold spores (invisible to the eye), mold toxins (mycotoxins) or mold bodies themselves. Initial symptoms seem to be the result of inhalation, such as sore throats, hoarseness, cough and nasal congestion. With time, symptoms can progress to include headaches, fatigue, rashes, dizziness, shortness of breath, sinus infections, ear pain, muscle and joist pain, and fever. These symptoms are the result of direct mycotoxin exposure and the effects of an overactive immune system trying desperately to overcome what it perceives to be an overwhelming infection. The immune system generates antibodies to the absorbed mold materials (antigens). These antibodies react with the antigens to form immune complexes, which is all part of the body's normal immune elimination function. When the immune clearance machinery is on overload, the complexes remain in the blood stream causing myriad symptoms, known to clinical immunologists as serum sickness, and appearing to the patient as a severe, unrelenting flu syndrome. Exposure to certain mycotoxins can result in brain damage seen as short-term memory loss, cognitive dysfunction, inability to concentrate and "fuzzy thinking". These changes seem to be reversible, at least in part, but they can take years to resolve. Once the patient has become hypersensitive to the mold in their environment, they have also become overly reactive to all molds in their life including those they breathe elsewhere, those they eat and those that may be colonizing their tissues. Relief of symptoms can only come with a significant reduction in exposure including a mold free diet, avoidance of mold-ridden environments and treatment of mold colonization. Some mold colonizations are well known, such as athlete's foot, vaginal yeast infections, ringworm, excessive dandruff, toenail fungus, etc. But molds are opportunistic and can become established on any tissue that has been previously damaged. This would include the sinuses of a patient who has had a sinus infection, the lungs of a patient with asthma, the nose of a patient with nasal congestion and the gastrointestinal tract of patients who have had chronic indigestion or abdominal discomfort. The patients' healthy, reactive immune system can prevent the mold from invading surrounding tissues and causing infection. However, it is not able to remove the mold from the mucosal or skin surfaces. The colonization continues, the patient continues to form immune complexes with the mold antigens, the overload continues, and the patient grows sicker. Once there is significant colonization, the symptoms continue even after the patient leaves the moldy workplace or home where the high exposures occurred.
Diagnosis Specific IgG antibody levels to molds are helpful in supporting the diagnosis of fungal hypersensitivity. Everyone is exposed to some molds and, therefore, some antibody to mold is found in nearly everyone. But the levels are low. Individuals exposed to heavily moldy environments make great amounts of antibody. In mold hypersensitivity patients it is common to find antibodies to molds in class three or class four categories. Occasionally a patient with significant mold problems will present class two antibody levels. Mold antigens arc highly cross-reactive, which means that an antibody response on exposure to mold A may show significant reactivity on the IgG panel test to mold B as well. Sometimes the molds to which the patient shows highest antibody levels are not identified in an environment survey. This reflects the difficulty of getting the mold growing happily on wet sheet rock to grow on an agar culture dish.
Therapy
Conclusion Appendix: Foods Rich in Fungal Molds This entire document, including the appendix, is available in PDF format.
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