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Allergy is one of those "consumerized" terms. Most people associate the term "allergy" with a plethora of bothersome and "bad" symptoms that require treatment by purchasing products. When I see minor allergic symptoms, the first thing that crosses my mind is that the patient's immune system is running well and perhaps a little too aggressively. We doctors sometimes get a silent chuckle when someone tells us that they are taking all sorts of herbal "immune-stimulators" to combat the condition. Ragweed sufferers sometimes use chamomile tea to help them sleep, not realizing that chamomile is a cousin of the ragweed. The sedating effect that results is what one would expect with the release of histamines. The effect is comparable to aiming hair-spray at a lit match.
A good knowledge base is the key to self-treatment. Our immune system was designed by the good Lord to protect us. Various components located throughout our body check our status continuously. The basic job of the immune system is to monitor our body for any sign of foreign invasion and quickly react to, contain and destroy the invaders. Foreign invaders can be all sorts of things from plant materials and herbs to viruses and bacteria to pressure and temperature changes. The clear runny nose I get when I venture into the cold is a good example of my system responding normally. The aches, swollen nodes, fever and congestion constitute another sign of the immune battle underway. But a lot of these symptoms such as runny noses and weepy eyes are bothersome to people when they persist. The commonest treatments for these symptoms consist of anti-histamine medications, decongestants and steroidal nasal sprays.
The most deleterious of inappropriate immune responses are called hypersensitivity reactions. Four basic types exist. In Type 1, the foreign substance or antigen that enters the body combines with IgE-antibodies linked to mast cells that release large amounts of histamine. This leads to local engorgement, itchiness and redness. At the extreme, it produces an anaphylactic response in which the airways get engorged and massive swelling results around the face and neck. This is a rare but true emergency that should have attempts made to discover the offending cause. These individuals should also carry special self-injecting syringes full of a reversing agent called epinephrine. It is worthwhile to note that this antidote is short acting and this group of people should seek immediate medical attention.
Type 2 reactions are caused by antibodies reacting with cells within our body to damage the cells. Incompatible blood transfusions are a good example. The end result depends on the amount of exposure.
In Type 3 reactions, the antigens are attacked by our antibodies to form small precipitations in tissues spaces. This typically shows up as a rash, and can cause further inflammation.
Type 4 reactions are delayed hypersensitivity. Special cells within our immune system called T-lymphocytes respond to the foreign antigen by over-vigorously releasing various products which produce a red swollen response at the site where the antigen entered the body.
Some patients end up visiting allergists who conduct allergy testing. The standard protocol employed when the patient has no idea of what might be causing their symptoms is to scratch a whole slew of premixed antigens under the skin. There are virtually hundreds of thousands of different substances that may cause an immune response. Allergists tend to pick the most likely ones such as cat dander, nuts, mites, tree and grass pollen. Oftentimes, tests can be performed to determine if a specific agent such as almonds or penicillin are causing reactions. We now have non-OHIP covered blood tests that can measure changes in antibody response to a limited number of substances such as shellfish, milk and peanuts. One approach to treat a severely overactive immune system is to try to desensitize it by injecting small amounts of the substance under the skin in hopes of dampening future responses.
The important thing to realize is that for most of us allergies are simply a sign that our immune systems are a little over-vigorous. It is the patients that never report any allergic symptoms that I worry about.
Related resources:
● 10 Best Foods to Boost Your Immune System. What you and your family should eat to keep your immune system healthy, by Katherine Lee, About.com Guide.
● Biological Therapies for Cancer: Questions and Answers. "Biological therapy (sometimes called immunotherapy, biotherapy, or biological response modifier therapy) is a relatively new addition to the family of cancer treatments . . . Biological therapies use the body's immune system . . . to fight cancer or to lessen the side effects that may be caused by some cancer treatments. What is the immune system and what are its components?
The immune system is a complex network of cells and organs that work together to defend the body against attacks by 'foreign' or 'non-self' invaders. This network is one of the body's main defenses against infection and disease. The immune system works against diseases, including cancer . . ."
● Allergy & Asthma - Allergies and the Immune System from University of Virginia Health System. Allergies are disorders of the immune system. Most allergic reactions are a result of an immune system that responds to a false alarm.
● About the Immune System & Allergies. eHow Video (2:33 min.) by Dr. David Hill.
● What is an allergy? from About.com.
● Allergies and Asthma. WebMD videos.
● How Allergies Work from HowStuffWorks.
● Immune System from National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH). The immune system is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders. These are primarily microbes—tiny organisms such as bacteria, parasites, and fungi that can cause infections.
● Allergy / Allergies from MedicineNet. What does an allergy mean? What causes allergies? Who is at risk and why? What are common allergic conditions and their symptoms and signs? .
● Allergies and Immune System
Causes & Types of Allergies from Discovery Health.