In Live Free From Headaches and Allergies we will be exploring the relationship between allergies or, as I prefer to call them, “sensitivities,” and headaches and migraines. I would like to begin our investigation by accurately defining that catch-all concept. A sensitivity, as I use the term in this book, is an abnormal, adverse physical reaction of the body to certain substances, commonly known as allergens (or antigens). While these substances can be either toxic, such as exhaust fumes or other petrochemicals, or non-toxic, such as pollens or food, those who suffer from sensitivities will react to them in quantities that are harmless to most people.
When exposed to allergens, sensitive individuals develop an excess of an antibody called immunoglobulin E (IgE). The IgE antibodies react with allergens to release histamines and other chemicals from cell tissues, producing various sensitivity symptoms. In other words, the immune system mistakenly identifies harmless substances as dangerous invaders and activates an antibody attack to defend the body. The development of an allergy begins with sensitization to the substance on first contact, usually without symptoms. Only upon re-exposure do the previously created antibodies become active and produce symptoms.
Although a person can develop allergies to practically any substance, the most common allergens include pollen, dust, dust mites, animal dander (skin, saliva, hair or fur), feathers, cosmetics, mold, insect venom, certain chemicals, drugs, medicines (especially penicillin), and foods. The most troublesome foods are usually peanuts, other tree nuts, shellfish, milk, egg, wheat, and soy. Allergens may cause a reaction following inhalation, injection, ingestion or contact with the skin. While sensitivity reactions can involve any part of the body, they most frequently affect the nose, chest, skin, and eyes. The rarest and most dangerous type of reaction, called anaphylactic shock, can affect many organs at once, causing a rapid decrease in blood pressure, a rash or hives, breathing difficulties, abdominal pain, a swollen tongue or throat, diarrhea, fainting, asphyxiation, and, all too often, death.
There are between 35 and 50 million people in the United States who suffer from some type of significant allergy. These types of reactions can emerge suddenly at any age without prior warning. Many studies have shown conclusively that parents with sensitivities will tend to have children with sensitivities. However, research suggests that what is inherited is simply the tendency to develop a sensitivity of some kind, not any particular type. Regardless, I have repeatedly seen in my practice that a child’s allergic tendencies are often related to his or her parents, and I have often worked with parents and their children for the same kinds of sensitivities. Since certain people (known as “atopic”) tend to be more susceptible to these types of reactions, once these individuals develop one sensitivity, others will commonly follow.
Part of the difficulty in determining the exact number of allergy sufferers lies in how broadly or narrowly one defines the term. Medical doctors and scientists often maintain a narrow definition, asserting that the only true allergies are those that result from the activation of IgE antibodies. However, millions of people experience symptoms of sensitivity to a food or substance without the antibody reaction. These people can be said to have an intolerance or a hypersensitivity to particular substances. Although the causes may differ, the diagnosis and treatment of sensitivities and intolerance often overlap. As a result, allergy research and information benefits more kinds of people than those with traditional sensitivities alone.
In my clinical work I have found that the measurements and treatments for many allergens, sensitivities and intolerances are exactly the same. Therefore, I use the terms interchangeably. (And for this book, I will use the term sensitivity instead of allergy). For example, many asthmatics also have a sugar intolerance and are sensitive to animal dander. BioSET® testing for these two substances yields identical results, and I work with them in the same way.
Sensitivities can also cause a predisposition to colds and flu by compromising the immune system and lowering resistance. Once the body becomes host to viruses and bacteria, it can be difficult to distinguish a cold from an allergic reaction, especially since they will often occur simultaneously. However, sensitivities don’t generally cause fever, and colds should not linger for more than a week or two, unlike sensitivities, which may refuse to go away.
In this book, I will take the wider view of a sensitivity as any negative or abnormal response in the immune system. For example, I believe there is no such thing as a simple cold. A cold is the response of a challenged immune system, whether it be to a food, a pollen or a virus. Since a virus can also be considered an allergen, I treat a cold like a sensitivity, with excellent results.
From Medscape Allergy & Clinical Immunology
Allergic Diseases — How Big Is the Problem?: An Expert Interview With Mark T. O’Hollaren, MD; Part 1 of 3: Overview of Epidemiology & Prevalence