How Allergies Work
My son, Manny, has a curious mind and asks questions incessantly.
Last night he was captivated by one of his favorite shows, How It’s Made, which was explaining the process of making hot water heaters. Life as Manny’s father can be challenging, struggling to provide answers to his questions. I must say, however, that I respect this attribute. Knowledge brings understanding and, sometimes, solutions - especially when dealing with pesky medical issues like allergies.
What IS Allergy?
Simply put, allergy is the body’s immune system reacting to a substance in the environment that is normally harmless. This reaction is immediate. In fact, allergy is one of four types of "immediate type" hypersensitivity reaction. While volumes have been written on this “reaction,” it is a rather straight-forward sequence of events. Whether the allergy is to a food, pollen, or medication, the basics of the reaction are the same in the body.
My son might ask, “But how do you get allergic to something?” There are three basic risk factors which make you more likely to develop an allergy:repeated exposure, heredity, and race.
The Science of Allergy: 5 Steps to Allergy Development
When the conditions are right, a substance becomes an allergen through stimulation of the immune system.
- Exposure to an Allergenic Substance. For unknown reasons, an encounter with a substance (perhaps the first time or the ten thousandth time) starts the sequence. It's important to note that it does require an exposure. Nobody is allergic to penicillin, for instance, the first time they take it.
- Antibody Production. If allergy is to develop, a special white blood cell, (the cells that make up the immune system in the blood) called an antigen presenting cell, grabs another white blood cell called a T-lymphocyte to produce a chemical to stimulate yet another white blood cell to produce a specialized particle called an antibody.
- Antibody Bonds to Mast Cell. This antibody plants itself on another specialized white blood cell, called a mast cell, and is now ready for exposure should the allergen intrude again. The antibody is unique for the allergen, like a key recognizing its one companion lock.
- Re-exposure to the Allergenic Substance. In allergy, the allergen exposes itself to the body (nose, blood, mouth, gut, eyeball, etc) as a lock approaching millions of duplicate keys. When this union occurs with the antibody keys on the mast cell, a process on the mast cell is unlocked.
- Histamine Reaction. These mast cells contain countless spherical enclosures of a substance called histamine. Allergen with antibody produces signals that cause the histamine capsules to migrate toward the outside wall of the cell and get expelled into the body tissue and blood. Histamine, in turn, brings about the symptoms of allergy. This response is quite varied, ranging from isolated bowel issues, to hay fever like symptoms, to life threatening anaphylaxis (airway constriction and shock).
Understanding allergy helps to develop therapy for the problem. Remedies, be they homeopathic, pharmaceutical, or otherwise, aim at interrupting the signals or treating the results of histamine release in the body.
Of all the diseases I deal with, I fear and respect allergy the most. The closest I have been to having a patient die in my office has been due to allergy. Allergy can take a nice meal and turn it into a medical emergency. Allergy can take one wrong step on a bee hive and turn it into a last step. I check medication allergies before I prescribe or inject anything into a patient.
If you have a serious allergy, I strongly encourage you to get a medic alert bracelet and carry your epinephrine pen (this hormone, otherwise known as adrenaline, blocks the effects of anaphylaxis) at all times.
Photo Credit: Trumanlo