The Origin of Allergic Reactions

August 12, 2009 by  
Filed under Allergies

An allergic reaction results basically by the interaction of two things – the allergy causing agent, which is known as allergen, and the human being who is the allergy victim. Lots of things in nature are potential allergens, based upon the human immune system’s response to it.

Every cell in the human body has a unique trade mark to it. Body’ immune system recognizes that trade mark. It gets suspicious of any particle like a bacteria or virus in the body that does not carry that trade mark and considers it an unwelcome interference that has to be removed. It is because of this propensity that body tends to reject a transplanted organ. Allergy is a miniature form of this organ rejection.

To attack an object that it recognizes as a foreign body, white blood cells travel towards that object. In the case of an allergy attack, what the white blood cells recognize as enemy are generally certain proteins. Proteins in certain foods or pollen grains are recognized as foreign objects by the immune system of some people. Their white blood cells release enzymes and histamines to cover the enemy object, starting an allergic reaction.

While the basic principle of identifying a foreign object is the same in everybody’s body, in the case of those prone to allergies, the immune system overreacts. The system produces too much of histamines and the like. This is what translates in human beings as allergy symptoms like itching, swelling, or watery eyes.

While this allergy response, or reaction of the immune system, can vary from individual to individual, it can also vary in the same individual over a period of time. For example, consider the case of an individual who is constantly exposed to dust. In the normal course of events, he may not show any allergy symptoms, because the harmful part of it is generally filtered out by the body. But the dust mites in the dust may leave its proteins in his system so that after continuous exposure, he may become extra sensitive to it, leading to stronger allergic reactions.

Genes definitely seem to have some role in making a person prone to allergy because it is often found to be an inherited trait. However, there could be environmental factors also that play a catalytic role in inducing allergic reactions. A breastfed baby, for example, is seen to be less prone to allergy even in a family more prone to allergy.

A new born infant does not generally have a strong immune system. It gets the necessary antibodies from its mother through breast milk and colostrum (the milk produced by the mother for a few days after giving birth).

Since babies produce very little stomach acid, the antibody proteins are not destroyed by their stomach acid. So the proteins, and peptide hormones like prolactin absorbed through breast milk, survive in the infant’s system. Further, proteins that help the immune system are glycosylated. That too protects them from breaking down. All these make babies less prone to allergy.

It needs a lot more study on the functioning of the immune system to be able to pinpoint what exactly triggers allergic reactions and how to control allergy symptoms.