Introduction

This article is an introdution to down allergies - one reason why many people are turning to down alternatives. We'll look at what causes allergies in general, and what is thought to be the basis of down allergies. However, we'll withhold final judgement on whether this

basis is solid. For our final verdict, please take a look at our article "Current Medical Thinking on Down Allergies."

The Immune System: the Culprit of Allergies

Our immune system is a fine tunely biological system that is the result of millions of years of evolution. The main function of the immune system is that it must distinguish between biological material that is self, versus material that is non-self. How can the immune cells of our body tell its own cells apart from other cells?

Self and Non-self

It turns out the answer lies in something called "antigen recognition". What is an antigen? It's a piece of foreign protein, not found anywhere in the body. Most organic material has some protein content - for example, down and bird feathers are almost completely made of protein materials. In contrast, down alternatives are synthetic and do not contain protein. How does the body know that it's foreign, versus the many million to billions of forms of other proteins that are native to the body? The answer is not clear yet, and is subject to intense study even now, but one very popular theory is that this process of recognition is entirely learned by the immune system as the organism develops from embryo to adult.

The Wonderful Immune System

In other words, our immune systems start off ignorant. They must discard immune cells that attack the body's own cells, leaving behind only those that recognize foreign proteins. What is most remarkable is that all the immunity which you can ever attain in your adult life is already within you. The remaining step being its potentiation during an infection.

Overactive Immune System

Why does the body react to pollen, peanut butter, down comforters, paint, shell fish and an endless litany of seemingly harmless things? One theory is that because of insufficient exposure to such substances, the immune system of a particular person's body never acclimated to them, and therefore regard minute quantities of such substances in the body to be germ invaders. Upon encountering them, for example pollen proteins entering through the air passageway, the immune cells spring into action and mount a vigorous offense and defense. The consequence of this immune system activation is inflammation of the nasal passageway, production of mucus, incessant sneezing etc.

A Theory of Allergies

In the case of down, there are two common theories. In one, the theory is that the proteins of the waterfowl from which the down is derived causes an allergic reaction. These proteins reside on the surface of the down. In fact, down itself is made up of a protein similar to keratin, which is the basis of human hair. In the other theory, the proteins of dust mites that thrive in down material are the culprit. This theory has it that dust mites secrete small amounts of proteins which some human bodies regard as germ invaders. Therefore, the first theory blames down directly for causing allergies, but the second theory has it that tiny, common dust mites (which are everywhere) are at the root of down allergies. Sometimes, just the thought of tiny critters living in down makes some people want to turn to down alternatives.

Asthma

Up till now we haven't mentioned asthma. Asthma is characterized by a chronic inflammation of the lungs. Inflammation is one of the body's immunity-derived defenses against infectious microorganisms. Therefore, the thinking is that asthma and allergies have some common bases. It's not surprising then that allergens from down or dust mites can give rise to asthma attacks.