We need to know that at
the core of our immune system is the ability of our body to differentiate
between self and non-self. An allergy
occurs when your body’s immune system sees a certain substance as harmful
though it might be a harmless substance such as pollen or dust. The immune system reacts by causing an
allergic reaction. Substances that cause
allergic reactions are called allergens.
This attack by the immune system on the harmless substance is called
allergy. For example, some people have
dust allergy while some have pollen allergy.
Before we go further we need to know what are antibody. Antibody is a blood protein produced in
response to and counteracting a specific antigen (a toxin or other foreign
substances). During production by the
immune system, in cases where the antibodies react to non-threatening proteins,
such as those found in pollens, then allergy results. In people with such allergies, what happens is
that the immune system mistakenly identifies the particular allergen as an
invader and begins to create antibodies against it. These antibodies, called the IgE, attach
themselves to mast cells (mast cells are "master regulators" of the immune system. They
come from bone marrow and go into all tissues of the body. Each mast cell contains secretory granules
(storage sacs), each containing powerful biologically active molecules called
mediators), which are abundant
under the surface of the skin and in the nose, eyes, lungs and gastrointestinal
tract. When the allergen is encountered,
the IgE antibodies grab it, triggering the mast cells to release powerful
chemicals including histamine. This
causes the allergic reaction. A reaction
often occurs within minutes or up to a few hours after contact and may lead to
many different symptoms.
In a sense, allergy can
be thought of as one extreme on a spectrum and autoimmune disorders the other
extreme on a spectrum. Health is thus a
balance between the two where the immune response is always appropriate and
controlled. If anything goes out of sync
then we have one illness after another, a never ending cycle of illness.
