May 2010 Allergies


                                                            ALLERGIES

This article is published by the CMFPD Board of Trustees to assist the residents of Cedar Mountain and all of Kane County to better understand allergies and their effects.                                                                           What does an allergy mean?

An allergy refers to an exaggerated reaction by our immune system in response to bodily contact with certain foreign substances. It is exaggerated because these foreign substances are usually seen by the body as harmless and no response occurs in non- allergic people. Allergic people's bodies recognize the foreign substance and one part of the immune system is turned on. Allergy-producing substances are called "allergens." To understand the language of allergy it is important to remember that allergens are substances that are foreign to the body and can cause an allergic reaction in certain people.  When an allergen comes in contact with the body, it causes the immune system to develop an allergic reaction in persons who are allergic to it. When you inappropriately react to allergens that are normally harmless to other people, you are having an allergic reaction and can be referred to as allergic or atopic. Therefore, people who are prone to allergies are said to be allergic or "atopic."

What causes allergies?

To help answer this question, let's look at a common household example. A few months after the new cat arrives in the house, dad begins to have itchy eyes and episodes of sneezing. One of the

three children develop coughing and wheezing, especially when the cat comes into her bedroom. The mom and the other two children experience no reaction whatsoever to the presence of the cat. How can we explain this?  The immune system is the body's organized defense mechanism against foreign invaders, particularly infections. Its job is to recognize and react to these foreign substances, which are called antigens. Antigens are substances that are capable of causing the production of antibodies. Antigens may or may not lead to an allergic reaction.  The aim of the immune system is to mobilize its forces at the site of invasion and destroy the enemy. One of the ways it does this is to create protective proteins called antibodies that are specifically targeted against particular foreign substances.

 

Where are allergens?

 

We have seen that allergens are special types of antigens that cause allergic reactions. The symptoms and diseases that result depend largely on the route of entry and level of exposure to the allergens. The chemical structure of allergens affects the route of exposure. Airborne pollens, for example, will have little effect on the skin. They are easily inhaled and will thus cause more nasal and lung symptoms and limited skin symptoms. When allergens are swallowed or injected they may travel to other parts of the body and provoke symptoms that are remote from their point of entry.

 

 

 

What are common allergic conditions?

The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Although the various allergic diseases may appear different, they all result from an exaggerated immune response to foreign substances in sensitive people. The following brief descriptions will serve as an overview of common allergic disorders

Allergic rhinitis ("hay fever") is the most common of the allergic diseases and refers to seasonal nasal symptoms that are due to pollens. Year round or perennial allergic rhinitis is usually due to indoor allergens, such as dust mites, animal dander, or molds. It can also be caused by pollens. Symptoms result from the inflammation of the tissues that line the inside of the nose (mucus lining or membranes) after allergens are inhaled. Adjacent areas, such as the ears, sinuses, and throat can also be involved.

Asthma is a breathing problem that results from the inflammation and spasm of the lung's air passages (bronchial tubes). The inflammation causes a narrowing of the air passages, which limits the flow of air into and out of the lungs. Asthma is most often, but not always, related to allergies.

Allergic eyes (allergic conjunctivitis) is inflammation of the tissue layers (membranes) that cover the surface of the eyeball and the undersurface of the eyelid.

Allergic eczema (atopic dermatitis) is an allergic rash that is usually not caused by skin contact with an allergen. This condition is commonly associated with allergic rhinitis or asthma.

Hives (urticaria) are skin reactions that appear as itchy swellings and can occur on any part of the body. Hives can be caused by an allergic reaction, such as to a food or medication, but they also may occur in non-allergic people.

Allergic shock (anaphylaxis or anaphylactic shock) is a life-threatening allergic reaction that can affect a number of organs at the same time. This response typically occurs when the allergen is eaten (for example, foods) or injected (for example, a bee sting).

Shock refers to the insufficient circulation of blood to the body's tissues. Shock is most commonly caused by blood loss or an infection. Allergic shock is caused by dilated and "leaky" blood vessels, which result in a drop in blood pressure.

The CMFPD Board of Trustees hopes you find this information helpful. 

Mike Petullo CEM, Chairman

CMFPD Board of Trustees