What is an allergy? Allergy facts

Allergy facts

• Allergy involves an exaggerated response of the immune system, often to common substances such as foods or pollen.
• The immune system is a complex system that normally defends the body against foreign invaders, such as bacteria and viruses, while also surveying for abnormal changes in an individual’s own cells, such as cancer.
• Allergens are substances that are foreign to the body and that cause an allergic reaction.
• IgE is the allergic antibody.
• Although many individuals outgrow allergies over time, allergies can also develop at any age, including during adulthood.
• While the environment plays a role in the development of allergy, there is a greater risk of developing allergic conditions if a person has a family history of allergy, especially in parents or siblings.

Allergy overview

This is a review regarding how the allergic response of the immune system occurs and why certain people become allergic. The most common allergic diseases are described, including allergic rhinitis (nasal allergies), allergic conjunctivitis (eye allergies), allergic asthma, urticaria (hives), and food allergies.

What is an allergy?

An allergy refers to an exaggerated reaction by the immune system in response to exposure to certain foreign substances. The response is exaggerated because these foreign substances are normally seen by the body as harmless in nonallergic individuals and do not cause a response in them. In allergic individuals, the body recognizes the foreign substance, and the allergic part of the immune system generates a response.
Allergy-producing substances are called "allergens." Examples of allergens include pollens, dust mites, molds, animal proteins, foods, and medications. When an allergic individual comes in contact with an allergen, the immune system mounts a response through the IgE antibody. People who are prone to allergies are said to be allergic or "atopic."

What Causes Allergies?

That sniffling, that sinus pressure, and all that sneezing must be caused by something. The big question is: what?
Unfortunately for allergy sufferers, there can be many causes. These are known as “allergens,” and they can cause your body’s immune system to over-react. Allergens include

• ragweed,
• grass,
• pet dander,
• dust mites, and
• mold.

Although these things are usually harmless, people who have developed allergies to them will find they cause a lot of misery, and sometimes lead to serious health risks. In America, more than 50 million people suffer from them each year. That adds up to an annual cost of more than $18 billion.
In the following slides, learn more about nasal allergies, like who’s at risk, why allergic reactions occur, how they affect your health, and how they can be treated.

Allergens: The Invaders

Your immune system targets and protects you against health threats like viruses and harmful bacteria. In this photo you can see some bacteria (pink).

But if you're allergic to pet dander, for example, your immune system sees them as a threat, just like a harmful virus. So when you're exposed to pet dander, your immune system is ready to fight.

When your immune system reacts to an allergen, the effects on your health can range widely. Some immune reactions are mild, like the nasal problems being discussed here. However some reactions can be life-threatening, as in the case of anaphylaxis, also known as anaphylactic shock.

Anaphylaxis

While some allergic reactions are mild and may be restricted to certain parts of the body, anaphylaxis is severe and affects the health of the whole body. Anaphylaxis comes on quickly, and it can be deadly. It causes tissues to release histamine, along with other substances that cause breathing problems and other symptoms like

• abdominal pain,
• dizziness,
• difficulty swallowing,
• facial swelling, and unconsciousness
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Asthma

Like anaphylaxis, asthma can be life-threatening in severe cases. Asthma often causes your breathing passages to become inflamed and tight, causing symptoms such as wheezing, cough, and shortness of breath.

The relationship between asthma and allergies is complicated. The two conditions seem to be related, as many people with asthma are also prone to allergic reactions.

What Are Your Allergy Triggers?

It’s easy to come in contact with allergens because they’re potentially everywhere, riding through the air we breathe both indoors and outdoors. Chasing after dust bunnies, playing with your pet, or just walking out the door during certain seasons of the year can set off your symptoms. An allergic reaction is set in motion by either

• touching,
• swallowing, or
• inhaling

an allergen. Below we discuss two of the most common triggers.

Dust Mites

Dust mites are among the most common allergy triggers. These microscopic creatures live on dead human skin flakes found in household dust. They love warm, humid places, and even immaculate homes have them in the carpet, curtains, upholstered furniture, and stuffed animals.

Pollen

Pollen is the reason for seasonal allergies. It is carried in the air and helps grasses, weeds, and trees fertilize and spread. Pollen prevalence can be predicted by the season, but pollen counts vary from year to year, and from region to region. By checking local weather forecasts, you can easily discover the current pollen count.

Your Body’s Reaction to Allergens

Once an allergen enters your body, your immune system reacts and starts making antibodies. Antibodies can be so specific that they only target certain types of pollen, for example. When the immune system detects an allergen, more of the proper antibodies are produced.

The antibodies set to work searching for the offending allergen and eventually get rid of them.

Releasing Histamines

When antibodies find an allergen, they begin to alert mast cells. Mast cells are blood cells that release more chemicals, including histamine. Histamine causes inflammation, meaning small blood vessels become leaky. This causes fluid to escape, which leads to

• runny noses,
• nasal swelling, and
• congestion.

Are Allergic Reactions Hereditary?

Like many other issues related to your health, whether or not you become allergic tends to be determined by your parents. When one parent is prone to allergic reactions, a child’s chances of getting them stands at about 50%, and when both parents are affected, the child’s risk goes up to 80%.
With that said, anyone can experience allergic reactions, regardless of race, age, gender, or any other status. Children tend to be affected more than adults, however.
Whether someone develops an allergic reaction can depend on how much they’ve been exposed to a particular trigger. Some allergies can take years to develop.

Allergy Prevention

Because there’s no way to completely cure allergies, the best way to find relief and restore your health is to find ways to prevent allergic reactions. Here are some tips:

• Avoid allergy triggers when you can.
• Check pollen or mold reports before going outside.
• If levels are high, think about wearing a face mask.
• During allergy season, shower before going to bed so you don't go to sleep with pollen in your hair.
• Keep windows closed and run the air conditioner.
• Vacuum twice a week to cut down on allergens.

Nasal Sprays and Other Medicine

Over-the-counter medicine can help control symptoms of allergic reactions. Such medicines include antihistamines and

decongestants. These medications may be administered in different forms, such as pills or capsules, liquids, eye drops, or nasal sprays.
Talk with your pharmacist or doctor about which medicine might be best for you.

When to Call an Allergist

Allergies can be notoriously difficult to identify. If you can’t say for sure what’s causing them, or if they’re severe, an allergist can help. Allergists and immunologists are medically trained to identify and treat your symptoms.

The doctor will take your medical history and may perform tests. These tests expose you to possible allergens in a systematic way to see which allergens may cause a reaction. Depending on your allergic symptoms, your doctor may suggest prescription medications or allergy shots.
SOURCE :MedicineNet , AAFA.org