What is Allergy? Why Do You Get Allergy? Know its causes

Allergy can be terrible. You get those pink colored raised itching rashes on your skin, a running or blocked nose, watery eyes, swollen lips and even shortness of breath.

Allergy is basically a abnormal hypersensitive reaction or a disorder of your body to a substance or substances (allergens).  It is a repulsion or an aversion, the body shows to these allergens by directing its defensive network against them.

It is as though your body hates that substance (allergen) and therefore loathes it and shows it by producing allergy reaction.

Allergies are one of the most common chronic conditions worldwide. The reason for allergy being  chronic is that person gets repeatedly exposed to the allergen.

Being chronic, makes this health condition even more damning. In addition, it is not possible to forecast or predict if you are going to be a victim of which allergen.

An allergic reaction can take a few seconds, a few minutes or a few hours or rarely as long as a day to develop.  It depends on the type of the substance that has caused the allergy and how sensitive your body is to it.

Many allergic reactions are mild while some may be severe.

Some reactions may be confined to a part of the body while some may affect the entire body.

In addition, these allergy problems can last for one to two days and can even recur.  To make it worse, many times, the root cause of the allergy on the body cannot be identified.

For the same reason, why some people develop allergy and others do not, cannot be explained. However, it is seen that allergic reactions commonly affect those who have a family history of allergies.

Such people are more susceptible and vulnerable to attacks of allergy than those without a family history.

What is the definition of allergy and how does it develop?

Allergy is defined as an abnormal response of the body’s defense mechanism to an external substance – a substance that the body foresees as an enemy or a damaging force.

This substance may have entered the body through inhalation or ingestion or by injection or it may just have had skin contact.

Here is a simpler way to put it:

How and why you get allergy? Its causes

Our body has a defense mechanism, which fights off any unwanted substances that come in contact with it.  Those substances could be viruses, bacteria, or parasitic worm, which enter the body through anything that you have eaten or breathed in, or through a wound in the skin.

The immune or the defense system of our body consists of a network of cells, tissues, and organs that work together and protect the body from any harm that these invading organisms can cause.

The white blood cells (WBCs), also called leucocytes or leukocytes, are among the more active and important cells of the immune system. The mast cells are a type of white blood cells, which play a fundamental role in the regulation of the immune system of the body.

The invading substance is called the antigen and the immune cells  (immunoglobins E) are called the antibodies. The defense interaction that occurs between the antigen and the antibodies is called the antigen-antibody reaction.

This reaction triggers the release of certain chemicals, of which histamine is the main component.

This antigen-antibody reaction manifest itself in various ways by producing signs and symptoms of allergy. Note that not all people develop manifestations to this reaction.

In an allergy, the immune system overreacts to the allergen by directing the immune cells against it. This results in an antigen-antibody reaction, which manifests in allergy symptoms.

The first time you are exposed to an allergen, you may not develop any reaction. But, the immune system starts to produce antibodies against that allergen.

The next exposure to that same allergen will evoke an allergic reaction because the antibodies are now present in your blood to cause an antigen antibody reaction.

Allergic reactions or allergy symptoms may manifest as simple skin rash or can come as an anaphylactic shock due to injection of drugs like Penicillin. An anaphylactic shock can be life threatening and is to be treated on an emergency basis.

How do you know if you are allergic to something?

It is said that anything under the sun can cause allergy, including the sun itself. Therefore, sometimes it can be difficult to know the reason, which has caused the allergic reaction.

However, the allergic victim from his pre-allergic circumstances, himself may be in a position to determine what has caused his allergy.  He should try to identify anything; he has come in contact with or eaten out of routine, which could be the reason for his allergic reaction.

Trigger factors that can cause allergy

There are, however, certain common known allergens, that can be the reason behind your allergy. They are:

  • Skin contact with pollen dust, animal hair and dander, fur, certain weeds on a farm
  • Other common allergens, which can cause skin allergy are metals, plants, cosmetics, latex, medications and perfumes.
    • Among the metals, the most common ones that can give rise to allergy are gold and nickel found in jewelry products,  cobalt chloride found in hair dyes and antiperspirants
    • A mercury compound called Thimerosal used as a preservative in vaccines
    • Formaldehyde used as a preservative in various products
    • Neomycin sulphate used in topical antibiotic powders, creams and ointments
  • Cigarette smoke and diesel fumes can also cause eye allergy
  • Inhalation of certain incense aromas or smoke, or pollen released by weeds into the air
  • Certain people react to cold climates while some to hot climates
  • Stings from insects, especially bees
  • Extreme emotion
  • Ingestion of drugs like antibiotics and aspirin
  • Eating of certain foods, especially seafood like shellfish, crabs, and lobster, peanuts, eggs etc.
  • Anaphylaxis is a severe form of allergy, which is caused by injection of the drug, penicillin. It can be fatal.

Common areas of the body affected by allergy

The eyes, nose, sinuses, and throat

These parts of the body are affected due to breathing in of allergens. The nasal lining becomes swollen and produces excessive mucus. You may get a watery or a blocked nose and you may even have excessive sneezing. Your eyes may water and you may get a sore throat.

The chest and the lungs

The lungs are affected due to breathing in of an allergen or allergens. The lining of the airway tubes gets swollen and secrete mucus. This can cause blockage of the airway passage and make breathing difficult. Asthma is the presenting symptom.

The stomach and intestines

Common allergens, which cause stomach allergy include peanuts, seafood, dairy products and eggs. Symptoms include an upset stomach.

 The skin

Skin allergy occurs due to direct contact of te skin with the allergen. This skin allergy may manifest as urticaria (hives) or eczema. Hives present as white itchy bumps and eczema as dry, red, itchy skin.

 

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