Kinds of Allergy and Causes Definition of Allergy
Allergy refers to an exaggerated reaction by our immune system in response to bodily contact with certain foreign substances. Exaggerated because these foreign substances are generally regarded by the body as something harmless and no response occurs in people who are not allergic. The bodies of people who are allergic to recognize foreign material and part of the immune system is activated. Allergic materials are called "allergens". Examples of allergens include pollens, dust mites, molds, and foods. To understand the language of allergy is very important to remember that allergens are substances foreign to the body and can cause allergic reactions in certain people.
When allergens come into contact with the body, he causes the immune system to develop allergic reactions in people allergic to it. When you react inappropriately to the allergen are generally not harmful to others, you have an allergic reaction and can be referred to as allergic or atopic. people who are predisposed to allergy is called allergic or atopic.
Austrian pediatrician named Clemens Pirquet (1874-1929) first used the term allergy. He referred to both immunity lucrative and dangerous as an allergic hypersensitivity. The word allergy comes from the Greek words "allos," meaning different or changed, and "ergos" meaning work or action. Allergy broadly referred to as "altered reaction". The word allergy was first used in 1905 to describe the adverse reactions of the children given repeated injections of horse serum to fight infection. The next year, the term allergy is proposed to explain the reactivity of these unexpected changes.
Allergy Facts
* An estimated 50 million Americans are affected by allergic conditions.
* The cost of allergies in America is more than U.S. $ 10 billion annually.
* Allergic rhinitis (nasal allergies) affects about 35 million Americans, 6 million of whom are children.
* Asthma affects 15 million Americans, 5 million of whom are children.
* Numbers of cases of asthma doubled during the last 20 years.
Allergy Causes
To help answer this question, let us look at some examples of common household. A few months after the arrival of a cat in the house, my father started getting the itchy eyes and episodes of sneezing. One of three children developed a cough and wheezing, especially when the cat into the bedroom. Mother and two other children did not experience any reaction to the presence of cats. How do we explain this?
The purpose of the immune system is to mobilize its power to assault and destroy the enemy. One way to do this is to create protective proteins called antibodies that specifically targeted against particular foreign substances. These antibodies, or immunoglobulins (IgG, IgM, IgA, IgD), are protective and help destroy a foreign particle by attaching itself to its surface, thus making easier the other immune cells to destroy it. However people who are allergic, develop a specific type of antibody called immunoglobulin E, or IgE, in response to certain foreign materials that are generally harmless, such as cat dander. In summary, the immunoglobulins are a group of the protein molecules acting as antibodies. There are 5 kinds of different types: IgA, IgM, IgG, IgD, and IgE. IgE is the allergy antibody.
In the example of animals cats, father and youngest daughter developed IgE antibodies directed in large numbers against cat allergens, cat dander. Father and daughter are now sensitized or prone to develop allergic reactions on subsequent and repeated exposure to cat allergen. Typically, there are periods of "sensitivity" that range from months to years before an allergic reaction. Although allergic reactions may occasionally occur on first exposure to the allergen, certainly before there is contact so that the immune system to react in this way.
IgE is an antibody that is owned by all of us in small quantities. People who are allergic, however, produce IgE in large amounts. Normally, antibodies are important in protecting us from parasites, but not from cat dander or allergens. During the sensitization period, cat dander IgE is overproduced and coats certain cells that contain a potentially explosive chemicals. These cells are capable of causing an allergic reaction on subsequent exposure to dander. This is caused by the reaction of cat dander with the dander IgE irritates the cells and leads to the release of various chemicals, including histamine. These chemicals, in turn, causes inflammation and allergy symptoms are typical. This is how the immune system become overactive and prepared to cause an allergic reaction when stimulated by allergens.
Time of exposure to cat dander, mother and two other children generate classes other antibodies, none of them cause allergic reactions. In the family members who are not allergic, dander particles are eliminated by the immune system and the cat has no effect on them.
Who's at Risk and Why?
Allergies can develop at any age, possibly even in the womb. They generally occur in children but may cause symptoms for the first time in adulthood. Asthma may be prolonged in adults while nasal allergies tend to diminish in old age.
Why, might you ask, some people are sensitive (sensitive) to specific allergens which most are not sensitive? Why are people allergic to produce more IgE than those not allergic? It seems the main factor that sets it apart is the descent. For some time, has been known that allergic conditions tend to cluster / clustered within families. Your own risk associated with a history of allergy develop allergies from your parents. If none of your parents are allergic, your chances of getting allergies is about 15%. If the parents are allergic, your risk increases to 30% and if both are allergic, your risk is greater than 60%.
Although you may inherit a tendency to develop allergies, you may in reality never have symptoms. You also should not inherit the same allergies or diseases the same as your parents. It remains unclear what determines what ingredients that trigger allergic reactions in people. Moreover, diseases which may be developed or how heavy the symptoms that may occur, is unknown.
Other major pieces of the puzzle is environmental allergies. It is clear that you must have a genetic tendency and in exposure to an allergen that develop allergies. In addition, more intense and had repeated exposure to an allergen and occurs early in life, are more likely to develop allergies.
There are other important influences that may conspire to cause allergic conditions. Some of these include smoking, pollution, infection, and hormones.
General Conditions of Allergy and Symptoms and signs
Body parts that tend to react to allergies include the eyes, nose, lungs, skin, and stomach. Although a variety of allergic diseases may present differently, they all come from the response / excessive immune reaction to foreign substances in people who are sensitive. The following brief descriptions will present an overview of allergic disorders are common.
Allergic rhinitis
Allergic rhinitis ("hay fever") is the most common of the allergic diseases and refers to seasonal nasal symptoms caused by pollen. Year-round allergic rhinitis or perennial allergic rhinitis (perennial) is generally caused by allergens in the house / room, such as mites (dust mites), animal dander, or molds. It can also be caused by pollen. The symptoms come from inflammation of the tissue that lines the inside of the nose (coatings or mucous membranes) after allergens are inhaled. Adjacent areas, such as the ears, sinuses, and throat may also be involved. The symptoms most commonly include:
* A runny nose
* Nasal congestion
* Sneeze
* Itchy Nose
* Ears and throat are itchy
* Post nasal drip
In 1819, an English physician, John Bostock, hay fever first described by detailing the symptoms of seasonal nasal itself, which he calls "summer catarrh". The condition is called hay fever because it thought to be caused by a "new hay".
Asthma
Asthma is a respiratory problem that comes from inflammation and spasm (spasm) of the lung airways (bronchial tubes). The inflammation causes a narrowing of the airways, which restrict air flow into and out of the lungs. Asthma most often, but not always, associated with allergies. Common symptoms include:
* Shortness of breath
* Wheezing (Wheezing)
* Cough
* Chest tightness
Allergy Spy
Allergy eyes (allergic conjunctivitis) is inflammation of the tissue layers (membranes) covering the surface of the eyeball and the lower surface of the eyelid. Inflammation occurs as a result of allergic reactions and may produce the following symptoms:
* Redness under the lids and the eyes of the whole
* Eyes watery and itchy eyes
* Swelling of the membranes
Allergic Eczema
Allergic eczema (atopic dermatitis) is generally not an allergic rash caused by skin contact with allergens. This condition is commonly associated with allergic rhinitis or asthma and highlight the following symptoms:
* Itching, redness, or dryness of the skin
* Rash (Rash) in advance, especially children
* Rash around the eyes, the folds of elbows, and behind the knees, especially in children who are older and adults
Hives
Hives (urticaria) are skin reactions that occur as swelling, itching and swelling that can occur anywhere on the body. Hives can be caused by allergic reactions, such as food or medicine, but they also can occur in people who are not allergic. The symptoms are typical hives are:
* Raised red welts
* Itching great
Allergic Shock
Allergic shock (anaphylaxis or anaphylactic shock) is a life-threatening allergic reaction that can affect several organs at the same time. This response typically occurs when the allergen is eaten (eg, food) or injected (eg bee stings). Some or all of the following symptoms may occur:
* Hives or reddish discoloration of the skin
* Nasal congestion
* Swelling of the throat
* Abdominal pain, nausea and vomiting
* Shortness of breath, wheezing (wheezing)
* Low blood pressure or shock
Shock refers to insufficient blood circulation to the tissues of the body. The most common shock caused by blood loss or infection. Allergic shock is caused by vessels that dilate and "leaky", resulting in a decline in blood pressure.
There are anywhere Allergen-Allergen?
We have seen that the allergens are special types of antigens that cause allergic reactions. The symptoms and diseases caused depends largely from the entrance and the level of exposure to allergens. Chemical structure of allergens affect the course of exposure. Pollen in the air, for example, will have little impact on the skin. They are easily inhaled and so will cause more symptoms of the nose and lungs and limits the skin symptoms. While the allergens are ingested or injected and they will walk towards the other parts of the body and provoke the symptoms are far from the point of entry. For example, allergens in foods can probably speed up the release of mediator-arbitrator (mediators) in the skin and cause hives.
We will assume that the allergens are defined as: a source of materials that produce allergies (for example, cat), his own material (cat dander), or specific proteins that provoke an immune response (eg, Feld1). Feld1, from Felis domesticus (cat benign), is chemically the most important allergen in cat dander.
Allergens may be inhaled, ingested (eaten or swallowed), worn on the skin, or injected into the body either as medication or by not carefully by insect stings.
In the Air That We Breath
Breathing can be risky if you are allergic. Besides oxygen, the air contains a wide variety of particles, some poisonous, some infectious, and some are harmless, including allergens. Diseases that are common allergens from the air is hay fever, asthma, and conjunctivitis. The following allergens are generally harmless, but can trigger allergic reactions when inhaled by sensitive individuals.
* Pollen: trees, grasses, and / or weeds
* Mites
* Protein-protein animal: dander, skin, and / or urine
* Fungal spores
* Parts of the insect: cockroach, roach
In What We Eat
When these foods and ingested drugs, allergen-allegen may be able to access the bloodstream and become attached to specific IgE in cells in places as far away as the skin or nasal membranes. The ability of allergens to travel to explain how the symptoms can occur in different areas of the digestive tract. Food allergy reactions can begin with swelling of tongue or throat and may be followed by a tingling sensation (tingling), nausea, diarrhea, or abdominal cramps. Difficulty breathing with the nose or skin reactions may also occur. Two main groups of allergens are digested are:
* Food: The most common foods that cause allergic reactions are cow's milk, fish, shellfish, eggs, beans, nuts, herbs, soy, and wheat.
* Drugs (when drunk): for example, antibiotics and aspirin
We touched the skin
Allergic contact dermatitis is a skin inflammation caused by a local allergic reaction. The majority of local skin reactions do not involve IgE, but are caused by inflammatory cells. Induced rash was similar to that of a poisonous ivy rash. It should be noted that when some allergens (eg, latex) in contact with the skin, they are absorbed by the skin and can also potentially cause reactions throughout the body, not just the skin alone. For most people, however, the skin is a great barrier which can only be influenced locally. Examples of allergic contact dermatitis include:
* Latex (causing reactions IgE and non-IgE)
* Plants (poison ivy and oak)
* Substance dyes (Dyes)
* Chemicals
* Metals (nickel)
* Cosmetic-Cosmetic
Allergic contact dermatitis does not involve IgE antibodies, but involves the cells of the immune system is programmed to react when it is triggered by allergens that sensitize. Touching or rubbing the element / material that never made before you can trigger a rash sensitive skin (skin rash).
Injected Into the Body
The reactions of the most severe may occur when allergens injected into the body and get access directly into the bloodstream. This access carries the risk of general reactions, like anaphylaxis, which can endanger lives. Here are the allergens that most commonly injected, a reaction that can cause severe allergic reactions:
* Insect venom
* Drugs
* Vaccines (including allergy shots)
* Hormones (eg, insulin)
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