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Allergy - Allergy symptom, treatment, causes

An uncomfortable, and sometimes dangerous body response induced by an immunological reaction to an external factor called an allergen. The response can vary from common skin reactions like swelling, redness and rash, to conditions of extensive cell destruction which may cause major organ damage and may be life threatening.

Certain critical areas, like the airway, may respond with potentially dangerous swelling and spasm (seestridor,larynx,anaphylacticshock,bronchialasthma) When an allergy is suspected, an attempt is made to identify the allergen. This is not always successful The treatment therefore indudes an "avoidance list" which may read arbitary, but is based on the commoner allergens met with in daily life. The responses of allergy are mediated by a number of chemicals, the commonest of which is histamine.

Allergy affects the lives of thousands of people every year and for some it is a potentially life threatening disease. Allergies affect up to 40 per cent of the population. Allergy has different names depending upon where in body it occurs. Common Allergies are Asthma, House Dust Mite Allergy, Food Allergy, Pet Allergy, Pollen Allergies, Insect Sting Allergy. In an asthma attack the smooth muscles of the lungs go into spasm with the surrounding tissue inflammed and secreting mucus into the airways. Dust mites are microscopic organisms found in homes and are the primary cause of allergies related to dust . A food allergy is any adverse reaction to a food or food component involving the body's immune system . The allergy is more usually an immune reaction to a protein (an allergen) found in the saliva, dander (dead skin flakes) or the urine of an animal. While grass pollens are generally the most common cause of hay fever (seasonal allergic rhinitis), other pollen types are also important.

Allergic reactions to insect stings can be so severe that death may occur within the few minutes a sting. Some adverse reactions to foods do not involve the immune system and are known as food intolerance , e.g. food poisoning or the inability to properly digest certain food components such as lactose or gliadin . Sometimes enough inflammatory chemicals are released to cause a reaction throughout the body, such as hives, decreased blood pressure, shock, or loss of consciousness. Fatigue is also common in allergy season. Gamma globulins are normally present to fight bacterial infections. Thus, the diameter of the airways is reduced causing the characteristic wheezing as the person affected breathes harder to get air into the lungs.

Treatment of Allergy is with drugs that control the response, avoidance of identified allergens, and supportive treatment to contain organ damage. A hereditary incidence is often noted in allergic disorders.

What is Allergy ?

Allergy is a condition in which the body's immune system produces antibodies against certain substances (known as allergens) that do not normally cause antibody formation. Common allergens are pollens, animal hair, feathers, house dust, house mites and certain food and drugs. When an allergy is established, exposure to the allergen causes a reaction that leads mast cells to release histamine, the culprit chemical in allergic reactions. Histamine causes disturbances of blood flow such as rashes, redness, and swelling of tissues, and involuntary muscle activity such as constriction of the muscles around the airways in asthma. Other common allergic disorders are Hay Fever. Eczema, contact dermatitis and Hives. The most severe reaction, fortunately rare, is ANAPHYLAXIS, which can be life-threatening.

Diagnosis of Allergy

Finding the allergens may be straight-forward if, for example, taking a particular drug or contact with a particular plant or chemical is always followed by a reaction. However, some people are allergic to a variety of substances, making the detective work much more difficult. Skin-testing often helps to identify the culprit or culprits. This involves injecting tiny amounts of suspected allergens into the skin of the fore arm. Responsible allergens cause a red lump to appear at their injection site.

Treatment of Allergy

Avoidance of the allergen is advised, but if this is unknown, or staying away from it is impossible, some allergic reactions can be prevented by the regular use of ANTIHISTAMINE DRUGS or steroid medications. Alternatively, anti-histamines may be used to quell each attack. When a specific allergen is identified, attempts may be made to desensitise the patient to it.