What is Allergy?
Allergy is an abnormally high sensitivity to certain substances, such as pollen, food, or microorganisms. These substances are known as allergens. Allergens are quite harmless to normal people but they can provoke severe allergic reactions in people who are predisposed to allergy. Asthma can have allergic factors especially in young people. The text below gives you an overview of allergy and its causes, symptoms, treatment and prevention so that you are better prepared against it.
Let me start with a story. There were two monumental houses of tourist attraction. While one of the houses was protected by a guard posted at its gate, the other house was unprotected. Due to no security, the visitors had an easy access to the unguarded house. Over a period of time, the guard at the protected house became lazy, relaxed and nonvigilant, due to which, visitors began to have easy access to this house. Then, there was a theft in the house with the guard. Now the guard became alert, attentive and hyperactive. He allowed visitors only after a thorough search. Search procedure sometimes used to result in quarrel and altercation between the visitors and the guard. In the scuffle sometimes the guard also used to sustain injuries.
This is analogous to the state of our body’s security guard. Our body’s defense mechanism has a similar way of allowing or disallowing foreign particles inside through nostrils and mouth. A normal person would tolerate most of the substances like the unguarded house that tolerated all visitors. An atopic person without allergic disease, on the other hand, is comparable to the house that is guarded by the lazy guard. Both allergic and non-allergic substances are welcomed without any protest. Finally, an allergic asthmatic child when attacked by an allergen, is akin to the hyperactive and attentive house guard who gets injuries during scuffle with visitors.
Common Allergy Diseases:
Allergy disease or reaction may involve any organ of the body. Some of the common allergies include:
- Hay Fever
- Allergic Rhinitis
- Allergic Dermatitis, Contact Dermatitis or Eczema
- Hives or Urticaria
- Allergic Conjunctivitis
- Gastric Allergy
Allergy manifestation of Organs
Allergy symptoms are easy to diagnose. The symptoms depend on the organ that is involved, as shown in the table below:
|Skin||Hives (Urticaria), Allergic Dermatitis, Contact Dermatitis, Eczema||Itching, Rash||Dry skin, Scratch Marks, Wrinkles, Dark areas around the Eyes|
|Nose||Allergic cold or Allergic Rhinitis||Sneezing, Runny nose with itching and blockage||Red and Dry skin of Nose with Abrasion|
|Eyes||Allergic Conjunctivitis||Red and Watery Eyes with Itching and Pain||Redness in Eyes|
|Lung Airways||Bronchial asthma||Breathlessness, Wheezing, Coughing, inability to speak long sentences||Thread like sputum, Wheezing, Prominent depressions at the base of Neck during
Some of the common allergens that cause allergies include:
- Pollen particularly grass pollen
- Dust mites
- Animal fur and skin flakes
- Food stuffs such as milk and eggs
- Fumes in factories
Typical symptoms of allergy are skin rashes, itching and redness of the skin, watery eyes, runny nose and sneezing. These symptoms may be with or without wheezing.
Allergic diseases are atopic in nature, meaning these diseases are related to, or caused by hereditary predisposition toward developing certain hypersensitivity reactions.
Facts about Allergy:
- The tendency to develop allergy is inherited.
- If you have allergic tendencies and are exposed to certain substances in your environment, you may develop allergies to some of those. These substances are called allergens.
- As far as asthma is concerned, the allergens that are important cause a reaction after these are inhaled.
- The allergens may be pollens, mold (fungus), certain dusts, insects, cockroaches and mites.
- Examples of allergy symptoms include itchy eyes, runny nose, asthma symptoms, eczema and rash.
- You may have one or more of these symptoms or you may have one symptom at one time and another symptom at another time.
- The timing of the allergic response may be immediate or delayed. Usually symptoms of asthma or of rhinitis begin very soon (within half an hour) of exposure to the substance you are allergic to.
- While in many cases the allergen may be obvious, yet in several instances, it is not possible to identify it. Careful observation on the part of the patient is therefore of paramount importance.
- Allergy testing and certain blood tests to identify antibodies may be recommended to help identify your allergies.
How to identify Allergens:
- Experience of patient.
- Evaluation by allergist.
- Peak flow measurement record.
- Positive skin prick test.
Through Allergy testing: Positive allergy skin prick test and positive experience of the patient.
Positive blood test: Experience of the patient is the most important factor in detection of allergens. It requires careful observation on the part of the patient and his family history for the physician to identify the offending allergens. Regular peak expiratory flow chart also helps in allergen detection. Systematic evaluation by an allergy/asthma expert helps in further identification of the incriminating allergens. However, confirmation can be done by allergy skin prick test and blood test.
Allergy Treatment strategies:
There are three approaches to allergy treatment:
- Avoidance and environmental control
- Desensitization by immunotherapy
Pharmacotherapy is the treatment of asthma with anti-inflammatory drugs given by inhalation and is the most effective approach to controlling allergies. The advantage of using the proper pharmacotherapy is that it controls asthma not only due to allergens but also due to other triggers.
Avoidance and Environmental Control is equally important and must be seriously implemented. Of course, this requires careful observation on the part of the patient and a good history by the physician to identify the offending allergen.
Once an allergy has been identified, the next step is to decrease or eliminate exposure to the allergen. This is called environmental control. Evidence shows that allergy and asthma symptoms may improve over time, if the recommended environmental control changes are made. Many of the changes are for the entire home. The bedroom is the most important, because the bedroom is where people usually spend 1/3 to 1/2 of their time.
Steps to Control Pollen Allergens
- If possible, keep windows and outside doors shut during pollen season, especially during the daytime. If you have central or room air conditioning, use it to allow you to keep windows and outside doors shut.
- Pollen exposure is highest during the midday and afternoon. Consider this when planning outdoor activities.
- If an allergen is identified, take steps to remove it from your surroundings – remove the plant or the shrub.
Desensitization by immunotherapy. This involves repeated injections of very dilute solutions of allergens for several months to years so as to build up resistance. It is a tedious, painful procedure with doubtful results and is generally not recommended. It can be dangerous too. In fact, deaths have been reported due to skin testing and desensitization. It is considered as a treatment option in the following circumstances:
- Treatment with drugs is not able to provide adequate control of asthma and is producing intolerable adverse effects
- There is definite evidence by history, skin tests and blood tests that the suspected allergen is indeed the cause of the symptoms
- Avoidance is not possible
If desensitization is indicated, it must be taken under the supervision of a trained allergist.