Asthma And Allergies: What’s The Connection?
Old airport road, Bengaluru Feb 22, 2017
Asthma is an inflammatory disease of the windpipes (i.e. the bronchial tubes) which carry air into the lungs. It involves narrowing of the bronchial tubes causing an obstruction to the air flow leading to breathing difficulties. There are several types of asthma based on the causes. Common causes include infections, exercise, tobacco, cold weather, allergens, emotions, and certain medicines. Asthma triggered by allergens such as pollen, dust mite, etc. is called as allergic asthma.Asthma and allergies often occur hand-in-hand. About half of the cases of asthma are directly related to allergies. So let us understand the connection in detail.
How is the allergic response produced in asthma?
Allergic reaction and asthma attack are not very different from each other except for the location of the reaction.
In the case of an allergic reaction, your immune system wrongly identifies the harmless substances such as pollen grains as harmful invaders. The antibodies called Immunoglobulin E (IgE), are therefore produced against these allergens. These antibodies land on a mast cell which when exposed to another similar allergen causes the opening of the mast cell. This releases the chemicals called histamines which cause the allergic reaction. If this allergic response occurs in the nose, then it causes congestion and sneezing. A similar kind of reaction which occurs in the lungs lead to asthma. The allergic response in the lungs leads to inflammation and constriction of the airways leading to the difficulty in breathing.
What are the allergens which commonly trigger asthma?
If you have allergic asthma, it can be due to any of the following common triggers.
- Pollen grains – These are the tiny particles produced by the flowering plants especially during morning hours (5 AM to 10 AM). The period of pollination is different for different plants. In general, the pollen is high from the month of February untill October.
If you are allergic to pollen, then limit your outdoor activities during the periods of high pollen. Stay indoors with windows shut to the extent possible.
- Animal dander – Pets such as cats, dogs, rabbits, etc. shed their fur or feather which gets deposited on the carpets, bed sheets and can trigger allergic asthma.
Maintain separate home for pets and stay away from them as much as you can.
- Insects – The droppings of the insects such as cockroaches can trigger asthma symptoms in a few people.
Use insect sprays and maintain low humidity in the rooms. Cover the food items properly.
- Food allergies – These are more common in adults when compared to children.
Read the labels on the food packs and avoid those foods you are allergic to.
- Molds and mildews – These are fungi which commonly grow in a damp and humid environment.
The best method to prevent the growth of molds and mildews is to reduce moisture in the rooms using dehumidifiers.
- Dust mite – Dust mites are the major indoor triggers for asthma. These are microscopic pests which mainly grow on the indoor substances such as bedding, pillows, mattresses, carpets, curtains, furniture, etc.
Wash the mentioned clothing regularly and dry them thoroughly to reduce or prevent the growth of dust mites in your house.
During October and December, you are more likely to get exposed to the allergens. So take prophylactic measures.
How is the diagnosis made?
Your physician orders for an allergic test to check if there is any association between your symptoms and allergy. A family history and medical history will also be taken. For a more precise identification, a skin test, and a blood test may be performed.
In the skin test, a drop of the suspected allergen is placed on your skin. After a few minutes, the physician examines your skin for the presence of any reaction. If swelling occurs, then the test is considered as positive, i.e. you are allergic to the substance. The test is harmless and painless.
Check if you are at risk
If you have a family history of allergies, then you are at a high risk of getting allergic asthma. If you have the genes restricted to your nose, then you will have allergies only in the nose. If you have more genes then the bronchial effects appear. Also, your risk is high if you have hay fever or other allergies yourself.
What are the treatments for allergic asthma?
Treatments are designed against both allergies and asthma symptoms. They include:
1) Allergy shots (immunotherapy): In this approach, the response of your immune system to the allergens is gradually reduced with the allergy shots. The shots are given in the form of injections of increasing doses of the allergens you are allergic to, given over 3-5 years. As your immune system develops tolerance to the allergens, its response is diminished with the next exposure. Thus, the symptoms of asthma also are addressed.
2) Anti-immunoglobulin E (IgE) therapy: This therapy interferes with the production of IgE antibodies, thereby preventing the allergic reaction and the asthma symptoms.
3) Leukotriene modifier: This therapy controls the production of histamines which are released during the allergic reaction.
If you have severe symptoms, then other medications may be given to treat your condition. However, controlling the allergens at home is the best way to keep you away from the asthma attacks. Identify and avoid the substances which trigger allergic reactions in you. Your allergic response and asthma symptoms can change with time which requires a modified treatment. It is important for you to learn the signs of your asthma flaring up to act accordingly.
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