What Causes Allergies, Allergy Testing, Medical Treatments, Non-Medical Treatment/Prevention, Desensitisation Treatments
Hay fever, medically referred to as allergic rhinitis is a common allergic condition that refers to a group of allergic hypersensitivity reactions in the nasal mucosa and the conjunctiva of the eye. Contrary to what the name “hay fever” suggests, it is not caused by hay and it seldom results in fever. Allergic rhinitis affects around 18% of children and adults in Australia and New Zealand.
Hay fever (allergic rhinitis) is caused by an allergic response to airborne environmental allergens (indoor or outdoor) such as pollens, dust mites, perfume, pet fur or dander, mold or fungi, and cigarette smoke. People who are allergic to these airborne environmental allergens may experience the following symptoms:
- runny nose
- nasal congestion
- watery, red, or itchy eyes
- itching throat
- blocked ears
- sinus pain
What Causes Allergies
Hay Fever occurs when the immune system mistakenly identifies these airborne environmental allergens as something harmful and launches an “attack” to neutralize the threat. The immune system then triggers the release of an antibody called immunoglobulin E (IgE) to neutralize the threat. A chemical known as histamine released by the immune system is the primary culprit for the common symptoms associated with hay fever.
It is not clear yet what causes the immune system to launch the “attack”, however, there are certain factors that increase your risk of developing allergic rhinitis. Some of the most common triggers that cause allergies in people at different times of the year and in different environmental conditions are:
- Pollens – there are more than 30 different types of pollens that can cause allergies in people and they originate from different sources such as grass, trees, and weeds. It is possible for a person to be allergic to more than one type of pollen.
- House Dust – house dust also contains a number of pollutants (both organic and inorganic) that can trigger allergies. Some of the common allergens found in house dust are dirt, debris, dust mites, fibers, hair, smoke, insects, mammalian dander, saliva and feces from pets, insects, and mites.
- Fungal Allergens – fungi and mold present in the indoor or outdoor environment also produce large quantities of allergenic spores.
- Pets – household pets such as dogs, cats, birds, chickens, etc are an important source of domestic allergens and can cause severe allergies in people.
- Occupational Irritants – common allergens found in workplaces include different forms of fumes, gases, dust, chemicals, enzymes, powders, asphalt, solvent vapors, diesel exhaust, ammonia, and wood dust.
Whether you experience seasonal allergic rhinitis – occurs in spring, summer, or early fall when the airborne grass pollens are at their peak, or experience the symptoms all year long (perennial allergic rhinitis), you need to visit an allergist to help you find the appropriate treatment option for your allergies. A clinical immunologist/allergy specialist may conduct a few allergy screening tests to identify the type of allergens disturbing you. The two main allergy tests your doctor may recommend are:
- Skin Prick Test – skin prick test is the easiest, most sensitive and generally the least expensive test to identify allergens. In this test, the skin of the person is either pricked with a tiny amount of known allergen or an allergen is injected under the skin. If the skin shows a reaction to the presence of allergen/s, this would confirm that you have been sensitized to the allergen in question.
- Blood Test – a blood test is conducted to check for the presence of certain antibodies, i.e. E (IgE) which is produced by the body when it comes into contact with the pollens that cause hay fever.
Although there is no cure for allergic rhinitis (hay fever), the symptoms associated with this common allergic condition can be relieved or managed by using various treatment modalities.
The best and easiest way to manage the symptoms associated with seasonal or perennial form of allergic rhinitis is to avoid the allergens that trigger them. Following steps can be taken to avoid indoor or outdoor exposure:
- keep windows, doors, vents closed to keep the allergens at bay
- use “mite-proof” covers
- wash your bed sheets, sofa covers, comforter covers, blinds, curtains frequently
- keep the indoor humidity between 30 -50%
- keep the floors, carpets, rugs, cleaned at all times
- avoid going outdoors during the peak allergy season
- wear sunglasses when outdoor
- wear pollen mask when outdoor
Sometimes it’s hard to avoid the allergens that trigger hay fever with these simple steps, under such circumstances your doctor (allergist) may prescribe different medications to relieve different symptoms. Various medications available to treat different symptoms of hay fever are:
- Antihistamine tablets, eye drops, syrups, and intranasal sprays – effective for itching, sneezing, and watery eyes
- Intranasal corticosteroid sprayers (INCS) – effective for blocked nose, dryness and irritation in the nasal passage
- Combination medications (antihistamine + corticosteroids) – effective for itchy eyes, sneezing, watery eyes, and blocked nose
- Decongestant sprayers – for unblocking dry, blocked nose
- Decongestant tablets – effective for blocked nose
Non-medical treatment for hay fever may include the use of natural products and alternative therapies.
- saltwater/saline nasal sprays
- herbal medicines
Desensitisation also known as allergen immunotherapy is used to reduce the severity of symptoms and dependency for regular use of medications. Immunotherapy involves gradually administering small amounts of allergen extracts by means of drops, tablets, sprayers, or injections. It is a long-term treatment and may take up to 3-5 years to achieve good results. Two types of immunotherapy are available:
- Allergy shots
- Sublingual tablets