Dr Michael Shen, MBBS MPH FRACGP
Allergic rhinitis, commonly known as hay fever, is a common allergic reaction affecting up to 30% of the Australian population. It is the inflammation of the nasal mucosa caused by exposure to environmental allergens such as house dust mites, grass pollens, tree pollens and animal dander. In this article, we will discuss the prevalence, causes, diagnostic skin prick testing, management and desensitisation immunotherapy for allergic rhinitis.
Prevalence:
Allergic rhinitis is a common condition affecting people of all ages, but it is more common in children and young adults. The prevalence of allergic rhinitis varies depending on location and environmental factors. In Australia, allergic rhinitis affects up to 20-30% of the population, while in developing countries, the prevalence is lower, ranging from 10-20%.
Causes:
Allergic rhinitis is caused by an allergic reaction to allergens that are inhaled through the nose. When an allergen enters the nose, it triggers an immune response, causing the release of histamine and other chemicals that cause inflammation and irritation of the nasal passages. Common allergens include house dust mites, grass/weed/tree pollens, animal dander and mould spores. Other factors that may exacerbate allergic rhinitis include change in temperature or humidity, air pollution, smoke, and strong odours.
Diagnostic testing:
Skin prick testing (SPT) is a diagnostic test used to determine the allergens that are triggering an individual’s allergic rhinitis. During the test, the skin is pricked by a plastic lancet with a small amount of allergen. If the individual is allergic to the allergen, a small bump will appear on the skin, indicating a positive reaction. This test is more accurate than a blood test for aero allergens.
SPT is a safe and effective way to diagnose aero-allergies and allergic rhinitis. Aero-allergen skin prick testing can be performed at the Madison Medical Practice Hornsby with Dr Michael Shen for patients 6 years old and above.
Before the test, the individual should avoid antihistamines (Clarityne/Zyrtec/Telfast/Desonex etc.), Dymista and Ryaltris for at least 7 days to prevent any interference with the test results. If the test results are positive, the individual can be advised on minimisation strategies, specific treatments and desensitisation immunotherapy to manage their allergic rhinitis.
Skin prick testing will take approximately 30 minutes and costs $150. There is a Medicare rebate of $35 for skin prick testing.
Treatment:
Effectively treating moderate to severe allergic rhinitis requires a combination of the new intranasal corticosteroid and olopatadine nasal spray (Ryaltris), medicated sinus rinse and antihistamines as part of a treatment plan tailored to each patient.
Allergen desensitisation Immunotherapy:
Allergen desensitisation immunotherapy, also known as allergy shots, is a treatment option for individuals with allergic rhinitis symptoms which are not well controlled on regular treatments. Immunotherapy works by gradually exposing the individual to small amounts of the allergen over a period of several months to desensitise the immune system to the allergen.
Immunotherapy is a long-term treatment that requires monthly injections over a period of 3-5 years. The treatment is effective in significantly reducing the severity of allergic rhinitis symptoms and it may treat and prevent the development of nasal obstruction and asthma.
Allergic rhinitis is a common allergic reaction that affects a significant proportion of the population and can severely impact sleep and day to day activities. The condition can be readily treated with newer medical therapy. SPT is a safe way to diagnose allergic rhinitis and allow the initiation of allergen immunotherapy treatment for individuals who have not responded to other treatments.
If you suspect that you may have allergic rhinitis, contact Madison Medical Practice Hornsby for an accurate diagnosis and appropriate management.
Click here to book an appointment with Dr Michael Shen.
All Consulting GPs & Allied Health Professionals operate their own medical businesses within the Madison Medical Practice.