This is what you need to know about nasal allergies
- What is so important about nasal allergies?
- Why do nasal allergies happen?
- What am I allergic to?
- Do I need an allergy test?
- Do I need nasal endoscopy?
- How do I get my nasal allergies under control?
- How do I get rid of house dust mites?
- Can my nasal allergies be cured?
- Is there an operation that will help my nasal allergies?
- I want a diagnosis and treatment. What do I do?
What is so important about nasal allergies?
Nasal allergies can have a significant negative impact on your quality of life.
You may wake up in the mornings with “morning sinus.” Your nose feels congested, you sneeze, and have a runny nose. Your nose is probably itchy, and you may also have itchy eyes. It may take you several hours before these symptoms settle down. Or they simply may not fully settle. You may be using lots of tissues through the day.
Your nose may block up at night, and you end up breathing through your mouth and wake up with a dry, uncomfortable throat. You might also be snoring, and your sleep is not fantastic.
Dusty environments may be difficult to tolerate. But sometimes, just a change in temperature or a bump to the nose may be enough to spark off your symptoms, too.
If you have some or all of these symptoms, you probably have nasal allergies or allergic rhinitis.
Allergic rhinitis can affect our mood, concentration, productivity, and daily activities.
Furthermore, nasal allergies can contribute to or exacerbate other health conditions. For example, they can lead to sinusitis or trigger asthma attacks, complicating the management of these related conditions. Persistent inflammation and irritation in the nasal passages can also make individuals more susceptible to respiratory infections.
Why do nasal allergies happen?
Nasal allergies occur when your immune system overreacts to allergens such as dust mites, pet dander, moulds, and pollens.
When you breathe in an allergen, a series of reactions occur, known as the allergic cascade.
The allergic cascade typically involves the following steps:
- Sensitisation. When exposed to the allergen usually for the first time, the body produces an antibody known as immunoglobulin E or IgE, but there is no allergic reaction.
- Early phase reaction. Later on, re-exposure to the allergen causes the allergen to bind to the IgE produced previously. The IgE links the allergen to a cell known as a mast cell. When enough allergen is linked, the mast cell explodes, releasing a chemical called histamine, and other inflammatory mediators. This process takes place within minutes of re-exposure.
- Late phase reaction. This occurs several hours later and involves other cells such as eosinophils and mediators such as interleukines, which perpetuate the allergic reaction for up to 12 hours.
What am I allergic to?
By far, the most common cause of nasal allergies in Singapore is the house dust mite.
The house dust mite is a microscopic organism that feeds on shed skin. It likes to live in soft furniture. Moreover, it also likes warm, humid environments, making a country like Singapore the perfect habitat. There are three common varieties of house dust mite in Singapore (DP, DF, and BT).
Other common allergens include cockroach debris, pet dander, mould, and grass pollen.
These allergens are present all year round. Hence, they tend to cause persistent symptoms.
In countries with pollen seasons, nasal allergies due to pollen from trees, grasses and weeds can be seasonal.
Foods do not usually cause allergic rhinitis. Although there is some cross reactivity between house dust mite and shellfish.
Do I need an allergy test?
You can start treatment without allergy testing, but allergy testing provides two important benefits:
1. Knowing which allergen or allergens are causing the allergy can help guide allergen avoidance as part of treatment.
2. The test can identify if you are a candidate for allergen immunotherapy, a treatment that desensitises your body from the allergen.
We can test for allergies using a skin test or a blood test. Both tests are accurate and cover a panel of common allergens.
The skin test involves pricking the surface layer of the skin, usually the forearm and is not painful. Results are visible within twenty minutes. Stop taking antihistamines five days before the test as this can affect the test accuracy.
The blood test involves drawing a few mls of blood, and results take several days.
Do I need nasal endoscopy?
Nasal endoscopy is useful as part of the initial assessment of allergic rhinitis.
This assessment involves passing a thin flexible camera into the nose to examine the nose and throat. The examination defines anatomical features contributing to symptoms, such as large turbinates, deviated nasal septum, or even evidence of sinus infection or polyps.
Nasal endoscopy can also identify nasopharygeal cancer. The risk of nasopharyngeal cancer may be slightly higher in Asian allergic rhinitis sufferers. [1]
The following symptoms could indicate a more serious problem and nasal endoscopy is strongly advisable:
- Nose bleeds, especially if scanty on blowing the nose.
- Symptoms on one side.
- Persistent pus-like nasal discharge.
- Persistent headache.
- Blocked ear.
How do I get my nasal allergies under control?
There are several medication options that can help bring allergies under control
Antihistamines
Antihistamines can reduce sneezing, itchy nose and eyes, and runny nose. They work by blocking histamine (one of the main mediators of allergic reactions) from binding to H1 histamine receptors on nerves, blood vessels and glandular cells, thereby blocking the body’s response when exposed to an allergen. You only need to use an antihistamines when you have symptoms. Hence they are helpful when symptoms occur intermittently. First generation of antihistamines can enter the central nervous system across the blood brain barrier and cause sedation. This can help promote sleep in some patients. However we generally prefer to use non-drowsy newer generation medication.
Steroid Nasal Sprays
Steroid nasal sprays are the cornerstone of first-line treatment for persistent rhinitis of any severity. They work much better than antihistamines when it comes to improving blocked nose. In addition, they also reduce sneezing, runny nose, and itchy eyes.
Steroid nasal sprays work on the lining of the nose by blocking multiple inflammatory mediators involved in both early and late phases of the inflammatory process. Hence, they are useful to relieve both initial and persistent symptoms.
Steroid nasal sprays work directly on the nose and hardly enter the blood stream. Hence, they are safe to use even in children as young as two years old. [2]
However, prolonged continuous use for up to a year could slow down growth rates in children by 2 to 3 mm per year due to slight but gradual steroid absorption. [3] Concurrent use of steroid inhalers for asthma could add to this problem. To avoid this we reduce the spray dose once symptoms are controlled. It may also be useful to consider other therapies such as immunotherapy when long-term medication is necessary.
Do remember, when using nasal steroids, that it may take a few days to get the full effect. So, although you may notice improvement after the first dose, do not expect instant success!
In addition, it is important to learn how to use the spray correctly to achieve the optimal clinical response.
Decongestant Nasal Sprays
Decongestant nasal sprays can help to quickly relieve a blocked nose. They work by constricting the small blood vessels in the nasal lining, resulting in the lining shrinking and less swelling. Prolonged decongestant spray use can cause a rebound of worsening stuffiness each time the spray wears off, leading to a vicious cycle of increased use and a condition called rhinitis medicamentosa. Hence, you should not use the spray for more than five days in most circumstances.
Decongestant Tablets
Decongestant tablets can also help open up the nasal passages quickly. This improves ventilation and drainage of the sinuses next to the nose. Decongestants are often combined with antihistamines, indicated by the letter “D” after the antihistamine name. Decongestants can cause side effects like jitteriness, insomnia, palpitations, and raised blood pressure in susceptible patients. Hence, you should not use them for extended periods.
Nasal Irrigation
Rinsing your nose with saline can wash the allergens from your nasal passages and reduce allergic rhinitis symptoms in both adults and children, with no reported adverse effects. Hence, it can provide a cheap, safe, and acceptable means of reducing reliance on antihistamines and steroid nasal sprays in some patients. [4]
Leukotriene Inhibitors
Leukotriene inhibitors block the action of leukotrienes, which cause tightening of airway muscles and production of excess mucus. We usually use leukotriene inhibitors when we are treating allergic rhinitis and asthma together.
How do I get rid of house dust mites?
Getting rid of house dust mites completely is nearly impossible, but reducing dust mite populations can improve your allergic symptoms.
Start with the small steps that are likely to produce the most benefit:
Soft Toys
Children (and some adults) often have a lot of soft toys in bed. Now is the time to choose one favourite cuddly toy and put the others away in a vacuum bag. Give the favourite toy a good bath too!
Soft Furnishings
Carpets, cushions, and upholstery are prone to accumulating dust mites. Opt for hard flooring over carpets. Remove all unnecessary soft furnishings. And choose non-fabric or washable furniture covers.
Bedding Care
Dust mites commonly inhabit our bedding including mattresses and pillows. Wash bed sheets, pillow cases, and blankets, if possible with hot water (55-60 °C), weekly to remove dust mites. Consider using allergen-proof covers on pillows and mattresses. Alternatively, use a standard mattress cover but wash this regularly. You may need to replace mattresses and pillows that are very old.
Frequent Cleaning
Vacuum or mop the floor regularly. Try to use a vacuum cleaner equipped with a HEPA filter. This helps trap dust mites and their waste. In addition, use a damp cloth to wipe surfaces to avoid spreading dust into the air. Finally, minimise clutter where dust can collect, including books, magazines, and decorative items. This makes cleaning easier and reduces dust accumulation.
Manage Pet Allergens
Bathe pets regularly and keep them out of bedrooms and off the bed! Even if you are not allergic to your pet, they can add to the dust mite load.
Air Purifiers
These can help when used as part of a broader strategy, including other rmeasures described above. Your air purifier should have a HEPA filter, and its specifications should match the room size. During the day you should open the windows to ventilate and sun the room.
Aircon, Fan, or Natural Ventilation?
There is no one-size-fits-all solution here! However, here are a few pointers:
- If you use an air-conditioner, clean the filters regularly.
- Dust mites are most comfortable in temperatures from 20 to 28 °C. Setting the temperature below 20 degrees could mean less active dust mites. However, this may not be comfortable for everyone, or energy efficient!
- Using a dehumidifier in addition to air conditioning to lower relative humidity levels below 50% could lower dust mites further but will almost certainly raise your electricity bill!
- Avoid using a ceiling fan, as this can circulate dust and make allergies worse.
- If you use a floor fan, blow the fan away from your face rather than towards it.
- If you sleep without air-conditioning or a fan, open the windows to improve air circulation. However, traffic pollution could enter the room if you live on a low floor in a built-up area and mould could enter if you live in a wooded area. If you live on a high floor, this may be less of a concern.
Can my nasal allergies be cured?
Allergen immunotherapy (AIT) is a well-established treatment that can cure allergies or provide long-term control.
Just as your immune system can be sensitised to an allergen, so it can also be desensitised. We do this by administering controlled quantities of allergen to the body over an extended period. As a result, the immune system becomes trained to react less to the allergen.
Currently, the most efficient way to deliver AIT is by administering the allergen as a soluble tablet or a spray under the tongue, a process known as sub-lingual immunotherapy or SLIT. You will need to take the treatment every day for three years to achieve lasting benefit.
SLIT is safe for children as young as four years old. However, in the early stage of treatment, particularly during the first month, allergic symptoms can increase, together with discomfort or swelling (typically mild) at the floor of the mouth or around the lips. You will need to take the first dose in the clinic. This is so we can check that you are taking it correctly, and make sure that no unwanted reactions occur. You can take the subsequent doses at home. Importantly, no one has ever died from using SLIT, in contrast to SLIT’s counterpart treatment, sub-cutaneous immunotherapy (sometimes referred to as allergy shots), in which airway swelling leading to death is a rare but recognised complication.
Is there an operation that will help my nasal allergies?
Cryoablation of the posterior nasal nerves (Clarifix) is a minimally invasive surgical procedure that can successfully reduce chronic rhinitis symptoms.
This procedure involves freezing the nerves at the back of both sides of the nose, which control the runny discharge, sneezing, and congestion, the hallmark symptoms of allergic rhinitis. We can perform the procedure under local or general anaesthetic. However the latter is a lot more comfortable for patients and I recommend this if possible. Read more about cryoablation of the posterior nasal nerves.
Radiofrequency turbinate reduction is another minimally invasive procedure that improves nasal breathing. We sometimes perform this procedure together with posterior nasal nerve cryoablation. The procedure uses a needle probe to apply a radiofrequency current under the surface of the turbinate to shrink the turbinate. This does not treat the allergy but does help open the nasal passages and improve breathing. Read more about radiofrequency turbinate reduction.
I want a diagnosis and treatment. What do I do?
Read more about services for nose, sinus, and allergy at Advanced ENT Centre.
Read more about conditions related to nose, sinus and allergy.
Contact us at Advanced ENT Centre to make an appointment.
Take control of your allergies and your well-being!
References
[1] Wang Y, Koh KK, Chua E, Kiong KL, Kwan YH, Charn TC. The association between chronic sinonasal inflammation and nasopharyngeal carcinoma – A systematic review and meta-analysis. Am J Otolaryngol. 2024 Mar-Apr;45(2):104206. doi: 10.1016/j.amjoto.2023.104206. Epub 2023 Dec 18. PMID: 38141564. [go back]
[2] Donaldson AM, Choby G, Kim DH, Marks LA, Lal D. Intranasal Corticosteroid Therapy: Systematic Review and Meta-analysis of Reported Safety and Adverse Effects in Children. Otolaryngol Head Neck Surg. 2020 Dec;163(6):1087-1096. doi: 10.1177/0194599820931454. Epub 2020 Jul 14. PMID: 32660332. [go back]
[3] Lee LA, Sterling R, Máspero J, Clements D, Ellsworth A, Pedersen S. Growth velocity reduced with once-daily fluticasone furoate nasal spray in prepubescent children with perennial allergic rhinitis. J Allergy Clin Immunol Pract. 2014 Jul-Aug;2(4):421-7. doi: 10.1016/j.jaip.2014.04.008. Epub 2014 May 21. PMID: 25017530. [go back]
[4] Head K, Snidvongs K, Glew S, Scadding G, Schilder AGM, Philpott C, Hopkins C. Saline irrigation for allergic rhinitis. Cochrane Database of Systematic Reviews 2018, Issue 6. Art. No.: CD012597. DOI: 10.1002/14651858.CD012597.pub2. Accessed 04 August 2024. [go back]