Nose & Sinus
Allergy and the Nose
What are allergies?
An allergy is your immune system’s over-reaction to a foreign substance (allergen). During an allergic reaction, your immune system perceives an allergen, which would be harmless to most people, as a threat. Your body attacks the allergen with antibodies and chemicals are released by mast cells (special white blood cells). These chemicals cause the unwanted inflammatory response that we know as an allergy.
Allergic disease is increasing in Australia, and currently affects more than four million Australians.
How can allergies affect my nose?
Allergies that affect the nose are called allergic rhinitis (“hay fever”). Common symptoms of allergic rhinitis are:
- Watery, runny nose
- Blocked nose
- Sneezing
- Post-nasal drip and cough
- Itchy, red or watery eyes
- Red, swollen eyelids
- Blocked sensation in ears
Is allergic rhinitis dangerous?
Allergic rhinitis is not usually dangerous. However, it may be linked with asthma, which could be life-threatening in severe cases. Anaphylaxis is a severe allergy, which unlike allergic rhinitis, involves multiple body systems. Anaphylaxis is life-threatening if not immediately treated.
Why is it important to treat allergic rhinitis?
Allergic rhinitis can cause significant symptoms and should not be left untreated. It has been linked to:
- Poor concentration (with negative effects on decision-making ability and short-term memory)
- Irritability
- Sleep disorders and fatigue
- Restricted activities
- Absenteeism from work or school
- Increased risk of motor vehicle accidents and injuries
In addition, untreated allergic rhinitis may increase your risk of:
- Nasal polyposis
- Acute or chronic sinusitis
- Middle ear infections, and Eustachian tube dysfunction
- Sleep apnoea
- Upper respiratory tract infections
- Dental problems (due to excessive mouth breathing)
What are the most common allergens that cause allergic rhinitis?
Aeroallergens (allergens that we breathe in) are the most common cause of allergic rhinitis. For some people, allergic rhinitis symptoms are seasonal. Seasonal allergic rhinitis may be due to pollens from grasses, trees or weeds. For those who experience allergic rhinitis throughout the year, symptoms may be related to dust mites, pet dander, cockroaches or mould.
How is allergic rhinitis treated?
Following blood tests to establish the cause of your allergic rhinitis, you should try to avoid exposure to specific allergens. Saline rinses can help to flush allergens from the nasal passages and can be used as often as needed. Antihistamine tablets may be recommended, as they counteract the histamine released by mast cells during an allergic response.
If the above measures are not sufficient to control allergic rhinitis symptoms, a corticosteroid nasal spray be prescribed. Corticosteroids help to control allergic rhinitis by suppressing the unwanted immune response in your nose.
Immunotherapy (or “desensitisation”) is the closest thing to a “cure” for allergic rhinitis, and may be required when symptoms are severe. Immunotherapy “switches off” an allergy by adjusting the way the body reacts to an allergen. It is given as medication under the tongue, or as a course of injections. It usually takes 6-9 months before immunotherapy relieves allergic rhinitis symptoms, and in most cases, 3-5 years’ ongoing treatment is recommended.