What is allergic rhinitis?
Allergic rhinitis, sometimes referred to as having a permanent "head cold", involves a recurrent runny, stuffy, itchy nose and frequent sneezing. The nasal blockage may be one-sided or alternate from one side to the next. Nasal blockage associated with headache, persistent dripping at the back of the throat and bad breath, suggests chronic sinusitis rather than rhinitis.
About 20 per cent of the general population suffer with rhinitis. Of these people, about one third develop problems before the age of 10.
What causes allergic rhinitis?
Up 50 per cent of cases of allergic rhinitis are caused by airborne allergens. There are two main types of allergic rhinitis, perennial allergic rhinitis and seasonal allergic rhinitis.
Perennial allergic rhinitis occurs all year round and the culprits include the house dust mite, animals and moulds. Irritants such as strong perfumes and tobacco smoke can aggravate this condition.
Seasonal allergic rhinitis, also called hay fever, occurs in spring and early summer or even later. It may affect the eyes more than the nose. In the spring and early summer it is usually caused by pollen from trees and grass and spring mould spores. In autumn, it is caused by pollen from weeds and mould spores. In New Zealand the seasons are not very distinct and thus the hay fever season is not very well defined. See our pollen calendar for more information.
Foods do not play as big a role as many people have thought in the past and the importance of foods tends to decline as the child ages.
What are the symptoms?
A person may have any or all of the following:
- watery discharge from the nose all the time, occasionally or during certain seasons of the year
- stuffy nose all the time or during specific seasons
- reddened, pebbly lining in the lower eyelids
- frequent throat-clearing
- breathing through the mouth
- snoring
- rabbit-like movements of the nose
- a horizontal crease across the nose as a result of constant rubbing
- bouts of sneezing, especially in the morning
- repeated nosebleeds
- headaches because of pressure from inside the nose
- frequent earaches, fullness in the ear, ear infections or hearing loss
- dizziness or nausea related to ear problems
- chronic cold without much fever
- nasal voice because of blocked nasal passages
- dark circles under the eyes as a result of pressure from blocked nasal passages on the small blood vessels. Also known as "allergic shiners".
What is causing your allergic rhinitis?
Your doctor will confirm the specific allergens causing your rhinitis by taking a complete symptom history, doing a physical examination, and performing skin prick tests.
How is allergic rhinitis treated?
Reduce contact with the allergen
It is never easy trying to decide on a new home for a pet, but in some cases this might be the best option. Even after you have removed the cat from your home, the allergens remain in furnishings for long periods afterwards and can cause symptoms.
House dust mite reduction measures include mite-proof covers for the mattress, duvet and pillows. Removing items that collect dust from the bedroom will help. A good quality vacuum cleaner with HEPA filter for the exhaust air is essential to ensure that allergen is not disseminated in the atmosphere. Bedding should be washed frequently in water hotter than 55oC. If you do have soft toys, freeze them overnight and air in the sun.
Drugs
Nasal sprays: Some decongestant sprays are used to relieve short duration nasal congestion lasting for less than one week. Prolonged use of these preparations may result in worsening of the nasal congestion. Steroid preparations do not cause worsening with prolonged use. They work best when used in a preventative manner. For example, they may be used for weeks or months at a time during an allergy season. Ask your doctor about the appropriate medication for your condition.
Antihistamines are useful in alleviating some of the symptoms of rhinitis. They are helpful in controlling sneezing, itching and runny noses, but are ineffective in relieving nasal blockage.
Decongestants help to shrink the swollen membranes in the nose, which makes it easier to breathe. Side effects include drowsiness or irritability, and decongestants may interact with other medications such as drugs for thyroid disease, high blood pressure, diabetes, depression or heart disease.
Eyedrops: The eye problems that sometimes occur with allergic rhinitis may not always respond to the above medications. Eyedrops containing decongestants alone or in combination with antihistamine are available for mild to moderate eye problems. Eye irritation is one side effect. Prolonged use of decongestant eye drops can also cause rebound worsening when stopped. Some brands of eye drops can be used preventatively and are safe to use for prolonged periods - ask your doctor for more specific information.
Can allergic rhinitis be 'cured'?
Desensitisation, or immunotherapy, is used to 'turn off' the abnormal response of the immune system to an allergen. It is mainly used to relieve the symptoms of hay fever and allergic asthma to such substances as pollens, moulds, house dust mites, and pets, as well as to control severe reactions to insect stings.
Immunotherapy seems to down-regulate the immunological process that triggers the body's allergic reaction. Symptoms such as runny nose, watery eyes and wheezing are thereby reduced, as is the accompanying inflammatory response that causes persistent symptoms.
To begin, a very dilute dose of the substance you are allergic to is administered by injection once or twice a week. This dose is gradually built up over three to four months on average, until a maintenance dose is achieved. Shots are then given monthly for at least three years.
This method of treatment is the only one that deals with the underlying cause of allergic rhinitis. Not everyone benefits from treatment, however the vast majority of patients show at least some degree of improvement. Ask your allergist about whether you are a good candidate for immunotherapy.
