Spring can trigger allergic reactions
Spring is very much in the air, and for many people that means hay fever season.
Rhinitis is the name given to inflammation of the nasal passage lining, and allergic rhinitis is where that inflammation is caused by a reaction to common particles in the environment. Hay fever is the common name for those reactions when they are caused by seasonal allergens such as plant pollens.
About 20 per cent of New Zealanders suffer from allergic rhinitis. Whilst it can develop at any time of life, about one-third of sufferers first develop symptoms in childhood, usually before the age of 10.
Symptoms include a recurrent runny, stuffy, itchy nose, and sneezing. The eyes, throat and ears may also be itchy. Treatment can include avoiding allergens, medications (including nasal sprays and tablets) and immunotherapy.
People with allergic rhinitis react to common particles in their environment, such as pollen, dust, mould or animals. Some people are susceptible to only one or two allergens, or triggers, but others are sensitive to many.
When a person inhales the allergen that they are allergic to, antibodies react to it. The chemical histamine is released, causing the inflammation and symptoms characteristic of the condition.
The two main types of allergic rhinitis are perennial and seasonal. Perennial occurs year-round, and includes reactions to allergens such as house dust, animal dander (hair, fur, feathers) and moulds. It is commonly aggravated by tobacco smoke, perfumes and air pollution.
Seasonal allergic rhinitis, often called hay fever, most commonly occurs during spring, early summer and autumn. It is usually caused by different types of pollens from trees and grasses, as well as mould spores.
It is not known why some people are more susceptible than others to the allergens, but anyone who has other allergies, such as eczema (atopic dermatitis) or asthma, or who has relatives with allergies, is more likely to suffer from the condition. Living or working in an environment that constantly exposes a person to allergens can also increase the risk of developing hay fever.
The symptoms of allergic rhinitis are similar to those of the common cold, but may last longer and are seasonal in occurrence. Symptoms include stuffy or running nose, frequent sneezing, itchy eyes, nose, roof of the mouth or throat, coughing, watery eyes, blocked nose, pressure in the nose and cheeks, ear fullness and popping, dizziness and/or nausea, dark circles under the eyes, headache, earache, snoring and nose bleeds.
A doctor will try to establish whether the reaction is perennial or seasonal. They may ask when the symptoms occur and when they are most severe. It may be advisable to keep a diary, noting when the reaction occurred. An examination of the nasal passages may be performed, and blood tested for the presence of antibodies.
If allergic rhinitis causes significant interference to daily life, the doctor may refer the patient to an allergy specialist (allergist). They are likely to perform a series of skin prick tests to determine which allergens cause the most sensitivity.
Treatment is aimed at minimising inflammation and reducing symptoms. This may be achieved by avoiding allergens, with medications or with immunotherapy.
Minimising or avoiding contact with problem allergens can be effective in minimising symptoms. Tips for avoiding allergens include:
■ Pollen — avoid open grassy areas, particularly in the evenings and on windy days, use a pollen filter in your car, keep doors and windows closed, wear sunglasses, use air conditioning, be aware of pollen counts and stay indoors when counts are high.
■ Household dust mites — remove items that collect dust, use an efficient vacuum cleaner fitted with a HEPA filter, wash bedding frequently in hot water, use dust mite covers on mattresses and pillows.
■ Animals — do not keep pets. If pets are kept, keep them outside and wash them regularly. ■ Other allergens — avoid smoky environments and perfumes