Hay fever and allergic rhinitis
Hay fever is one of the most common allergic conditions. Most people who suffer from hay fever are under 40, and the condition gradually decreases with age.

There are practical things you can do to avoid unnecessary exposure to pollens. And there are many treatment options available, including tablets, nose drops and sprays, and eye drops.

Some people become sensitive to substances they come into contact with (allergens) and suffer symptoms like wheezing, sneezing and itchy eyes. Allergens such as grass and tree pollens are only around for short periods and produce seasonal symptoms (hay fever). Others - such as house dust mite - never disappear, and produce year-round (perennial) symptoms.

Hay fever, asthma and eczema are all related allergy-based conditions and the tendency to develop them runs in families. People with hay fever often have a close relative with one or other of these conditions.

When someone with hay fever comes into contact with allergens, their body produces increased amounts of immunoglobulin E (IgE), a type of antibody. IgE binds to certain cells throughout the body and activates them to release the chemical histamine. This chemical is responsible for the symptoms of sneezing, stuffy nose (rhinitis) and itchy eyes and throat. Most people suffer only a few weeks of mild discomfort, but for an unlucky few, the symptoms can be severe and last for months.

Hay fever can make asthma worse, and some people who are not usually asthmatic may become wheezy.

Most people with hay fever are allergic to grass and oilseed rape pollens, which appear from April to August each year. People who are sensitive to pollen from the trees hazel, yew, elm and alder may develop symptoms from January to April, and people with nettle allergy symptoms can be affected from April to mid-September.
Allergic rhinitis
If you have symptoms like those of hay fever but you have them after the hay fever season is over, they are likely to be due to an allergen that is present throughout the year. This is called perennial allergic rhinitis.

House dust mite is a common cause, but there are others, including allergens from animals such as cats, dogs, and horses. Certain foods, drugs and chemicals can also be involved.

If you suffer from rhinitis all year round, you may want to have tests done to find out what allergens you are sensitive to. Ask your GP whether these are available locally.
Avoiding allergens
Once you have discovered what you are allergic to, the first step is to avoid those allergens as much as possible. For people with hay fever, this means closing doors and windows (including car windows and sunroofs) when the pollen count is high, and avoiding gardening. Close-fitting sunglasses sometimes help, too.

If you are allergic to house-dust mite, simple measures such as vacuuming bedroom carpets, the bed sheets and the mattress may help. You should remove anything likely to harbour dust (such as rugs or soft toys) from the bedroom, and keep your home well-humidified. There's little scientific evidence to suggest that filters, air sprays and special shampoos can help, but dust-proof covers may do so.
Even if you take all the steps you can to avoid the allergens you are sensitive to, you can't normally avoid it altogether, and there is a wide range of treatments to help with the symptoms. You may need to use a combination of treatments for the different symptoms. Many treatments are available over the counter from pharmacists. However, if they don't work, there are other treatments which your doctor can prescribe.

Nose sprays and drops
Nose sprays can help control stuffiness and sneezing. They include steroid-based ones, such as beclometasone (Beconase), and anti-histamines, such as azelastine (Rhinolast). These are available on prescription. Nasal decongestants can be helpful for occasional use, but continued use can, itself, cause congestion.

Eye drops containing the anti-inflammatory sodium chromoglycate (eg Opticrom) can help to prevent itchy eyes.

Antihistamine tablets help to control allergy symptoms. They can be bought over the counter or prescribed by your GP. The newer, non-sedating antihistamines, such as cetirizine (Zirtac) or loratadine (Claratyn or Boots Hay Fever and Allergy Treatment) are now more popular than the older preparations such as chlorpheniramine (Piriton).
Treating severe cases
If you have severe hay fever, medication from a pharmacist may not be enough to deal with the symptoms. Or you may need fast relief (for example, if you have to sit an exam). In these cases, you may need a prescription-only steroid treatment taken as tablets or injection. These are not suitable for everyone, as there are a number of important possible side-effects.
'Curing' an allergy
If none of the drugs available can properly help you control the symptoms of hay fever or allergic rhinitis, immunotherapy is an option. This aims to make you immune to the allergen, and consists of a series of allergen injections, increasing in strength each time.

Immunotherapy is specialist treatment that is only available in appropriately-equipped clinics or hospitals.
Further information
British Society for Allergy and Clinical Immunology.

American Academy of Allergy Asthma & Immunology
Healthwise (Health Information Resource Centre)
Tel : (852) 2849 2400
Fax : (852) 2849 2900
Email : info@healthwise.org.hk
Homepage : http://www.healthwise.org.hk/

This leaflet is for information only. For a detailed opinion or personal advice, please consult with your own doctor
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