Hay fever is the bane of many people's lives, causing sore, itchy eyes, a permanently runny or blocked nose, clogged sinuses and, of course, the inability to stop sneezing. The nasal symptoms are also known as allergic rhinitis and the itchy eyes as allergic conjunctivitis.

What is hay fever?

Hay fever is a response to an allergen. If you are an allergic person your immune system has an exaggerated response to dust, moulds, pollen, some foods, dander (skin particles) from animals, and occasionally things such as perfumes. These are called allergens.

Many South Africans find that their hay fever gets better on the Highveld and worse in Cape Town. When you consider that Table Mountain alone has more species of flowering plant than are present in the whole of the British Isles, this is not surprising.

You may find that you only have hay fever in the summer, or that you get it year round. If you are one of the unfortunates who have it year round, you are probably allergic to various animals, pollens, and the little mites that hide in house dust.

Who gets hay fever?

You'll have noticed among your friends that hay fever is a common affliction. In the USA allergies in general are the sixth most common chronic condition.

There is a definite genetic link involved. If you have one parent with allergies then you have a 25 percent chance of having allergies yourself. If both parents are allergic this rises to 66 percent. You are particularly likely to inherit allergic rhinitis.

Among children, boys under 10 are twice as likely as girls to have hay fever. A study from the USA suggests that between five and nine percent of children have allergic rhinitis, so the constant runny nose may not be a cold. Children must first be exposed to a substance before they can become allergic to it. This is known as becoming sensitised to an allergen.

You may have read that people outgrow hay fever. Unfortunately this is just a rumour, although some children do! In fact you can suddenly develop hay fever quite late in life having never knowingly been allergic to anything before.

What causes the symptoms?

When your body encounters an allergen it produces an antibody, called immunoglobulin E (IgE), to fight the allergen. You have cells called basophils in your blood and mast cells in your body tissues which contain histamines (and other substances). The histamines mediate, or act as channels for, the immune response through receptors in your nose, throat and eyes. When an allergen such as pollen enters your body, it attaches to the IgE on the mast cells, which then break apart and release the histamine. The histamine is then carried by the blood to the nose, eyes and throat, where it attaches to the receptors and causes swelling, irritation, inflammation; mucous... you know the story... Hence the drug type antihistamine.

What can you do?

If your hay fever is seasonal, then be prepared! You know that as the stone pines start to shed, your nose is going to run! There are many over-the-counter preparations available to help, but none of them will completely subdue the symptoms. If you're main problem is a runny, or blocked, nose then a topical nasal spray will be all you need. But beware. If you use these continuously you'll find that your nose will block up again, in what is called rebound congestion. There are preparations available on prescription that will, if used daily, prevent the nose from becoming inflamed. Ask your GP.

Eye irritation can also be relieved by drops. The ones that work best tend to sting, so take care. Again, you can get prescription eye drops from your GP which, with regular use, will stop the irritation from occurring.

Antihistamines are tablets that act systemically against the histamines and so suppress the symptoms. Some of these can make you very drowsy, but there are brands which are allowed for use by airline pilots. They need to be awake! Most of these are over the counter preparations, but some are only available on prescription. Ask your pharmacist or GP.

A word of warning

Read the package insert!

No drug is free from side effects and if you are on other medications these can interfere with antihistamines and even nose or eye drops.