However, the distinction is not absolute. You may suffer from pollen-sensitive allergic rhinitis which by definition is seasonal, but live in an area of South Africa in which the pollen season lasts for much of the year, for example the grasslands.

Who gets allergic rhinitis?

Allergic rhinitis is common and the incidence seems to be increasing, with between five and 40 percent of people affected.

It is slightly more common in boys, older children and young adults and in upper socio-economic groups.

Because of geographical and climatic differences in South Africa, the distinction between seasonal and perennial allergic rhinitis varies between regions. For example, in the grasslands around Gauteng, rhinitis caused by grass allergy is almost perennial, while in the coastal regions of KwaZulu-Natal, the Eastern Cape and the Western Cape, seasonal allergic rhinitis in the spring is well defined. However, many people in the Cape suffer from allergic rhinitis throughout the year, and recent fires have resulted in flare-ups as new growth occurs in the burnt areas.

What causes allergies in South Africa?

South Africa has many climates, ranging from Mediterranean, sub-tropical, tropical, semi-desert and desert and areas with summer rainfall. We have 947 indigenous and 115 alien grass species, and grass pollens are important allergens.

House-dust mites are another important allergen, both on the coast and inland.

Other important sources of allergy are dogs, cats, horses, rabbits and rats. Moulds such as the Aspergillus species are also important.

Food allergies are not a common cause of allergic rhinitis.

Irritants can also cause symptoms of rhinitis, namely swimming pool chlorine, smoking and aerosols. Your swimming pool can also be a pollen trap.

Many allergens in South Africa are different from those found in Europe, particularly those from grass pollens, trees and weeds.

Treatment

The most commonly used treatment for allergic rhinitis, and probably the most effective, are nasal steroid sprays. These reduce nearly all symptoms except problems with smell. If you have seasonal allergic rhinitis then you will only need these during the spring, but if your problem is year-round, then you may need to use the spray for longer. These sprays do not work immediately, and need to be used for some weeks before becoming truly effective. Once they have started to work, you can try reducing the dose to see if your symptoms are controlled on a lower dose. Once or twice a year, stop using them to see if you need them continuously if you have perennial allergic rhinitis. There may be times when you need them less than others.

Oral antihistamines are also commonly used, but although these reduce sneezing and itching, they are not as good at decreasing the general blocked-nose feeling. Antihistamine sprays are not usually very effective.

Nasal decongestant sprays relieve the congestion, but do nothing for the other symptoms, and can lead to problems if overused, that is for more than seven to 10 days. They cause a paradoxical blockage of the nose if used chronically, which is difficult to deal with.

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