Hay fever, sometimes called pollenosis, is a form of allergy. In it, the mucous membrane lining the nose is sensitive to one or more kinds of pollen and, as a result, swells and becomes inflamed. It is an extremely common complaint; it is estimated, for instance, to affect between five and ten per cent of the population of the USA (the only country for which there are official figures).
Doctors define hay fever as a typical allergen- antibody reaction. What basically happens is that, if your genes carry the requisite allergic tendency, your body will develop a substance called reaginic-antibody or IGE. In hay fever, this antibody is to be found in the lining of the nose and bronchial tubes, eyes and skin. When an antigen ? in this case, a pollen - comes into contact with IGE. antibody, a reaction takes place on the surface of the cell and various substances, including histamine, are released. As a result, the surrounding tissue swells full of fluid and there is a watery discharge, with an outpouring of mucus on the surface. In other words, the body reacts as though a powerful infection has arrived, rather than harmless grains of pollen.
Grass pollen is a very common antigen, but all pollens can cause the disease. When the pollen season arrives, you will sneeze almost constantly. Usually, your nose runs like a tap, though it may remain congested and blocked. Your eyes will be sore, red and watery, because pollen grains have got on to the conjunctiva, the transparent "skin" over the eyes. Asthma, or at least mild wheezing, may appear when the pollen season is at its peak
Urticaria - itchy wheals - may crop out on the skin where you have been in contact with grass. Itching inside your ears, on the roof of your mouth and in your throat may be a constant source of irritation. You may well feel generally ill and you can even develop a mild fever.
Diagnosis and treatment
Sensitivity testing is essential for effective treatment. This should be carried out well in advance, as systematic desensitization must be started at least four months before the pollen season begins. You will be tested on one, or both, arms with a range of pollen extracts and probably some other common allergens, such as house dust mite, fungi and horse hair. The most effective method is to make a series of pricks, each of contains about a millionth of a millimetre of allergenic extracts into the skin itself. If a weal develops in a few minutes, you are sensitive to the extract.
Following this, a vaccine, made to suit your sensitivity reactions, is injected in increasing strengths every week until the course is completed. Usually, this must be repeated annually for three years.
Even so, you should avoid potential risk areas. Never walk through long grass or ragweed, keep your bedroom and car windows closed and avoid country holidays in the pollen season. Antihistamine drugs damp down the symptoms, but will make you sleepy, especially with alcohol, and you should not drive while taking them. Decongestant sprays containing ephedrine will make your nose more comfortable, while cortico-steroid eye drops will help your eye symptoms. Anti- asthmatic drugs may also be helpful.