Hay fever is one of the most common of the allergic diseases and affects roughly one in four people in the UK. Hay fever causes symptoms such as sneezing, watery eyes and blocked nose and can make life a misery for many, particularly during Spring, Summer and early Autumn. You can suffer from hay fever at any age and allergic reactions are triggered by a wide range of pollen from wind-pollinated trees, grass and weeds.
Hay fever symptoms are caused by protein molecules in pollen grains. The immune system ‘over-reacts’ to these allergens, which it manifests in the form of an allergic reaction. Immune molecules known as Immunoglobulin E are produced and these cause the release of the inflammatory chemical called histamine from mast cells (a type of immune cell). It is histamine that produces the characteristic symptoms of an allergic reaction. A non-allergic person’s immune system will not produce this reaction on exposure to allergens in pollen.
Hay fever is a relatively new disease, first described in 1819. It took nine years to accumulate sufficient hay fever cases to present a paper on this new condition to a medical journal. Now hay fever is much more common, particularly in the UK, which has more cases than anywhere else in the world (followed closely by Ireland, New Zealand, Australia and Canada). Here are the facts:
A person who appears to be suffering hay fever symptoms may, actually, be suffering from:
Perennial rhinitis: In perennial rhinitis, some other allergen, like house dust mite, is involved (symptoms are present all year round but, for some reason, seem worse in the pollen season). To learn more about rhinitis, visit our Rhinitis Information page.
Sinusitis: This is inflammation of the sinus cavities, which are empty spaces within the skull, behind the nose. Sinusitis may be caused by allergy, but it may also be caused by benign growths in the nose called polyps. Acute sinusitis can also result from bacterial infection.
Hay fever is not considered a medically serious allergy, unlike peanut allergy or asthma which can cause potentially fatal attacks. The main impact hay fever has on everyday life is upon the general quality of life. Common effects are:
Students’ academic performance is affected during exams, given that the exam season usually coincides with the height of the pollen season. A study of nearly 2,000 GCSE candidates in the West Midlands found that those who had hay fever were 40% more likely to drop a grade between their mock exams, held earlier in the year, and the formal exam held in the Summer when compared to those who did not have hay fever. Normally, dropping grades between mocks and GCSEs is very unusual. Students often find their mock grade a motivating factor and might be expected to improve on it, or at least do no worse.
There is strong evidence that people living near roads affected by heavy traffic are more likely to become allergic to pollen and have higher than expected rates of hay fever.
If you would like to know more about when the pollen/hay fever seasons begin and end please read our pollen count page.