Why do some people suffer and others not?
You are more likely to suffer from hay fever if members of your family suffer as genetics play a role.
What is the scientific reason for hay fever symptoms? i.e., what happens in the body to cause the problems?
An allergic reaction happens when your body's immune defence mechanism, which is designed to protect against bugs, is over-sensitive. The body's immune system is essentially "trigger happy" so it attacks harmless things like pollen, which in turn causes inflammation and an allergic reaction.
In the case of hay fever, when pollen gets into the nose it triggers irritation, or sneezing, as the body identifies the pollen as harmful. hay fever can lead to an increased asthma risk, too.
People seem to suffer at differing times during the spring, summer and perhaps into the autumn. Why is this?
The reason that people suffer at different times of year is because they are allergic to different types of pollen. In the spring time it's the tree pollen that triggers the reaction. In the summer it's caused by the grass, and in early autumn symptoms are triggered by pollen from weeds.
Can you test to identify which pollens an individual is affected by? What does testing involve?
Yes – there are a couple of different tests. The first is a skin scratch test, which gives immediate results. This type of test is designed to identify the patient's response to particular pollen, or other allergen, and is a safe and easy clinic test.
The allergen is applied to the skin in a localised area and the skin is then pricked to allow a tiny amount to enter the superficial layer of the skin. We can then measure the reaction and prescribe accordingly. Before the appointment people should not take antihistamines for 48 hours as this might affect the test.
Results are ready within 20 minutes, which enables people to be diagnosed and receive advice about managing the condition during the same appointment.
The second type of test commonly used is an IgE-based blood test. Other available blood tests (eg. IgG-based) are not recommended and are harder to interpret. Blood tests tend to give equivalent results, but will allow more allergens to be tested. This test may be preferable for patients who have a lot of eczema and for those who cannot avoid taking antihistamines for 48 hours.
Both of these treatments are available on the NHS and at Spire, The Glen Hospital, Bristol.
Mild symptoms can usually be taken care of with an over-the-counter antihistamine tablet. What advice do you give to people who buy such tablets?
I'd advise people to follow the instructions on over-the-counter medicines and continue to take them to manage symptoms. Nasal sprays with a low dose of steroids can be very effective – there are some useful videos on YouTube that people can refer to for the best technique to use.
What treatments are available to those whose severe reactions requirement "extra" help?
This depends on the patient. Some people may benefit from desensitisation by injection or oral tablets, known as immunotherapy, which helps the majority of people, but not all.
Immunotherapy involves a gradual introduction of the allergen into the body to build up a resistance. It must be supervised by a specialist allergy centre in case of a serious adverse allergic reaction (anaphylaxis).
However, it doesn't work for everyone. Sadly, there's no miracle cure-all for hay fever.
What preventative measures can people take, if any, to guard against hay fever?
At the start of the hay fever season, sufferers should start taking daily antihistamine tablets and using nasal spray. If you suffer very badly, then it's a good preventative measure to use these medicines daily, whether or not you've got symptoms – so from around May until September if you're allergic to grass pollen.
Other ways people can reduce symptoms include wearing sunglasses all day to block the pollen from reaching the eyes.
Clothes and hair are magnets for pollen so after you've been outside, take a few minutes to give your clothes a good shake before you go indoors. Have a shower, wash your hair and change into clean clothes to minimise symptoms once indoors.
Dr Unsworth trained at St Bartholomew's Hospital, University of London, in 1987 and has had an interest in the immune system and disease since then. He lives near The Downs in Stoke Bishop, with his family, including four children, none of whom have any allergies!