What is hay fever?
Hay fever is caused by an allergic reaction to pollen. Ideally, our immune system should be programmed to ignore pollen which is otherwise completely harmless. However, in some people, their immune systems make a mistake which leads to our bodies inappropriately reacting to pollen grains in the environment leading to the release of chemicals such as histamine which result in allergic symptoms.
How common is hay fever?
Hay fever affects 10-15% of children and around 25% of adults in the UK. Typically, it develops in later childhood or early adulthood and can last for many years – generally improving as patients head into old age. However, it is possible to develop hay fever as young as 2 or 3 years of age although this is less common.
How long does hay fever last?
How long your hay fever lasts will depend on what the causative allergen is.
- People with an allergy to tree pollen will typically start to develop hay fever symptoms in the UK sometime between late January and early March, with symptoms settling by April time.
- People with allergy to grass pollen, will experience hay fever symptoms starting around April and then peak in May and June before eventually settling down.
What are the symptoms of hay fever?
The classic hay fever symptoms affect the nose and include:
- nasal congestion
- runny nose and
- sneezing together with eye symptoms such as itchiness and soreness.
For many, hay fever symptoms will be mild but for a significant minority, they can have a very real impact on day-to-day life affecting concentration, school performance, sleep and leisure activities. Hay fever is also commonly associated with asthma and sinus issues.
What are the available hay fever treatments?
As with any allergy, the first line of treatment is to try and avoid what you are allergic to but of course this can be very challenging when it comes to pollen. Pollen filters in the car, wraparound sunglasses, saltwater nasal sprays, avoiding drying clothes outside and washing your hair before bedtime (to remove any pollen grains from your hair) can all help.
However, most people with significant symptoms also require some medication. Useful hay fever treatments include:
- over the counter long-acting, non-sedating antihistamines such as Cetirizine or Loratadine
- steroid nasal sprays which can be very safe and effective if used correctly, for those with more significant symptoms
- desensitisation, for those with severe symptoms
What is pollen immunotherapy?
Some of the most exciting developments in the field of allergology are those in the field of desensitisation or immunotherapy, which has the potential to actually cure allergies by diverting the immune system’s response to a specific allergen such as pollen. In the past, this highly effective treatment was considered to be high risk because it involved regular injections that could potentially cause severe reactions. However, new forms of grass and tree pollen immunotherapy are now widely. Treatments are also available for allergy to house dust mite, cat, dog and horse.
Who is pollen immunotherapy suitable for?
Pollen immunotherapy is suitable for:
- Patients who have a firm diagnosis of pollen allergy together with symptoms that are not managed by regular medications such as antihistamines or steroid nasal sprays are usually the best candidates.
- Some people with less severe hay fever who wish to minimise the use of steroid nasal sprays may also prefer this form of treatment.
Sublingual immunotherapy involves using a spray, tablet or drops made out of the problem allergen and it is then administered under the tongue on a daily basis rather than needing to use injections. Immunotherapy by the sublingual route is much safer (with over a billion doses given globally) and thus can be given at home. As well as being shown to reduce the symptoms of rhinitis, there is now scientific evidence to suggest that desensitisation can reduce the risk of developing new allergies and also asthma.
Our team has a particular expertise in sublingual immunotherapy and a long track record of involvement in research as well as extensive clinical experience. Many of the treatments we use are only available in specialist allergy centres.
Professor Adam Fox
Date reviewed: December 2021
Adam Fox is a Professor of Paediatric Allergy with over 20 years experience in both the NHS and private sector. Professor Fox is Commercial Medical Director at Guy’s & St Thomas’ Hospitals NHS Foundation Trust and Professor of Paediatric Allergy at King’s College London and the founding Director of the KCL Allergy Academy, a postgraduate educational programme, which was a finalist at the BMJ Awards in 2018.
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