what exactly is hay fever?
Hay fever, seasonal allergic rhinitis (SAR), is an allergic reaction that occurs when the immune system overreacts to substances that have been inhaled. There are two main types of allergic rhinitis, seasonal and persistent. Hay fever is the common term used to describe seasonal allergic rhinitis. SAR is an allergic reaction that is triggered by the airborne pollens of specific seasonal plants such as trees, weeds, mould and, much more commonly, grasses.
Persistent Allergic Rhinitis, which usually occurs all year round, is caused by indoor allergens such as dust mites, dander shed from the coats of household pets, or indoor mould.
Allergic rhinitis affects between 10% and 25% of the worlds population, and this number appears to be increasing.
Symptoms
Rhinitis is inflammation of the mucosal membrane in the nose. Symptoms, which can be mild or severe, include:
- itching of the nose, palate, throat (oropharynx) and ears
- sneezing
- runny nose (rhinorrhoea)
- nasal congestion
Hay fever is often accompanied by conjunctivitis, which is inflammation of the mucosal membrane that lines the exposed portion of the eye. Symptoms of conjunctivitis include irritation, itching and watering of the eye.
Some sufferers may also experience facial pain, headache, loss of concentration and symptoms of asthma, including difficulty breathing, wheezing and tightness in the chest.
The effects of hay fever on quality of life
Many sufferers of hay fever report that their symptoms are not well controlled and, whilst symptoms are not life-threatening, they can have a substantial impact on a persons quality of life and ability to function daily.
Practical problems experienced include:
- continual nose blowing
- eye and nose rubbing
- thirst
- disrupted sleep
- tiredness
- poor concentration
- reduced work productivity
Significant learning impairment in children with hay fever has been demonstrated, an effect that is exacerbated if the child is taking sedating antihistamines. Recently, a link between hay fever and poor GCSE examination performance was also demonstrated. It was shown that young people experiencing hay fever on an examination day were 40% more likely to drop a grade between their practice (mock) and final exams, and 70% more likely to drop a grade if they were taking sedating antihistamines at the time of their examinations.
Hay fever and asthma
Hay fever (seasonal allergic rhinitis) and asthma commonly occur together. An estimated 10% to 50% of patients with seasonal allergic rhinitis also suffer from asthma, and over 80% of patients with asthma experience seasonal allergic rhinitis