Medical - ~ - Hay fever

Causes of hay fever
Hay fever is caused by breathing in pollen particles and by pollen
getting into the eyes. You can get hay fever at any time from early
spring to late summer, depending on which pollen or pollensyou're
allergic to.
The pollens most likely to cause problems in early spring are those
from trees such as the silver birch, ash, oak and Londonplane.
Grasses pollinate during mid-summer from May to August. The most
profusely pollinating grasses are timothy, rye, cocksfoot, meadow and
fescue.
Occasionally, in late summer and autumn, weeds such as nettles and
dock as well as mugwort and plantain can trigger hay fever.
The condition tends to occur in atopic allergy-prone families and
usually starts in the early teens, with symptoms peaking inthe 20s.
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Symptoms of hay fever
The main symptoms of hay fever are:
*. Repeated sneezing attacks
*. Runny or itchy nose
*. Itchy or watery eyes
*. Itchy throat, palate and ears
*. Loss of concentration
*. General feeling of being unwell (hence 'fever')
If the pollen count is very high, many will also wheeze (so-called hay asthma).
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Hay fever treatments
The most useful treatments for hay fever are:
*. Antihistamine tablets and nasal sprays, which if taken regularly
help torelieve a runny nose, sneezing, an itchy throat and itchy,
watery eyes
*. Anti-inflammatory nasal sprays and nose drops (usually containing
steroids), which reduce inflammation in the delicate lining of the
nose. These should be taken daily for the best results
*. Anti-allergy nasal sprays and eye drops, such as cromoglycate,
which act on the linings of the nose and eyes to stop the allergen
triggering a reaction
*. Decongestant tablets and sprays can help if the nose is blocked and
stuffy, but can lead to rebound blocking
Most of these medicines are available over the counter, but some are
onlyavailable on prescription. You may need to try different
treatments or find a combination that works best for you.
Steroid injections, although effective for symptom control, are
discouraged owing to unwanted side effects such as osteoporosis ,
cataracts and skin thinning.
Homeopathic and herbal treatments are less effective than conventional
therapies. Some experts advocate taking local honey every day for a
few months before the pollen season starts to improve symptoms, but no
studies have been performed to prove this.
If symptoms remain severe despite medication,you may benefit from
desensitisation immunotherapy to grass pollen. This involves
beinggiven tablets or injections containing minute amounts of pollen,
with the dose being increased gradually over a three-year period to
induce immune tolerance and cure the allergy.
Sublingual grass pollen immunotherapy for timothy grass allergy is
available in the UK for people with positive skin prick tests or
specific immunoglobin E (IgE) blood tests to grass pollen.However, it
is expensive and needs to be used oversuccessive hayfever seasons to
become effective, so use may be limited by your local primary care
trust - ask your GP for details. The injection form of immunotherapy
is now only available through specialist clinics as there is a risk of
anaphylactic reaction. No silver birch or tree pollen immunotherapy is
currently available.
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Preventing hay fever
If you have hay fever, there are steps you can take to avoid exposing
yourself to pollen:
*. Keep an eye on the pollen count (often included in weather reports)
and stay inside as much as possible when it's high.
*. Wear wrap-around sunglasses to stop pollengetting in your eyes
*. Saline douches or a little Vaseline applied inside the nose will
reduce symptoms
*. Keep car windows closedand switch on the air conditioning to
prevent pollen entering the car
*. Keep bedroom doors andwindows closed in mid-morning and early
evening when pollen levels peak
*. Avoid areas such as parks or fields, particularly in the early
evening when there's a lot of pollen floating at nose level
*. Get someone else to mow the lawn and don'tlie on freshly cut grass
*. Change into clean clothes when you come home and wash the clothes
you wore outside
You may be able to find out what you're allergic toby having allergy
tests. You can then take practical steps to avoid that particular
pollen.
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Oral allergy syndrome
Some people with hay fever develop oral allergies to certain fruits,
vegetables and nuts. This is also called pollen-food or oral allergy
syndrome (OAS).
People with OAS typically develop hay fever in early spring and notice
itching and swelling of the mouthand throat when they eat fresh fruit
and vegetables. This is due to the food containing a protein similar
to the allergy-provoking protein in the pollen.