Hay fever is a type of allergic rhinitis (inflammation of the nose) caused by the allergen 'pollen' with symptoms including sneezing, runny nose, cough and itchy, red or watery eyes
Hay fever is also referred to as seasonal allergy as sufferers symptoms are likely to be worse from early spring to late AutumnOverview
see also: Sinusitis - A Guide
The symptoms of hay fever are caused when a person has an allergic reaction to pollen. Pollen is a fine powder released by plants as part of their reproductive cycle. Pollen contains proteins that can cause the nose, eyes, throat and sinuses (small air-filled cavities behind your cheekbones and forehead) to become swollen, irritated and inflamed. You can have an allergy to:
- tree pollen, released during spring
- grass pollen, released during the end of spring and beginning of summer
- weed pollen, released any time from early spring to late autumn.
Many people find that their symptoms improve as they get older. Around half of people report some improvement in symptoms after several years. In around 10%-20% of people symptoms go away completely.
There is currently no cure for hay fever but most people are able to relieve symptoms with treatment, at least to a certain extent.
In an ideal world, the most effective way to control hay fever would be to avoid exposure to pollen. However, it's very difficult to avoid pollen, particularly during the summer months when you want to spend more time outdoors.
John Bostock, a Liverpool-born London doctor, had spent his academic career looking at bodily fluids, taking a particular interest in bile and urine. Yet he had also suffered from catarrh - blockages of the sinus and a general feeling of heaviness and tiredness - in June every year since the age of eight. The timing had long perplexed him.
In 1819, aged 46, he presented a study to the Medical and Chirurgical Society called Case of a Periodical Affection of the Eyes and Chest. It described a patient called "JB", a man "of a spare and rather delicate habit". It was an article about himself.
Bostock laid out the symptoms still besetting hay fever sufferers today and some of the treatments he had tried to relieve his agony. They included bleeding, cold baths, taking opium and self-induced vomiting. Nothing had worked. (source: BBC News magazine)
Hay fever symptoms vary in severity and may be worse some years than others, depending on the weather conditions and the pollen count. The time of year your symptoms start depends on the types of pollen you're allergic to.
The symptoms of hay fever include:
- frequent sneezing
- runny or blocked nose
- itchy, red or watery eyes (also known as allergic conjunctivitis)
- an itchy throat, mouth, nose and ears
- cough, caused by postnasal drip (mucus dripping down the throat from the back of the nose)
Less commonly, you may experience:
- the loss of your sense of smell
- facial pain (caused by blocked sinuses)
- tiredness and fatigue
While symptoms of hay fever may be mild, they can interfere with your sleep and your daily activities at school or work.
Hay fever and asthma
If you have asthma, your asthma symptoms may get worse when you have hay fever. Sometimes, asthma symptoms only occur when you have hay fever.
These symptoms include:
- tight chest
- shortness of breath
Hay fever symptoms are likely to be worse if the pollen count is high. The pollen count is the number of grains of pollen in one cubic metre of air.
Air samples are collected in traps set on buildings two or three storeys high. Taking samples from this height gives a better indication of the pollen in the air.
Traps on the ground would only collect pollen from nearby trees and plants.
The air is sucked into the trap and the grains of pollen are collected on either sticky tape or microscope slides (glass plates). The pollen is then counted. Samples are normally taken every two hours, and usually the results are averaged over a 24-hour period.
The pollen forecast is usually given as:
- low: fewer than 30 grains of pollen in every cubic metre of air
- moderate: 30-49 grains of pollen in every cubic metre of air
- high: 50-149 grains of pollen in every cubic metre of air
- very high: 150 or more grains of pollen in every cubic metre of air
Hay fever symptoms usually begin when the pollen count is over 50. The pollen count is usually given as part of the weather forecast during the spring and summer months.
When to seek medical advice
Most cases of hay fever can be treated using over-the-counter medication.
A pharmacist can advise on treatments for you or your children.
You would normally only need to see your GP if:
- you can't control your symptoms with over-the-counter medications or you are having troublesome side effects caused by the medication
- you are experiencing persistent complications of hay fever, such as worsening of asthma or repeated episodes of sinusitis
- the pattern of your symptoms is unusual; such as occurring during the winter or only at your workplace – it is likely that another substance other than pollen is responsible and further testing will be required to confirm this
When you have an allergic reaction, your body overreacts to something it perceives as a threat. In hay fever, the allergen (the substance you are allergic to) is pollen. Your immune system (the body’s natural defence system) starts to respond as if it were being attacked by a virus.
Your immune system will release a number of chemicals designed to prevent the spread of what it wrongly perceives as an infection.
These chemicals then cause the symptoms of the allergic reaction, such as watering eyes and a runny nose.
It's unclear what causes the immune system to do this but there are several risk factors that can increase your risk of hay fever.
- having asthma or another allergic condition such as eczema (an allergic skin condition)
- having a family history of hay fever
- being exposed to tobacco smoke during early childhood
What are you allergic to?
In England, most people with hay fever are allergic to grass pollen. However, trees and weeds can also cause hay fever. Research suggests that pollution, such as cigarette smoke or car exhaust fumes, can make allergies worse.
There are around 30 types of pollen that could cause your hay fever. The pollen that causes hay fever could come from sources including:
- grass – 90% of people in Britain with hay fever are allergic to grass pollen
- trees – about 25% of people in Britain with hay fever are allergic to pollen from trees, including oak, ash, cedar and birch (people with an allergy to birch often also experience an allergic reaction to apples, peaches, plums and cherries as these types of fruit contain a similar protein to birch pollen)
- weeds – such as dock, mugwort and nettles
It's possible to be allergic to more than one type of pollen.
When is there most pollen?
Different trees and plants produce their pollen at different times of the year. Depending on which pollen you are allergic to, you may experience your hay fever symptoms at different times. In the UK, the pollen count season is usually separated into three periods:
- tree pollen – late March to mid-May
- grass pollen – mid-May to July
- weed pollen – end of June to September
However, the pollen count season can sometimes begin as early as January, or end in November.
The effect of the weather
The amount of sunshine, rain or wind affects how much pollen plants release and how much the pollen is spread around. On humid and windy days, pollen spreads easily. On rainy days, pollen may be cleared from the air, causing pollen levels to fall.
During their pollen season, plants release pollen early in the morning. As the day gets warmer and more flowers open, pollen levels rise. On sunny days, the pollen count is highest in the early evening.
Your GP should be able to diagnose hay fever from a description of your symptoms. In some cases, you may be referred for allergy testing.
A diagnosis for hay fever would usually only be required:
- if your symptoms were particularly severe
- the pattern of symptoms was unusual, such as having symptoms during the winter or while indoors
- you experienced complications of hay fever
If possible, keep a diary of what times of the day or year you experience your symptoms, as this can help with the diagnosis.
Your GP may refer you to an immunologist for an allergy test if you have hay fever symptoms all year round (persistent allergic rhinitis), or symptoms that are not responding to treatment. Other substances could be causing your allergy, such as house-dust mites, animals or certain foods.
The two main allergy tests are:
- a skin prick test
- a blood test
Skin prick test
An immunologist will place the allergen on your arm and prick the surface of your skin with a needle. This will introduce the allergen to your blood stream and, if you are allergic to it, you should have a reaction.
If your skin starts to go red around where it was pricked, swells up or becomes itchy, this could be an allergic reaction and would confirm that you have hay fever.
A skin prick test may not be suitable if:
- you are on certain medications, for example antihistamines (see below), which will stop you having an allergic reaction
- you have significant eczema, as your skin may already be red or itchy, so an allergic reaction will not be noticeable
In this case, a blood test may be necessary to confirm your diagnosis (see below).
The use of commercial allergy testing kits is not recommended. The testing is often of a lower standard than that provided by the NHS or accredited private clinics. Also, it is important that the results of the test are interpreted by a qualified professional who has detailed knowledge of your symptoms and medical history.
A sample of blood will be taken from a vein in your arm and tested for the presence of the Immunoglobulin E (IgE) antibody.
If you have hay fever, your body produces this antibody when it comes into contact with pollen. If your blood test is positive for IgE, this may confirm that you have hay fever.
Skin prick testing is usually the first test recommended for people with a suspected undiagnosed allergy
Before visiting your GP, you could first visit your pharmacist and try treating your symptoms with over-the-counter medications, such as antihistamines.
If these fail to improve your symptoms, make an appointment to see your GP as you may need treatment with prescription medications such as steroid medication (corticosteroids).
Below are some of the different treatments you may be offered. Information about a specific medication can be found in the hayfever medicines guide.
Antihistamines treat hay fever by blocking the action of the chemical histamine, which the body releases when it thinks it is under attack from an allergen. This prevents the symptoms of the allergic reaction from occurring.
Antihistamines are usually effective at treating itching, sneezing and watery eyes, but they may not help with clearing a blocked nose.
They are available in tablet form and also as nasal sprays.
You can use antihistamines:
- as an "as-required" treatment – where you take them when you first notice that you are developing the symptoms of hay fever
- as a preventative treatment – for example, if you know there is going to be a high pollen count, you can take them before leaving the house in the morning
Unlike older antihistamines, these newer types shouldn't cause drowsiness, although this can occasionally occur in some people.
If this does happen to you then avoid driving or using tools or machinery. Also contact your pharmacist or GP as there may be an alternative antihistamine you can take.
Corticosteroid nasal sprays and drops
Corticosteroids (steroids) are used to treat hay fever because they have an anti-inflammatory effect.
When the pollen triggers your allergic reaction, the inside of your nose becomes inflamed.
Corticosteroids can reduce this inflammation and prevent the symptoms of hay fever.
Your GP may prescribe corticosteroid nasal sprays or drops instead of antihistamines if:
- you have persistent hay fever that does not respond to antihistamines
- your main symptom is a blocked nose
- you are pregnant or breastfeeding
Corticosteroids are more effective than antihistamine tablets at preventing and relieving nasal symptoms, including sneezing and congestion. They can also relieve itchy, watery eyes. They are most effective if you start using them a couple of weeks before your symptoms usually begin, and work best when used regularly.
It's important that you carefully read the instructions that come with your medication as applying the drops or the spray incorrectly can increase your risk of side effects, such as:
- irritation and dryness of your nose
- nose bleed
- unpleasant taste in your mouth
- itchy skin rash around the nose
If you require rapid short-term relief from severe symptoms (for example if you had an exam or driving test coming up), your GP may prescribe a course of corticosteroid tablets.
The use of corticosteroids for longer than 10 days is not recommended, as the longer you take steroid tablets the more likely it is you will begin to experience unpleasant side effects, such as:
- weight gain
- changes in mood, such as feeling irritable
Hay fever can cause a blocked nose. A decongestant, in the form of a nasal spray, can relieve this. Decongestants reduce the swelling of the blood vessels in your nose, which opens your nasal passage and makes breathing easier.
Your GP can prescribe a nasal decongestant, but there are many available from your pharmacist. Check the ingredients as some decongestants also contain antihistamine. If they do, they may relieve other symptoms as well.
If not, the decongestant will only relieve your blocked nose.
Nasal decongestants shouldn't be used for longer than seven days. They may cause dryness and irritation in your nasal passage, and can make the symptoms of congestion worse (this is known as rebound congestion).
Eye drops are available from your pharmacist to treat the hay fever symptoms that affect your eyes, such as redness, itchiness and watering (allergic conjunctivitis). These drops contain antihistamine to reduce the inflammation in your eyes, which will relieve the symptoms.
Eye drops containing the active ingredient sodium cromoglicate are the most widely used. Check the patient information leaflet for the correct way to use them. Some may cause side effects, such as a stinging or burning feeling in your eyes.
If you have persistent hay fever symptoms that are not relieved by the above treatments, your GP may refer you for immunotherapy treatment. This involves gradually introducing you to small amounts of the allergen (the substance you are allergic to), such as pollen, and monitoring your allergic reaction.
However, this treatment is only carried out in specialist medical centres in case a serious allergic reaction (anaphylaxis) occurs.
The allergen can be given to you as:
- an injection into your skin – this is known as systemic injection immunotherapy (SIT)
- a tablet that dissolves under your tongue – this is known as sublingual immunotherapy (SLIT)
You will then be monitored for up to an hour.
Further doses of sublingual immunotherapy can safely be administered at home after an initial dose has been given under medical supervision.
As you get used to the allergen, the amount used is slowly increased and your allergic reaction to it should get less severe and you should slowly build up an immunity to it.
This can improve people’s tolerance of the allergen, improve their quality of life and has long-term results.
However, immunotherapy may take months or even years to be effective.Top
Hay fever can lead to complications such as sinusitis and middle ear infections (otitis media). Hay fever can also have a significant impact on your daily activities.
In one study, a third of adults with hay fever reported that their symptoms had a considerable negative impact on their work, home and social life.
Children's symptoms can disrupt their schooling and lead to delays in learning and development.
In most cases, the negative impact can be reduced by receiving effective treatment. If you are concerned that hay fever is becoming more and more of a problem in your (or your child’s) life then contact your GP.
Infection of the sinuses (small, air-filled cavities behind your cheekbones and forehead) is a complication of hay fever.
This is called sinusitis and can cause pain and tenderness in the face (near the affected sinuses). You may experience a throbbing pain that is worse when you move your head, and toothache or pain in your jaw when you eat.
The swelling of the nasal passages that happens in hay fever can prevent mucus from draining out of the sinuses. This can make them more vulnerable to infection.
Sinusitis can usually be treated using over-the-counter painkillers. If symptoms persist then antibiotics and corticosteroid tablets or sprays may be required.
Middle ear infection (otitis media)
Hay fever can lead to a middle ear infection if the Eustachian tube (a thin tube that runs from the middle ear to the back of the nose) becomes blocked by a build up of mucus.
This is more common in children as their Eustachian tube is smaller than an adult's.
Most middle ear infections will clear up within 72 hours without the need for treatment. Further treatment is usually only necessary if ear infections keep on occurring.
It is very difficult to completely avoid pollen. However, reducing your exposure to the substances that trigger your hay fever should ease your symptoms.
If possible, try to stay indoors when the pollen count is high (over 50). The following tips may help reduce your exposure to pollen:
- Keep windows and doors shut in the house. If it gets too warm, draw the curtains to keep out the sun and keep the temperature down.
- Don't keep fresh flowers in the house.
- Vacuum regularly, ideally using a machine with a HEPA (high-efficiency particle arresting) filter.
- Damp dust regularly. Dusting with a wet cloth, rather than a dry one, will collect the dust and stop any pollen from being spread around.
- Keep pets out of the house during the hay fever season. If your pet does come indoors, wash them regularly to remove any pollen from their fur.
- Don't smoke or let other people smoke in your house. Smoking and breathing in other people's smoke will irritate the lining of your nose, eyes, throat and airways, and can make your symptoms worse.
- If possible, avoid drying clothes outside. This will help prevent bringing pollen into your house.
Avoiding pollen outside
If you need to go outside or are travelling, the following tips may help reduce your exposure to pollen:
- Avoid cutting grass, playing or walking in grassy areas and camping – particularly in the early morning, evening and at night when pollen counts are highest.
- Wear wraparound sunglasses to stop pollen getting in your eyes.
- Change your clothes and take a shower after being outdoors to remove the pollen on your body.
- Keep car windows closed. You can buy a pollen filter for the air vents in your car. This will need to be changed every time the car is serviced.
Rubbing a small amount of Vaseline inside your lower nostrils can help prevent pollen from entering your nasal passages.
Source - www.nhs.uk