What is hayfever?
Hay fever is one of the most common allergies, affecting around 25-30% of the US population. The term ‘hay fever’ is misleading, as it is actually a clinical syndrome that can be triggered by a variety of allergens, including pollens and spores from trees, grasses, weeds and molds.
- Symptoms
- Who is affected?
- The triggers
- The role of histamine
- Symptomatic Treatment of Hay Fever
- Self help
- Videos
Symptoms
Symptoms include:
- itchy nose and roof of mouth
- sneezing
- runny nose
- blocked nose
- blocked sinuses
- itchy eyes
- red eyes
- watery eyes
- loss of smell or taste
As a result of a blocked nose, a person may lose their sense of taste and smell, and even develop an itchy throat. Many people may have itchy, red and watery eyes.
An attack of hay fever may last just a few hours, days or even weeks, and can cause considerable distress and inconvenience. Driving may become difficult due to continuous sneezing and watery eyes. Some sufferers may need to take time off work, as hay fever may leave them feeling tired and exhausted. If nasal congestion is severe, sleeping may be interrupted, as breathing may be difficult. Many school children are badly affected, just at the time of the year when they take public examinations.
Who is affected?
Hay fever affects both sexes equally. It can start at any age but peaks in incidence around the age of 20–30 years, decreasing in middle age. In general, after hay fever begins, it worsens over successive years, reaches a peak and remains stable for a number of years, and then declines in severity.
Hay fever has some genetic basis, as you are more likely to suffer if your parents do. Genetics are not, however, the only cause.
Environmental pollution may contribute to the incidence of hay fever. This may, in part, explain why hay fever is on the increase even though pollen counts have been declining over the past 20 years.
The Triggers
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In the US, the main hay fever season lasts from May to August and is linked to the release of pollen. Symptoms that develop in the spring may be triggered by tree pollen, while those in the height of summer are often caused by grasses. Weed and mould spores and pollens cause problems in late summer and early autumn. Many people are allergic to just one type, but those less fortunate may be sensitive to a range and suffer for most of the summer. The hay fever season generally starts later in the north of the country than the south, reflecting the later arrival of the seasons. |
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The severity of symptoms are linked to the daily pollen count. A pollen count of 50 grains per cubic meter is sufficient to trigger symptoms in most hay fever sufferers. Pollen is released early in the day, rises with the warm air and falls again in the evening. Thus, symptoms are generally worse mid-morning and in the early evening when the pollen count is at a peak. |
The Role of Histamine
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The signs and symptoms of hay fever occur within minutes of exposure to the allergen. Usually the first symptom is itching, as histamine stimulates nerves in the eyes and nasal passages.
This may result in sneezing – an attempt to eject the irritating substance. Next, histamine triggers nerves that control the production of watery secretions, to try to wash away the irritant. Finally, histamine has a direct action on the blood vessels in the nose, causing further nasal discharge. The release of histamine and other agents can also result in nasal congestion, and red eyes caused by swelling. Blockage of the nose can be a later complication; however, this is not directly caused by histamine but by other agents. |
Symptomatic Treatment of Hay Fever Symptoms
The treatment of hay fever ranges from non-prescription drugs (typically antihistamines) for mild symptoms to prescription drugs (typically steroid sprays) for severe symptoms . Antihistamines are available as tablets, nose and eye-drops or sprays. You use this medicine partly to prevent your symptoms and partly for relief when your symptoms appear. It is often necessary to combine several of these drugs to avoid symptoms and they only work as long as you continue use them. Symptomatic drugs may remove the symptoms, but your allergy remains.
The use of steroid sprays is increasing and seems to be a more effective treatment for severe symptoms than antihistamines. Steroids are often added to the treatment as antihistamines do not cover all symptoms.
If you do not feel that your allergy is sufficiently helped by the introduction of various avoidance measures, and your need for anti-allergic drugs is considerable, you should consider consulting a specialist about the possibility of vaccination treatment.
Self help
The simplest way to avoid hay fever is to avoid unnecessary exposure to pollen. Some simple precautions can help to reduce the severity of attacks, especially in individuals who are badly affected.
Advice for the hay fever sufferer
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- Keep an eye on pollen counts reported in the media – if high try to avoid staying too long outside
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- Wear glasses or sunglasses when outside
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- Avoid open grassy spaces, especially after they have been freshly mown
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- Keep windows and sunroof shut when driving
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- Use a pollen filter in your car and air conditioning at home
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- Bring in any washing before evening
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- Dust, vacuum and clean your home regularly
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- Splash your eyes with water when you go indoors
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- Try to spend holidays in the mountains or at the coast where pollen counts are low
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- Touch pets as they may carry pollen in their coats
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- Wear clothes containing wool or feather down, as these items may carry pollen
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- Spend time in smoky places, polluted atmospheres or places where chemicals are being used (e.g. paint), as this may aggravate symptoms.
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Videos
While many know what it's like to suffer from hayfever, its actual causes are less widely known. Our panel will discuss why some people get hayfever, and what triggers it. Topics will include:
- What distinguishes hayfever from other allergies?
- What are its symptoms?
- Is there a genetic predisposition to hayfever?
- What happens in your body during a hayfever attack?
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We are far from finding a universal cure for hayfever, but there are things you can do to suffer less. Our panel will explore the most successful strategies. Topics will include:
- How do you get tested for hayfever?
- What should you do when pollen counts are high?
- What over-the-counter and prescription medications are available?
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