Allergic Rhinitis

Overview

Hay fever (allergic rhinitis) is an allergic response to certain substances in the environment. Hay fever is the most common allergic condition and affects ten to fifteen percent of the population.

Seasonal hay fever is a condition in which you may be allergic to pollens released by trees, grasses or weeds. If you have year-round hay fever, you may be sensitive to indoor allergens such as dust mites, mould or pet hair.

How we get hay fever

Those who have hay fever may react to one or more common inhaled allergens. Typically tree pollens which appear in April, grass pollens whose levels are highest in May and July and fungal spores, appearing in September, affect most sufferers.

The allergic reaction occurs because of a process called sensitization. In this process the immune system mistakenly identifies the allergen in question as an invader and produces an antibody against it called immunoglobulin E, or IgE. The next time the body is exposed to the allergen, the immune system launches an allergic reaction. The IgE antibodies trigger the release of inflammatory chemicals such as histamine. This swells the mucous membranes in the nose, sinuses and eyes and causes a runny nose, watery eyes and sneezing.

Symptoms

Normally symptoms of hay fever are more severe in the morning and evening. This is because pollen rises during the day after being released in the morning then settles at night. Sufferers may also find that their condition worsens on windy days as pollen is scattered and a reduction in symptoms when it rains or after rain, as pollen clears. However, people who are allergic to fungal spores normally find their symptoms worsen in damp weather.

Rhinorrhoea

A runny nose is a commonly experienced symptom of allergic rhinitis. The discharge is often thin, clear and watery but can change into a thicker, coloured, purulent one.

Nasal Congestion

The inflammatory response caused by the allergen makes the blood vessels in the nose widen and this results in nasal congestion. Severe congestion may result in headache and occasionally earache.

Nasal and soft palate itching

This commonly occurs. Itching is sometimes experienced on the roof of the mouth.

Eye symptoms

The eye may be itchy and watery. It is thought that these symptoms are a result of tear duct congestion and also a direct effect of pollen grains being caught in the eye, setting off a local response that causes inflammation. Irritation of the nose by pollen probably contributes to eye symptoms too.

Sneezing

In hay fever, the allergic response usually starts with symptoms of sneezing, then rhinorrhoea, progressing to nasal congestion.

Risk Factors

Any of the following risk factors may increase your risk of developing hay fever:

Age

The average onset of allergic rhinitis is around ten. Of those who develop allergic rhinitis about eighty percent do so before the age of thirty. The condition tends to diminish as a person ages possibly because the immune system becomes less responsive. There are those who develop allergic rhinitis beyond age thirty, and their condition does not diminish with age.

Family history of allergies

Family history is an important factor. If one parent has allergies the chance of a child developing them is thirty to fifty percent. When both parents have allergies the chances of the child developing them increase to sixty to eighty percent.

Male sex

In children males are more affected than females. In adults both sexes are affected equally.

First born status

First born children are more likely to develop allergies. This is because it is thought that first born babies have higher levels of the key immune protein, immunoglobulin E (IgE), which is associated with allergies.

Exposure to cigarette smoke in the first year of life

The allergic process and production of antibodies immunoglobulin E (that is then responsible for triggering the inflammatory response seen in hay fever) begins in a baby’s first year. Smoking increases the risk of such allergic processes.

Exposure to indoor allergens such as pet hair

The more allergens that a baby or person is in contact with the more likely they are to exhibit inflammatory responses against such allergens, as the body has produced antibodies in response to the contact with the allergens.

Complications

By itself, hay fever can impair your quality of life. Congestion and constant nose blowing can cause discomfort and social embarrassment. The resulting sleeplessness, fatigue and irritability can also affect your performance at work or school.

Asthma

Hay fever may increase your risk of developing more serious allergic conditions such as asthma, a chronic condition that occurs when the main air passages of your lungs, the bronchial tubes, become inflamed. Hay fever and asthma often occur together. If you have asthma, you may have symptoms such as difficulty breathing, shortness of breath, a tight feeling in the chest, coughing and wheezing.

Sinusitis

Prolonged sinus congestion due to hay fever may increase your susceptibility to sinusitis which is a bacterial infection of the membrane that lines the sinuses. Sinusitis causes pain, tenderness and swelling around your eyes, cheeks, nose or forehead and can be either acute or chronic.

Middle ear infection

In children, hay fever often is a contributing factor to middle ear infection (otitis media), which causes pain, fever and fluid build up in the middle ear.

When to seek medical advice

If you experience occasional symptoms of hay fever and haven’t found relief from using over-the-counter medications, see your doctor to discuss a treatment programme. Also see your doctor if your symptoms are persistent or if you experience side effects from over-the-counter medications.

Treatment

As hay fever is an immune response the products used to treat the condition cannot cure it but can only assist in reducing symptoms. Those available include antihistamine tablets or liquids, nasal sprays and eye drops. The products used for each individual depends on the symptoms they are experiencing. It is important if you are a hay fever sufferer to start using these products at the first sign of symptoms. If symptoms are left without treatment the immune response will cause congestion and inflammatory symptoms which will then become difficult to treat.

Many over-the-counter preparations are not suitable for those who are pregnant or for children under two years of age and may not be suitable for other individuals, so it is always important to talk to your pharmacist when buying preparation for hay fever or other allergies over-the-counter.

Antihistamines (e.g. cetirizine, loratidine, astemizole, acrivastine)

Neutralise the chemical histamine, which is released when the body reacts to pollen, or has a similar allergic reaction. Therefore even though the body is reacting in an allergic way symptoms will be less severe. Tablet and liquid antihistamines can be used for occasional symptoms, as they start working within about half an hour. So, for those who only experience symptoms when the pollen count is high, antihistamines could be taken on those days that high pollen counts are predicted. However, for symptoms that occur regularly they are best used on a regular basis as a preventative, starting at the first sign of any symptoms. They can be used together with any of the other three groups of hay fever products, where one product is not enough to relieve the symptoms.

Other older antihistamines (e.g. diphenhydramine, chlorpheniramine, promethazine, clemastine) can also be used but tend to have a sedative effect, so are not suitable for use if you are driving or operating machinery. They are therefore less popular.

Antihistamines have teratogenic effects and should therefore never be used in pregnancy. They are also unsuitable for some other people so always discuss your medication and current health problems with a pharmacist before purchasing them.

Nasal sprays

Decongestant (e.g. oxymetazoline, xylometazoline)

These will give short-term relief from nasal congestion. Use of decongestant drops and sprays should be restricted to seven to ten days as prolonged use may cause rebound congestion of the nasal membranes. They are therefore not the most appropriate treatment in a condition which may cause nasal congestion all year round. Oral decongestants (e.g. pseudoephedrine) however may be helpful to reduce congestion that is built-up in a person whose symptoms have not been controlled with an antihistamine or steroid nasal spray.

Steroid (e.g. fluticasone, beclamethasone)

These are particularly effective where there is nasal congestion, where the lining of the nose is swollen, resulting in a blocked nose. Steroid contents of such sprays are very low and very little is absorbed into the body generally, so nasal sprays do not cause side-effects that a steroid tablet can. Although these medications can be immediately effective, relief of nasal congestion may not be seen until the product has been used for days, or even weeks. Steroid nasal sprays should be used throughout the hay fever season but should not continuously for longer than three months without consulting a doctor.

Sodium Cromoglycate

This helps relieve hay fever symptoms by preventing the release of histamine. It is most effective when started before symptoms develop and sometimes must be used three or four times a day, throughout the hay fever season.
Eye drops

Antihistamine (e.g. antazoline)

These give immediate and short term relief from the itchy and swollen eyes. They work by neutralising the chemical histamine, which is released when the eye reacts to pollen. They may also contain a vasoconstrictor (e.g. xylometazoline or oxymetazoline) which is effective in reducing the redness of an irritated eye.

Sodium Cromoglycate

As for nasal sprays this helps the eye symptoms of hay fever by preventing histamine release. Again, it is most effective when started before symptoms develop and must be used three or four times a day throughout the hay fever season.

Brand name of preparations available and their ingredients

Oral antihistamines

Zirtek tablets and liquid (suitable for use in children over two years)

Histek tablets contain the antihistamine cetirizine. This is a “new generation” antihistamine and is therefore less likely to cause drowsiness.