Allergic rhinitis

Allergic rhinitis


Allergic rhinitis is inflammation of the inside of the nose caused by an allergen, such as pollen, dust, mould or flakes of skin from certain animals.

It’s a very common condition, estimated to affect around one in every five people in the UK.

Signs and symptoms

Allergic rhinitis typically causes cold-like symptoms, such as sneezing, itchiness and a blocked or runny nose. These symptoms usually start soon after being exposed to an allergen.

Some people only get allergic rhinitis for a few months at a time because they are sensitive to seasonal allergens, such as tree or grass pollen. Other people get allergic rhinitis all year round.

Most people with allergic rhinitis have mild symptoms that can be easily and effectively treated. However, for some, symptoms can be severe and persistent, causing sleep problems and interfering with everyday life.

The symptoms of allergic rhinitis do occasionally improve with time, but this can take many years and it is unlikely that the condition will ever disappear completely.

When to see your GP

You should visit your GP if the symptoms of allergic rhinitis are disrupting your sleep, impairing your ability to carry out everyday activities or adversely affecting your performance at work or school.

Your GP will usually be able to diagnose allergic rhinitis based on your symptoms and any possible triggers you may have noticed. If the exact cause of your allergic rhinitis is uncertain, you may be referred for allergy testing.

Read more about diagnosing allergic rhinitis.

What causes allergic rhinitis?

Allergic rhinitis is caused by the immune system reacting to an allergen as if it were harmful.

This results in cells releasing a number of chemicals that cause the mucus membrane (the inside layer of your nose) to become swollen and excessive levels of mucus to be produced.

Common allergens that cause allergic rhinitis include pollen (this type of allergic rhinitis is known as hay fever), mould spores, house dust mites and flakes of skin or droplets of urine or saliva from certain animals.

Read more about the causes of allergic rhinitis.

Treating and preventing allergic rhinitis

Although it is difficult to completely avoid potential allergens, taking steps to reduce your exposure to a particular allergen that you know or suspect is triggering your allergic rhinitis can help improve your symptoms.

If your condition is mild, you can also help reduce the symptoms yourself by taking over-the-counter medications – such as non-sedating antihistamines or decongestants – and by regularly rinsing your nasal passages with salt water solution to keep your nose free of irritants.

See your GP for advice if you have tried these self-help measures and they haven’t helped. Your GP may choose to prescribe a stronger medication, such as a nasal spray containing corticosteroids.

Read more about treating allergic rhinitis and preventing allergic rhinitis.

Further problems

In some cases, allergic rhinitis can lead to complications. These include:

  • nasal polyps – abnormal but benign (non-cancerous) sacs of fluid that grow inside the nasal passages and sinuses
  • sinusitis – an infection caused by nasal inflammation and swelling that prevents mucus draining from the sinuses
  • middle ear infections – infection of part of the ear located directly behind the eardrum

These problems can often be treated with medication, although surgery is sometimes needed in severe or long-term cases.

Read more about the complications of allergic rhinitis.

Causes of allergic rhinitis

Allergic rhinitis is caused by an allergic reaction to an allergen, such as pollen, dust and certain animals.

Oversensitive immune system

In cases of allergic rhinitis, the immune system (the body’s natural defence against infection and illness) reacts to an allergen as if it were harmful.

If your immune system is oversensitive, it will react to allergens by producing antibodies to fight them off. Antibodies are special proteins in the blood that are usually produced to fight viruses and infections.

Allergic reactions do not occur the first time you come into contact with an allergen. The immune system has to recognise and ‘memorise’ it before producing antibodies to fight it. This process is known as sensitisation.

After you develop sensitivity to an allergen, whenever it comes into contact with the inside of your nose and throat, it will be detected by antibodies called immunoglobulin E (IgE).

These cause cells to release a number of chemicals, including histamine, which can lead to swelling of the mucus membrane (the inside layer of your nose) and the production of excess mucus. This is what causes the typical symptoms of sneezing and a blocked or runny nose.

Common allergens

Allergic rhinitis is triggered by breathing in tiny particles of allergens. The most common airborne allergens that cause rhinitis are described below.

House dust mites

House dust mites are tiny insects that feed on the dead flakes of human skin. They can be found in mattresses, carpets, soft furniture, pillows and beds.

Rhinitis is not caused by the dust mites themselves, but by a chemical found in their excrement. Dust mites are present all year round, although their numbers tend to peak during the winter.

Pollen and spores

Tiny particles of pollen produced by trees and grasses can sometimes cause allergic rhinitis. Most trees pollinate between early to mid-spring, whereas grasses pollinate at the end of spring and beginning of summer.

Rhinitis can also be caused by spores produced by mould and fungi.


Many people are allergic to animals, such as cats and dogs.

It is not animal fur that causes the allergic reaction, rather flakes of dead animal skin and their urine and saliva.

Dogs and cats are the most common culprits, although some people are affected by horses, cattle, rabbits and rodents, such as guinea pigs and hamsters.

Work-related allergens

Some people are affected by allergens found in their work environment, such as wood dust, flour dust or latex.

Who’s most at risk?

It is not fully understood why some people become oversensitive to allergens, although you are more likely to develop an allergy if there is a history of allergies in your family.

If this is the case, you are said to be ‘atopic’ or to have ‘atopy’. People who are atopic are more likely to develop allergies because they produce more IgE antibodies than other people.

Environmental factors also seem to play a part. Studies have shown certain things may increase the chance of a child developing allergies, such as growing up in a house where people smoke and being exposed to dust mites or pets at a young age.

Diagnosing allergic rhinitis

Your GP will often be able to diagnose allergic rhinitis from your symptoms and your personal and family medical history.

You will be asked if you have noticed any triggers that seem to cause a reaction, and whether it happens at a particular place or time.

Your GP may examine the inside of your nose to check for nasal polyps. Nasal polyps are fleshy swellings that grow from the lining of your nose or your sinuses (the small cavities inside your nose). They can be caused by the inflammation that occurs as a result of allergic rhinitis

Allergic rhinitis is usually confirmed when medical treatment starts. If you respond well to antihistamines, it is almost certain that your symptoms are caused by an allergy.

Allergy testing

If the exact cause of allergic rhinitis is uncertain, your GP may refer you to a hospital allergy clinic for allergy testing. The two main allergy tests are:

  • Skin prick test  where the allergen is placed on your arm and the surface of the skin is pricked with a needle to introduce the allergen to your immune system. If you are allergic to the substance, a small welt (itchy spot) will appear.
  • Blood test  to check for the immunoglobulin E (IgE) antibody in your blood. Your immune system produces this antibody in response to a suspected allergen.

Commercial allergy testing kits are not recommended as the testing is often of a lower standard than that provided by the NHS or by accredited private clinics. It is also important that the test results are interpreted by a qualified healthcare professional with detailed knowledge of your symptoms and medical history.

Further tests

In some cases, it may be necessary to have further tests in hospital to check for any complications, such as nasal polyps or sinusitis.

These tests may include:

  • a nasal endoscopy – where a thin tube with a light source and video camera at one end (endoscope) is inserted up your nose so your doctor can see the internal part of your nose
  • a nasal inspiratory flow test – where a small device placed over your mouth and nose is used to measure the air flow when you inhale through your nose
  • a computerised tomography (CT) scan – a type of scan that uses X-rays and a computer to create detailed images of the inside of the body

Treating allergic rhinitis

Treatment for allergic rhinitis largely depends on how severe the symptoms are and how much the condition is affecting your everyday activities.

In most cases, treatment aims to relieve symptoms such as sneezing and a blocked or runny nose.

If your allergic rhinitis is mild, you can often treat the symptoms yourself. You should visit your GP if your symptoms are more severe and are affecting your quality of life, or if self-help measures have not been effective


If your allergic rhinitis is mild, you can treat the symptoms yourself with over-the-counter medications, such as long-acting, non-sedating antihistamines and decongestants (see below).

If possible, you should try to take steps to reduce your exposure to the allergen that triggers the condition. See preventing allergic rhinitis for advice about this.

Cleaning your nasal passages

Regularly cleaning your nasal passages (known as nasal douching or irrigation) with a salt water solution can also help by keeping your nose free of irritants.

This can be done using either a home-made solution or a solution made with sachets of ingredients bought from a pharmacy. Small syringes or pots (which often look like small horns or teapots) are also available to help flush the solution around the inside of your nose.

To make the solution at home, mix a teaspoon of salt and a teaspoon of bicarbonate of soda into a pint of boiled water that has been left to cool to around body temperature (do not attempt to rinse your nose while the water is still hot). To rinse your nose:

  • standing over a sink, cup the palm of one hand and pour a small amount of the solution into it
  • sniff the water into one nostril at a time
  • repeat this until your nose feels comfortable (you may not need to use all of the solution)

While you do this, some solution may pass into the throat through the back of the nose. Although the solution is harmless if swallowed, try to spit out as much of it as possible.

Nasal irrigation can be carried out as often as necessary, but a fresh solution should be made each time.


Medication will not cure your allergy, but it can be used to treat the common symptoms.

If your symptoms are caused by seasonal allergens, such as pollen, you should be able to stop taking your medication after the risk of exposure has passed.

Visit your GP if your symptoms do not respond to medication after two weeks.


Antihistamines relieve symptoms of allergic rhinitis by blocking the action of a chemical called histamine, which the body releases when it thinks it is under attack from an allergen.

You can buy antihistamine tablets over the counter from your pharmacist without a prescription, but antihistamine nasal sprays are only available with a prescription.

Antihistamines can sometimes cause drowsiness. If you are taking them for the first time, see how you react to them before driving or operating heavy machinery. In particular, antihistamines can cause drowsiness if you drink alcohol while taking them.


If you have frequent or persistent symptoms, and you have a nasal blockage or nasal polyps, your GP may recommend a nasal spray or drops containing corticosteroids.

Corticosteroids help reduce inflammation and swelling. They take longer to work than antihistamines, but their effects last longer. Side effects from inhaled corticosteroids are rare, but can include nasal dryness, irritation and nosebleeds.

If you have a particularly severe bout of symptoms and need rapid relief, your GP may prescribe a short course of corticosteroid tablets lasting five to 10 days.

Nasal decongestants

Nasal decongestants help relieve a blocked nose and are usually available over the counter. They can be taken as tablets, capsules, nasal sprays or liquids.

However, nasal decongestants should not be used for more than five to seven days at a time because using them for longer than this can make your congestion worse.

You should not use nasal decongestants if you are taking a type of antidepressant known as a monoamine oxidase inhibitor (MAOI).

Add-on treatments

If your allergic rhinitis does not respond to treatment, your GP may choose to add to your original treatment. They may suggest:

  • increasing the dose of your corticosteroid nasal spray
  • using a short-term course of a decongestant nasal spray to take with your other medication
  • combining antihistamine tablets with corticosteroid nasal sprays and possibly decongestants
  • using a nasal spray that contains a medicine called ipratropium, which will help reduce excessive nasal discharge
  • using a leukotriene receptor antagonist medication (medication that blocks the effects of chemicals called leukotrienes, which are released during an allergic reaction)

If you do not respond to the add-on treatments, you may be referred to a specialist for further assessment and treatment.


Immunotherapy, also known as hyposensitisation or desensitisation, is another type of treatment used for some allergies. It is only suitable for people with certain types of allergies, such as hay fever, and is usually only considered if your symptoms are severe.

Immunotherapy involves gradually introducing more and more of the allergen into your body to make your immune system less sensitive to it.

The allergen is often injected under the skin of your upper arm, which are given at weekly intervals with a slightly increased dose each time. Immunotherapy can also be carried out using tablets that contain an allergen, such as grass pollen, which are placed under your tongue.

When you reach a dose that is effective in reducing your allergic reaction (the maintenance dose), you will need to continue with the injections or tablets for up to three years.

Immunotherapy must only be carried out under the close supervision of a specially trained doctor because there is a risk it may cause a serious allergic reaction.

Complications of allergic rhinitis

If you have allergic rhinitis, there is a risk you could develop further problems.

A blocked or runny nose can result in difficulty sleeping, drowsiness during the daytime, irritability and problems concentrating. Allergic rhinitis can also make symptoms of asthma worse.

The inflammation associated with allergic rhinitis can also sometimes lead to further conditions, such as nasal polyps, sinusitis and middle ear infections. These are described below.

Nasal polyps

Nasal polyps are fleshy swellings that grow from the lining of your nose or sinuses (the small cavities above and behind your nose), which are caused by inflammation of the membranes of the nose and sometimes develop as a result of rhinitis.

Nasal polyps are shaped like teardrops when they are growing and they look like a grape on a stem when fully grown. They vary in size and can be a yellow, grey or pink. They can grow on their own or in clusters and usually affect both nostrils.

If nasal polyps grow large enough, or in clusters, they can interfere with your breathing, reduce your sense of smell and block your sinuses, leading to sinusitis (see below).

Small nasal polyps can be shrunk using steroid nasal sprays so they do not cause an obstruction in your nose. Large polyps may need to be surgically removed.

Read more about treating nasal polyps.


Sinusitis is a common complication of rhinitis. It is where sinuses become inflamed or infected.

The sinuses naturally produce mucus, which usually drains into your nose through small channels. However, if these drainage channels are inflamed or blocked (for example, because of rhinitis or nasal polyps), the mucus cannot drain away and it may become infected.

Common symptoms include:

  • severe facial pain around your cheeks, eyes or forehead
  • toothache
  • a blocked or runny nose – your nose may produce a green or yellow mucus
  • a high temperature (fever)

Symptoms of sinusitis can be relieved using over-the-counter painkillers, such as paracetamol, ibuprofen or aspirin. These will help reduce the pain and fever.

However, these medications are not suitable for everyone so check the leaflet that comes with them before you take them. For example, children under 16 years of age should not take aspirin, and ibuprofen is not recommended for people with asthma or a history of certain stomach conditions, such as stomach ulcers. Speak to your GP or pharmacist if you are unsure.

Antibiotics may also be recommended if your sinuses become infected with bacteria. In cases of long-term (chronic) sinusitis, surgery may be needed to improve the drainage of your sinuses.

Read more about treating sinusitis.

Middle ear infections

Middle ear infections (otitis media) can also develop as a complication of nasal problems, including allergic rhinitis.

These infections may occur because rhinitis can cause a problem with the Eustachian tube at the back of the nose. If this tube (which connects the back of the nose and the middle ear) does not function properly, then fluid may accumulate in the middle ear (behind the ear drum) and this fluid can then become infected.

There is also the possibility of infection at the back of the nose spreading to the ear through the Eustachian tube.

Symptoms of a middle ear infection can include:

Most ear infections clear up within a couple of days, although paracetamol or ibuprofen can be used to relieve pain and a high temperature. Antibiotics may also be used if the symptoms persist or are particularly severe.

Read more about treating middle ear infections.

Preventing allergic rhinitis

The best way to prevent allergic rhinitis is to avoid the allergen that causes it.

However, this is not always easy. Allergens, such as dust mites, can be hard to spot and can breed in even the cleanest house. It can also sometimes be difficult to avoid coming into contact with pets, particularly if they belong to friends and family.

Below is some advice to help you avoid the most common allergens.

House dust mites

Dust mites are one of the biggest causes of allergies. They are microscopic insects that breed in household dust. Below are a number of ways that you can limit the amount of mites in your house:

  • consider buying air-permeable occlusive mattress and bedding covers (this type of bedding acts as a barrier to dust mites and their droppings)
  • choose wood or hard vinyl floor coverings instead of carpet
  • fit roller blinds that can be easily wiped clean
  • clean cushions, soft toys, curtains and upholstered furniture regularly – either by washing or vacuuming them
  • use synthetic pillows and acrylic duvets instead of woollen blankets or feather bedding
  • use a vacuum cleaner fitted with a high efficiency particulate air (HEPA) filter because it can remove more dust than ordinary vacuum cleaners
  • use a damp, clean cloth to wipe surfaces because dry dusting can spread the allergens further

Concentrate your efforts on controlling dust mites in the areas of your home where you spend most time, such as the bedroom and living room.


It is not pet fur that causes an allergic reaction, but exposure to flakes of their dead skin, saliva and dried urine. If you cannot permanently remove a pet from the house, you may find the following tips useful:

  • keep pets outside as much as possible or limit them to one room, preferably one without carpet
  • do not allow pets in bedrooms
  • wash pets at least once a fortnight
  • groom dogs regularly outside
  • regularly wash all bedding and soft furnishings your pet has been on

If you are visiting a friend or relative with a pet, ask them not to dust or vacuum on the day you are visiting because it will disturb allergens into the air. Taking an antihistamine medicine one hour before entering a pet-inhabited house can help to reduce your symptoms.


Different plants and trees pollinate at different times of the year, so when you get allergic rhinitis will depend on what sort of pollen(s) you are allergic to.

Most people are affected during spring and summer months because this is when most trees and plants pollinate. To avoid exposure to pollen, you may find the following tips useful:

  • check weather reports for the pollen count and stay indoors when it is high
  • avoid line-drying clothes and bedding when the pollen count is high
  • wear wraparound sunglasses to protect your eyes from pollen
  • keep doors and windows shut during mid-morning and early evening, when there is most pollen in the air
  • shower, wash your hair and change your clothes after being outside
  • avoid grassy areas, such as parks and fields, when possible 
  • if you have a lawn, consider asking someone else to cut the grass for you 

Mould spores

Moulds can grow on any decaying matter, both in and outside the house. The moulds themselves aren’t allergens but the spores they release are. Spores are released when there is a sudden rise in temperature in a moist environment, such as when central heating is turned on in a damp house, or wet clothes are dried next to a fireplace.

Here are some ways that you can prevent mould spores:

  • keep your home dry and well ventilated
  • when showering or cooking, open windows but keep internal doors closed to prevent damp air from spreading through the house and use extractor fans
  • do not dry clothes indoors, store clothes in damp cupboards or pack clothes too tightly in wardrobes
  • deal with any damp and condensation in your home