Understanding Allergies

Child Holding an Insect

What is an allergy?

Our immune system is designed to protect the body against foreign substances. Sometimes, this system overreacts by detecting harmless substances as threatening.

A person without allergies would have no reaction to this substance. An allergic person reacts to the usually harmless substance and their body produces antibodies to attack it. This sets off a complex chain reaction which causes the release of chemicals in your body including histamines. It is this chemical which causes the typical symptoms of an allergy, such as sneezing, itchy eyes or a runny nose.

For example, in hayfever, the immune system overreacts to pollen, and the release of histamine causes symptoms like sneezing, runny nose, itchy nose and watery eyes.

Be prepared

Whatever your allergy, be prepared with Piri...

Arm yourself with advice, support and services, whether it's knowing where your nearest outlet is to purchase products or having a look at the Understanding Allergies section on our website to know what your triggers are.

Take effective products at the first sign of symptoms and consult your GP if your symptoms do not improve after the duration stated within the product information leaflet.

...it's all about being prepared and ready so that you can act before you react.


See information on the types of allergies that can affect you


See which symptoms we can help alleviate


What's triggering your symptoms? Find out here


Find the right treatment for your symptoms

Understanding Allergies: What is an Allergic Reaction?

Child holding an insect


How does an allergic reaction happen?

Our immune system is designed to protect our body against foreign substances – like viruses and other germs – to help keep up safe and healthy. But sometimes, our immune system can overreact and mistake a harmless substance as threatening. This is exactly what occurs during an allergic reaction.

Some of the most common harmless, everyday substances that can trigger an allergic reaction include:i

  • Grass and tree pollen (this allergic reaction is known as hay fever)
  • Dust mites
  • Mould
  • Food (such as eggs, nuts or shellfish)
  • Dander (tiny flakes of skin or hair) from household pets and other animals
  • Certain medications
  • Latex
  • Some household chemicals

Of course, anyone who suffers with an allergy knows how much of a nuisance they can be during your daily life. Thankfully, however, most allergic reactions are mild and can be easily managed, while severe allergic reactions are much rarer.i

Learn more about different types of allergies.

What are the symptoms of an allergic reaction?

If you have an allergy, coming into contact with the irritant (or ‘allergen’) that you are allergic to triggers a protective response in your body, and it begins to produce antibodies to defend itself. As part of this defense, your body will release certain chemicals, including histamines.

It’s these chemicals that are responsible for your allergy symptoms, which will typically occur within minutes of your exposure to an allergen. They may include:i

  • sneezing, a runny or blocked nose,
  • red, itchy, watery eyes
  • wheezing and coughing
  • a red, itchy skin rash
  • worsening of asthma or eczema symptoms

Since some of these symptoms are similar to those you might experience with the common cold, a flu or sinusitis (sinus infection),ii, iii it can sometimes be difficult to tell whether your symptoms are due to an allergic reaction or illness.

If you’re unsure as to what’s causing your symptoms, consult our simple Symptomcheck comparison table to help you determine whether it’s an allergy or a virus that’s getting you down.

When in doubt, however, you should always consult your GP or pharmacist.

Who gets allergies?

Allergies are extremely common. Roughly 1 in 5 people in the UK are thought to be affected by an allergy at some point in their lives.i In fact, the rate of people developing allergies in the UK and other parts of the world is actually increasing with each year – however the reason for this is not yet fully understood.i, iv

Anyone can suffer from an allergic reaction, however allergies tend to be more common in children. An allergy may go away as a child grows up or stick around well into adulthood.i

You’re also more at risk of developing an allergy if allergies run in your family, or if you have asthma or eczema.i

How is an allergy diagnosed?

There are a few different methods of allergy testing available. If you think you may have an allergy, speak to your GP. They can recommend the best testing method for you based on your symptoms and personal history.

Common forms of allergy tests include:iv, v

  • Skin prick testing
  • Blood tests
  • Patch testing (for suspected eczema)
  • Elimination diets (for suspected food allergies)

Most of these tests involve exposing you to a small amount of a suspected allergen to see if it triggers an allergic reaction. If an allergy is confirmed, your GP can determine an appropriate treatment method to suit you.


How do you treat an allergic reaction?

While many allergic reactions are mild, there’s no denying that allergy symptoms can still be a real headache. They can make you feel frustrated, tired, groggy or just not yourself. Many common allergy symptoms (like a constantly runny nose or itchy, red or watery eyes)i can even get in the way of everyday life, making basic tasks like concentrating on your work more difficult. Thankfully, there are plenty of allergy treatment options available that can help you manage allergy symptoms.

Over-the-counter allergy relief medication comes in many different forms to suit any allergy sufferer – from corticosteroid nasal sprays, to anti-allergy tablets, syrups and nasal washes.

You can find all of the above in the Piri Allergy product range, including Pirinase Allergy nasal spray and Piriteze syrup and tablets – designed to provide you with fast, effective relief from symptoms when allergies strike.

Learn more about different allergy treatments and discover the complete range of allergy relief products from Piri Allergy – including products to help treat allergies in children.

Sources: Clicking any of the links below takes you to an external website that is independently operated and not managed by Haleon. Haleon assumes no responsibility for the content on the website. If you do not wish to leave this website, do not click on the links below.

  1. Allergies. NHS. https://www.nhs.uk/conditions/allergies/. Accessed 27/01/21.
  2. Cold, flu or allergy? National Institutes of Health. https://newsinhealth.nih.gov/2014/10/cold-flu-or-allergy. Accessed 27/01/21.
  3. Sinus infection. NHS. https://www.nhs.uk/conditions/sinusitis-sinus-infection/. Accessed 27/01/21.
  4. Allergy. British Society for Immunology. https://www.immunology.org/policy-and-public-affairs/briefings-and-position-statements/allergy. Accessed 27/01/21.
  5. Allergies (diagnosis). NHS. https://www.nhs.uk/conditions/allergies/diagnosis/. Accessed 27/01/21.