24/06/2026
Allergies
An allergy is a reaction the body has to a substance.
Allergies are very common. They affect more than 1 in 4 people in Europe at some point in their lives.
They're particularly common in children. Some allergies go away as a child gets older. Many are lifelong.
Adults can develop allergies to things they were not allergic to before.
Having an allergy can be a nuisance and affect your everyday activities. Most allergic reactions are mild and can be kept under control.
Severe reactions can occur, but these are rare.
Common allergies
Substances that cause allergic reactions are called allergens.
The more common allergens include:
grass and tree pollen – an allergy to these is known as hay fever (allergic rhinitis)
dust mites
flakes of skin or hair from animals
food – particularly nuts, fruit, shellfish, eggs and cows' milk
insect bites and stings
medicines – including ibuprofen, aspirin and certain antibiotics
latex – used to make some gloves and condoms
mould – these can release small particles into the air that you can breathe in
household chemicals – including those in detergents and hair dyes
Most of these allergens are harmless to people who are not allergic to them.
Symptoms of an allergic reaction
Allergic reactions usually happen within a few minutes of exposure to an allergen.
They can cause:
sneezing
a runny or blocked nose
red, itchy, watery eyes
wheezing and coughing
a red, itchy rash
worsening of asthma or eczema symptoms
Managing an allergy
The most effective way of managing an allergy is to avoid the allergen that causes the reaction.
For example, if you have a food allergy, check a food's ingredients list for the allergen before eating it.
Medicines that help control symptoms of allergic reactions include:
Antihistamines – you can take these when you notice the symptoms of a reaction, or before being exposed to an allergen, to stop a reaction occurring
Decongestants – tablets, capsules, nasal sprays or liquids used as a short-term treatment for a blocked nose
lotions and creams, such as moisturising creams (emollients) can reduce skin redness and itchiness
Steroid medicines – can help reduce redness and swelling caused by an allergic reaction
