Diagnosis - Allergic Rhinitis

Your GP can often diagnose allergic rhinitis from your symptoms and medical history.

They'll ask if the reaction happens at a particular place or time or if anything triggers it.

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 sinuses (the small cavities inside your nose). The swelling that happens as a result of allergic rhinitis can cause nasal polyps.

Your GP can confirm a diagnosis of allergic rhinitis when treatment starts. If your symptoms improve after taking antihistamines, it's likely that it's caused by an allergy.

Allergy testing

If the exact cause of allergic rhinitis is uncertain, your GP may refer you for allergy testing.

Commercial allergy testing kits are not recommended. The tests are often of a lower standard than that provided by qualified healthcare professionals.

Test results need to be reviewed by a professional with detailed knowledge of your symptoms and medical history.

There are 2 main allergy tests:

Skin prick tests

The tester places the allergen on your arm and pricks the surface of your skin with a needle. This introduces the allergen to your immune system.

If you're allergic to the substance, a welt (small itchy spot) appears.

Blood tests

Blood tests check for the immunoglobulin E (IgE) antibody in your blood. Your immune system produces this antibody in response to an allergen.

Other tests

You may need other hospital tests to check for complications, such as nasal polyps or sinusitis.

You may need a:

  • nasal endoscopy – your doctor looks inside your nose using an endoscope (a thin tube with a light and video camera at the end)
  • nasal inspiratory flow test – your doctor places a small device over your mouth and nose. They measure the airflow when you breathe in through your nose
  • CT scan – a scan that uses x-rays and a computer to create detailed images of the inside of the body


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

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