Your GP should be able to diagnose hay fever from a description of your symptoms. In some cases, you may be referred for allergy testing.
A diagnosis for hay fever would usually only be required:
- if your symptoms were particularly severe
- the pattern of your symptoms was unusual – for example, if you have symptoms during the winter or while indoors
- if you had experienced complications of hay fever
If possible, keep a diary of the times of day or year you experience your symptoms, as this can help with the diagnosis.
Your GP may refer you to an immunologist for an allergy test if you have hay fever symptoms all year round (called persistent allergic rhinitis), or symptoms that aren't responding to treatment. Other substances could be causing your allergy, such as house dust mites, animals or certain foods.
The two main allergy tests are a skin prick test and a blood test.
Skin prick test
During a skin prick test, an immunologist will place the pollen allergen on your arm and prick the surface of your skin with a needle. This will introduce the allergen to your skin's immune system (mast cells) and, if you're allergic to it, you should have a reaction on the skin.
If your skin starts to go red around where it was pricked, swells up or becomes itchy, this could be an allergic reaction and would confirm that you have hay fever.
A skin prick test may not be suitable if:
- you're on certain medications, such as antihistamines, which will stop you having an allergic reaction
- you have significant eczema, as your skin may already be red or itchy, so an allergic reaction won't be noticeable
In this case, a blood test may be necessary to confirm your diagnosis (see below).
The use of commercial home allergy testing kits isn't recommended. The testing is often of a lower standard than that provided by the NHS or accredited private clinics. It's also important that the test results are interpreted by a qualified professional who has detailed knowledge of your symptoms and medical history.
A sample of blood will be taken from a vein in your arm and tested for the presence of the Immunoglobulin E (IgE) antibody.
If you have hay fever, your body produces this antibody when it comes into contact with pollen. If your blood tests positive for IgE, this may confirm that you have hay fever.