Seeking medical attention is especially important for children as a single initial allergy can deteriorate into multiple allergies, and because allergic rhinitis can lead to asthma. An early diagnosis is therefore important  so preventative treatment can begin and the impact of the allergy minimised.

The diagnosis is typically made based on symptoms, a physical examination and a series of questions. In some cases, an allergy specialist can identify what is causing the allergy just from your medical history and symptoms, and supported by a confirmatory test.

Testing by skin prick test or blood test
A skin prick test ‘provokes’ an allergic reaction by introducing a tiny amount of allergen – the substance which doctors think you may be allergic to – into the skin using a lancet. If you are allergic, the skin will react and something similar to a mosquito bite will appear where the allergen was applied.

A blood test can be used on its own, or to support the results of the skin prick test. The blood is tested for immunoglobulin E (IgE) antibodies, which are substances produced by the body when there is an allergic reaction.   If high levels of IgE antibodies are found in the blood and related symptoms are also present, then this will help to confirm the diagnosis.