A formal medical diagnosis is especially important for children as one allergy can escalate into multiple allergies, and because allergic rhinitis can lead to asthma. An early diagnosis can enable preventative treatment to begin so that the impact of any allergy can be minimised.
A 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 a medical history and symptoms, and a simple confirmatory diagnostic 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 – to the skin using a needle. Where an allergy exists, 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.