Allergy testing can help confirm or rule out allergies and consequently reduce adverse reactions and limit unnecessary avoidance and medications. Correct allergy diagnosis, counseling and avoidance advice based on valid allergy test results is of utmost importance and can help reduce the incidence of symptoms, need for medications and improve quality of life. A healthcare provider can use the test results to identify the specific allergic triggers that may be contributing to the symptoms. Using this information, along with a physical examination and case history, the doctor can diagnose the cause of the symptoms and tailor treatments that will help the patient feel better. A negative result can help the doctor rule out allergies in order to consider other possibilities. Ruling out allergies is as important as confirming them to limit unnecessary avoidance, worry and negative social impact.
NIH guidelines for the diagnosis and management of food allergy and the diagnosis and management of asthma recommend either allergy blood testing or skin prick testing to reliably determine allergic sensitization.
For an allergy blood test, a sample of the patient’s blood is sent to a laboratory for analysis. The doctor looks at the test results to help determine if the patient has allergies. For babies and young children, a single needle stick for allergy blood testing is often more gentle than several skin tests.
For a skin prick test, a patient is pricked with a series of needles that contain extracts of allergic triggers. The doctor looks for strong reactions like welts or red bumps to determine if the patient has allergies. This method, although unpleasant for young children and people who dislike needle pricks, is beneficial because the person may discover an acute allergy with a trained health-care staff ready to stop life-threatening allergic reactions, which can save the patient from an unexpected anaphylactic reaction. It may also allow the person to gain the tools needed if anaphylaxis ever occurs again, such as, a mobile epinephrine pen that acts as a vasoconstrictor, allowing the person to regain a patent (open) airway, and breath, until emergency services arrive.