Prick, patch or blood test? A simple guide to allergy testing

This article provides information on allergy testing and serves as a simple guide for physicians who are considering using allergy testing as a step in patient management. Basic principles of allergy testing, indications for testing, and how and when to choose a suitable allergy test are discussed. Allergy testing in general refers to evaluation of either type I or type IV hypersensitivity reactions. The type I (immediate) reaction is evaluated using the skin prick test (in vivo) or serum IgE (in vitro) test methods, while the type IV (delayed) reaction is determined via the skin patch test method. The allergens responsible for a specific reaction can be identified from allergy testing, and this information is useful in administering avoidance measures. Appropriate treatment of allergic reactions along with allergen avoidance ensure a successful treatment outcome and prevent future reactions.