Allergy skin testing

Abstract

Skin prick test (SPT) is used for immunoglobulin E (IgE)-mediated allergic disorders. It is an “in vivo” test for detecting allergen-specific IgE antibodies bound to mast cells. The cutaneous reaction in the form of wheal-and-flare response that develops following application of allergen extract serves as a surrogate marker for confirming “sensitization” to a specific allergen and it does not necessarily indicate allergy. Allergy is a clinical term, which is to be used when the patient is symptomatic along with positive SPT. SPT is considered a gold-standard investigation for IgE-mediated allergies since it is minimally invasive, inexpensive, easy to perform, relatively painless, provides quick results, and has good clinical correlation. An allergy test should always be individualized based on history, clinical features, geographical region where the patient resides, diagnostic efficacy of the test, and cost–benefit analysis. And finally, it is of utmost importance to consider negative and positive controls while interpreting allergy skin test along with clinical symptoms.