Skin Scrape Test: An Inexpensive and Painless Skin Test For Recognition Of Immediate Hypersensitivity In Children And Adults

Background: Skin testing is a mainstay in allergology, and its importance is increasing in several fields. The ability to choose the most suitable technique according to the clinical setting is an advantage for the medical team. Objectives: To describe in detail an alternative technique of the coetaneous allergy test (skin scrape test) conceived as a variation of the former skin scratch test; to evaluate its value as a tool for diagnosis of immune sensitization; and to com- pare its accuracy with the skin prick test. Methods: The skin scrape test and skin prick test were performed side by side with the same allergen extracts in 162 hu- man subjects classified in two groups according to the known presence or absence of serum specific-IgE to these aller- gens. Results: The sensitivity of the skin scrape test to detect immediate reactions was 85.0%. The sensitivity of the skin prick test was 86.5%. The sensitivity of both techniques analyzed together as a unique procedure was 94.2%. The specificity of the skin scrape test was 90.1%.The specificity of the skin prick test was 72.9%.The specificity of both tests analyzed to- gether as a unique procedure was 70.5%. Conclusions: The skin scrape test is an alternative and complementary technique for allergic skin testing, and it is able to detect IgE-specific immune sensitization without the disadvantages of the skin scratch test. The skin scrape test has simi- lar outcomes to the skin prick test.