The test is done by injecting a small amount of penicillin underneath the skin. If the next day, a red bump forms and the surrounding area looks swollen, then the person is most likely allergic. If not, then the person is not allergic to penicillin. A blood test is also available to help determine any penicillin allergies. https://www.beleefstaverden.nl/how-to-find-reliable-writing-services/