If you have an allergic reaction to a prescription or over-the-counter medication, your doctor may need to perform some tests in order to confirm your allergy. These may include:
some drugs, an allergy skin test can be used to uncover whether you are
allergic. During a skin-prick test, a minute amount of the drug is injected
into the skin—usually the back or forearm. A drug reaction will be deemed an
allergic one if redness, a bump, or other noticeable skin inflammation develops.
There are also intradermal tests that demonstrate Immunoglobulin E (IgE)
allergies for only a few medications, among them penicillin and some other
antibiotics. In this method, a small amount of the allergen is injected just
under the skin and the site is monitored for a reaction. Either a skin-prick
test or an intradermal test may be used, depending on the drug in question.
Drug provocation testing
In certain serious situations in which a patient’s sensitivity is not known
regarding a powerful drug, provocation testing is performed; increasing doses
of the drug—taken orally or under the skin—are given at planned intervals. If
reaction to the drug does not indicate an allergy, the drug may be a safe
treatment for the patient. The risk involved with this kind of testing includes
a severe reaction, potentially even anaphylaxis.