Is Skin Test Required for Diagnosis of Drug Allergy?

While skin tests are effective in diagnosing allergy to some drugs, they are very sensitive to some drugs. Since allergic reactions may occur during drug allergy testing, it should be done in a center where all kinds of precautions are taken and anaphylaxis treatment can be done. In this article, we have written skin tests for the diagnosis of drug allergy.

Skin tests such as skin prick testing (SPT) and intradermal testing (allergen injected test) are useful for diagnosing IgE-mediated (type I) reactions.

Skin tests are standardized for penicillin, it is done with special solutions. Local anesthetics are useful (but rarely positive) for muscle relaxants and are very sensitive to high molecular weight protein substances such as insulin or monoclonal antibodies. Positive skin tests against these drugs confirm the presence of antigen-specific IgE and support the diagnosis of a type I hypersensitivity reaction.

First of all, since allergic reactions may occur during the diagnosis of drug allergy, especially during intradermal tests, it should be done by allergy specialists in a center where anaphylaxis treatment can be done and all kinds of precautions are taken. Incorrect performance and interpretation of tests may lead to incorrect identification of the patient as allergic. Skin tests may sensitize the patient to the drug. Therefore, it should not be done unless necessary. Therefore, if a drug-induced allergic disorder is suspected, it is recommended to consult an allergist experienced in the diagnosis and treatment of drug allergy.

Specific IgE tests in serum are available for a limited number of drugs. However, these tests are costly and generally less sensitive than skin tests. Also, blood tests are not enough for most of them.