How to Diagnose a Medication Allergy

You must report any abnormal drug reactions to your doctor. The doctor will determine the underlying cause of your symptoms and to find out whether your reaction is allergic or nonallergic.

According to the World Allergy Organization (WAO), if you react to a drug with visible symptoms, there is about one in 10 chance that it is an allergic reaction. Knowing whether your reaction is allergic or nonallergic is very important because allergic reactions can develop into life-threatening anaphylactic shock in the future.

Nonallergic drug reactions

Diagnosing Medication Allergy

Nonallergic reactions may be a side effect of the drug. Side effects are secondary reactions to medications that may occur in healthy people. This reaction can be detrimental or beneficial. Most side effects can be known before the drug is prescribed. (Your doctor must tell you about the side effects that can occur before prescribing medication).

Sometimes, low doses can reduce or eliminate negative side effects.

Nonallergic reactions can be special (ordinary and unexpected). This can occur after your first exposure to the drug. Idiosyncratic reactions are not a common side effect and are often due to genetic or metabolic abnormalities.

In some cases, your reaction to the drug can mimic an allergic reaction. This is called pseudoallergy or sensitivity. In some cases, this is a side effect of the drug. This can occur during the first use of the drug. For example, many people who use narcotic pain relievers such as codeine experience itching.

Test for diagnosing drug allergy

The first step in the diagnosis of drug allergy is a complete physical examination. Your doctor will find out if you have other allergies or a family history of allergies. He will also find out how long it has been since you took the drug before your reaction began and whether you have used the drug before. You will be asked to explain your symptoms in detail.

If possible, check with your doctor when you experience a reaction to a drug. This will help the doctor make a diagnosis. If your doctor suspects a drug allergy, they can do several tests to confirm the diagnosis.

Skin test

For some medications, a skin allergy test can determine whether you are allergic to a substance. Depending on the type of drug, the doctor may do a puncture skin test or an intradermal test.

During a skin-prick test, the doctor injects a small amount of the drug into the skin - usually the back or forearm. If you are allergic, you will experience skin redness, bumps, or other skin inflammation.

Intradermal tests can test allergic reactions to penicillin and several other antibiotics. During this test, the doctor injects a small amount of allergen just under the skin and monitors the injection site for a reaction.

Blood test

Blood tests can determine whether you are allergic to certain drugs. Although blood tests are not as accurate as other test methods, your doctor may choose to do blood tests if there is a concern that you will have an anaphylactic reaction to the drug. Because blood is tested outside your body there is no risk of allergic reactions.

You may experience pain in the place where the blood is drawn. Blood tests can only detect allergies from certain medications, such as some antibiotics, muscle relaxants, and insulin.

Provocation test

In provocation tests, increased doses of the drug are carried out at planned intervals. You can use drugs orally or under the skin. Reactions indicate the possibility of allergies or sensitivity to the drug. If the reaction is mild or if there is no reaction, the drug may be a safe treatment for the patient. Risks of provocation tests include severe reactions, even potentially anaphylaxis. This test is only used in special cases and is usually done only in special allergy centers.