1. What are the signs and symptoms of penicillin allergy?
People who are allergic may have any of the following symptoms within an hour of taking the drug:
- Hives (red welts)
- Swelling, commonly of the lips, eyes, tongue, hands, or feet.
- Shortness of breath or wheezing
- In severe reactions, fainting can occur
2. Who should be tested for penicillin allergy?
Anyone who has a history of an allergic reaction to penicillin is a candidate for testing. The Centers for Disease Control and Prevention (CDC) recommends that anyone with a history of penicillin allergy be evaluated and, if necessary, tested before being prescribed broad-spectrum antibiotics.
3. Why should I be tested for penicillin now if I do not need to take the antibiotic immediately?
Penicillin is a commonly used antibiotic with a variety of applications. For certain infections, it is the most effective antibiotic available. Demonstrating the absence of allergy now could be very helpful to you in the future when the need might suddenly arise – such as during an emergency or surgery.
95% of people labeled allergic turn out to have negative testing and can take penicillin again without problems.
Simply avoiding penicillin may sound simple, but there are risks:
• You may be prescribed other antibiotics which don’t work as well for the infection you have.
• These other antibiotics tend to cause more adverse reactions, such as kidney injury, diarrhea, or further infections with drug-resistant bacteria.
4. How is penicillin allergy testing done?
Allergy skin tests are performed most commonly on either the forearm or back. If the skin test is negative, an oral challenge to penicillin is performed in the office on the same day. During a challenge, the patient takes penicillin in the physician’s office while under observation.
5. How should I prepare for penicillin skin testing?
You should discontinue antihistamines 5 days prior to testing as they may affect the test results.
6. Is penicillin allergy testing safe?
Yes. Skin testing to penicillin is a safe procedure. The test, if positive, will cause itching, redness, and swelling only on your skin where the test is performed. These symptoms will resolve on their own.
7. Is penicillin testing accurate?
Yes. There are no known cases of patients who had negative testing but still had a severe immediate reaction when taking penicillin.