Key Messages:

The American Academy of Allergy, Asthma and Immunology recommends routine penicillin skin testing in patients with self-reported penicillin allergies. This recommendation stems from reports that patients with penicillin allergy have an increased risk of adverse patient outcomes due to serious drug-resistant infections. Longer hospital stays also increase healthcare resources.

• Penicillin allergic patients can be evaluated at VMC's Allergy & Immunology Clinic (referral reason: penicillin allergy).
• Patients who have experienced allergic reactions to penicillin antibiotics (e.g. blistering skin rash, oral lesions, skin sloughing) should continue to avoid the culprit antibiotic. Penicillin skin testing should not be performed in these individuals due to risk of triggering another serious reaction.

Background:

In 2016, the American Academy of Allergy, Asthma and Immunology published a position statement recommending that “penicillin allergy testing should be performed routinely in patients with self-reported penicillin allergy.” Only about 1-8% of these individuals have a positive penicillin skin test when tested, despite an estimated 10-20% reporting a penicillin allergy. The reaction may have been due to adverse side effects, rash due to other causes, like the underlying infection itself, and possibly outgrowing the IgE-mediated allergy over time.

Unverified penicillin allergies lead to longer hospital stays and serious drug-resistant infections. These adverse patient outcomes and increased healthcare resources are avoidable and have been recognized by the Choosing Wisely program of the American Board of Internal Medicine Foundation. In 2014, it was recommended to appropriately evaluate patients with a history of penicillin allergy to avoid overuse of non-beta lactam antibiotics.

Penicillin skin testing is standardized with a negative predictive value that is close to 100% and a positive predictive value that is between 40-100%. The skin test evaluates for IgE-mediated reactions only. There are certain individuals who should never be exposed to the culprit penicillin antibiotic again. The test can potentially evoke a reaction in those who have experienced severe cutaneous adverse reactions, like Stevens Johnson Syndrome, or serum sickness like reactions.

Considerations:

• A negative penicillin skin test is always confirmed with an oral challenge. The best time to perform a challenge is when an individual is in good health, and before infection and the urgent need for antibiotics. Challenges can be performed in the outpatient setting by clinicians who can safely treat potential anaphylactic reactions.
• The increased use of routine penicillin skin testing in those with self-reported penicillin allergies is expected to reduce costs and improve safety outcomes.
• The Allergy and Immunology Clinic can evaluate individuals with a history of IgE-mediated or unknown reactions to penicillin antibiotics.
• Penicillin skin testing is contraindicated in those who have experienced blistering skin rashes, oral lesions, skin sloughing, fevers and joint pains after receiving these antibiotics.
• The penicillin skin tests involves intradermal injections. Unless there is an urgent need for a penicillin antibiotic, it would be preferred to delay the skin test until a pediatric patient is older than age 4.

If there are any questions, please contact Dr. Chong at Melanie_Chong@valleymed.org.

References:

Penicillin Allergy in Antibiotic Resistance Workgroup. Penicillin allergy testing should be performed routinely in patients with self-reported penicillin allergy. J Allergy Clin Immunol Pract. 2017 Mar – Apr;5(2):333-334.

Joint Task Force on Practice Parameters. Drug allergy: an updated practice parameter. Ann Allergy Asthma Immunol. 2010 Oct;105(4):259-273.