Antimicrobial Stewardship

Penicillin allergy testing can be a safe and effective
strategy to reduce the use of broad spectrum
antibiotics and can help modify antibiotic selection.

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Penicillin Allergy

Penicillin allergy is the most commonly reported drug allergy in the United States however only 9 out 10 patients who report as allergic are truly allergic when skin tested, Because of this, patients often receive antibiotics that are not optimal for their condition which can result in treatment delays and increased costs.

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Implementing Penicillin
Skin Testing in Your Hospital

Penicillin skin testing can benefit your hospital in many clinical areas including pre-op testing, Infectious Disease, ICU, ER as well as out-patient clinics.

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Indications and Usage


PREPEN (benzylpenicilloyl polylysine injection USP) is the only FDA approved skin test for the diagnosis of penicillin allergy.

PRE-PEN is indicated for the assessment of sensitization to penicillin (benzylpenicillin or penicillin G) in patients suspected to have clinical penicillin hypersensitivity. A negative skin test to PRE-PEN is associated with an incidence of immediate allergic reactions of less than 5% after the administration of therapeutic penicillin, whereas the incidence may be more than 50% in a history-positive patient with a positive skin test to PRE-PEN. These allergic reactions are predominantly dermatologic. Whether a negative skin test to PRE-PEN predicts a lower risk of anaphylaxis is not established. Similarly, when deciding the risk of proposed penicillin treatment, there are not enough data at present to permit relative weighing in individual cases of a history of clinical penicillin hypersensitivity as compared to positive skin tests to PRE-PEN and/or minor penicillin determinants.

Full Prescribing Information

PREP-PEN® (benzylpenicilloyl polylysine injection USP)

Important Safety Information

The risk of sensitization to repeated skin testing with PRE-PEN is not established. Rarely, a systemic allergic reaction including anaphylaxis may follow a skin test with PRE-PEN. To decrease the risk of a systemic allergic reaction, puncture skin testing should be performed first. Intradermal skin testing should be performed only if the puncture test is entirely negative.

PRE-PEN is contraindicated in those patients who have exhibited either a systemic or marked local reaction to its previous administration. Patients known to be extremely hypersensitive to penicillin should not be skin tested. Please see the package insert for full prescribing information.

No single skin test or combination of tests can completely assure that a reaction to penicillin therapy will not occur.

1Salkind, Alan, R. et all. Is This Patient Allergic to Penicillin? JAMA, May 16, 2001 - Vol. 285, No. 19
2Park, Miguel. Li, James T. Diagnosis and Management of Penicillin Allergy. Mayo Clin Proc. March 2005; 80(3):405-410
3Raja, Ali S. et all. The Use of Penicillin Skin Testing to Assess The Prevalence of Penicillin Allergy in am Emergency Department. Annals of Emergency Medicine. Volume 54, No. 1: July 2009