Beta-lactam Allergy risk assessment |
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Frequently Asked Questions
What is the risk of withholding cephalosporins for common infections in patients with labeled penicillin allergies
The use of alternative non-beta-lactam antibiotics such as clindamycin, fluoroquinolones, and vancomycin have been associated with negative consequence resulting in treatment failure, adverse events, drug reactions, antibiotic resistance, healthcare-associated infections, and a rise in healthcare costs.
Patients with a penicillin allergy history who resort to a non-beta-lactam antibiotic for common infections have a 23% increased odds of C. difficile infection, a 14% increased odds of MRSA infection, and 30% increased odds of VRE infection.
References:
Macy E, Contreras R. Health care use and serious infection prevalence associated with penicillin “allergy” in hospitalized patients: a cohort study. J Allergy Clin Immunol 2014;133:790-6.
Lee RU. Penicillin Allergy Delabeling Can Decrease Antibiotic Resistance, Reduce Costs, and Optimize Patient Outcomes. Fed Pract 2020;37(10):460-465.
Patients with a penicillin allergy history who resort to a non-beta-lactam antibiotic for common infections have a 23% increased odds of C. difficile infection, a 14% increased odds of MRSA infection, and 30% increased odds of VRE infection.
References:
Macy E, Contreras R. Health care use and serious infection prevalence associated with penicillin “allergy” in hospitalized patients: a cohort study. J Allergy Clin Immunol 2014;133:790-6.
Lee RU. Penicillin Allergy Delabeling Can Decrease Antibiotic Resistance, Reduce Costs, and Optimize Patient Outcomes. Fed Pract 2020;37(10):460-465.
Do I need to routinely test a patient with an unconfirmed* penicillin allergy before treating with a cephalosporin?
No, routine penicillin allergy testing (i.e. penicillin skin test and/or drug challenges) when assessing for tolerance to a cephalosporin in the setting of an unconfirmed* penicillin allergy does not improve overall patient safety or clinical outcomes because of the high number needed to treat, time, expense, and the low likelihood of such testing occurring, and will potentially result in ever greater use of less effective none beta-lactam antibiotics.
*unconfirmed penicillin allergy: a reported adverse reaction or intolerance after receiving a penicillin without verification of an IgE-mediated reaction (i.e. penicillin skin test and/or drug challenge)
References:
*unconfirmed penicillin allergy: a reported adverse reaction or intolerance after receiving a penicillin without verification of an IgE-mediated reaction (i.e. penicillin skin test and/or drug challenge)
References:
- Macy E, Contreras R. Adverse reactions associated with oral and parenteral use of cephalosporins: a retrospective population-based analysis. J Allergy Clin Immunol 2015;135:745-752.e745.
- Macy E, Blumenthal KG. Are Cephalosporins Safe for Use in Penicillin Allergy without Prior Allergy Evaluation? Ann Allergy Asthma Immunol 2017;6:82-89.
- Khan DA, Banerji A, Blumenthal KG, et al. Drug allergy: a 2022 practice parameter update. J Allergy Clin Immunol 2022;150:1333–93.
Is the cross reactivity between penicillins and cephalosporins 8-10%?
No, cross reactivity between penicillin and cephalosporins occurs in about 2% of cases.
Prior rates of 8-10% were an over estimation of the degree of cross-reactivity between beta-lactams due to 1) cephalosporins contaminated with benzylpenicillin, 2) inclusion of in-vitro and retrospective studies not supported by skin testing, and 3) diagnosis of penicillin allergy based primarily on clinical history.
References:
Prior rates of 8-10% were an over estimation of the degree of cross-reactivity between beta-lactams due to 1) cephalosporins contaminated with benzylpenicillin, 2) inclusion of in-vitro and retrospective studies not supported by skin testing, and 3) diagnosis of penicillin allergy based primarily on clinical history.
References:
- Pichichero ME and Casey R. Safe use of selected cephalosporins in penicillin-allergic patients: A meta-analysis. Otolaryngology–Head and Neck Surgery. 2007;136:340-347.
- Macy E, Blumenthal KG. Are Cephalosporins Safe for Use in Penicillin
