This rate derived from early cross-reactivity studies seems to have been caused, at least partially, by contamination of early preparations of cephalosporins with trace amounts of penicillin G. A common myth is that about 10% of patients with a penicillin allergy history will experience an allergic reaction if administered a cephalosporin. Understanding the possible cross-reactivity will help a provider assess the risk to the patient and ultimately decide whether a nonpenicillin beta-lactam should be used.įor cephalosporins, the rate of cross-reactivity with penicillins is lower than previously believed. 3 If a patient’s penicillin allergy is determined by reaction severity or allergy testing to represent a true allergy, then the clinician is faced with the challenge of determining and interpreting the rate of allergic cross-reactivity from the penicillin class to the other beta-lactam classes (ie, cephalosporins, carbapenems, and mono-bactams). It is important to ascertain a patient’s reported reaction and reaction timing with regard to administration to help indicate whether the allergy represents an immunoglobin (IgE)-mediated reaction, a delayed-onset reaction, an adverse effect, or simply an intolerance. 1 This strategy will frequently lead to suboptimal regimens, including therapies that may be inferior to beta-lactam-based regimens or those that may have unnecessarily broad or inappropriately narrow spectrums of activity. Often, when patients are labeled as having a penicillin allergy, providers are forced to approach the scenario conservatively and simply avoid using beta-lactams. 2 Thus, with a true rate of penicillin allergy likely much lower than that reported by patients, health care professionals are often placed in a predicament regarding the selection of empiric antimicrobial therapy to treat a wide array of infectious conditions. 1 Primary reactions to penicillin antibiotics include rash, itching, nausea and vomiting, shortness of breath, and anaphylaxis.ĭespite the high population prevalence, 80% to 90% of those reporting a penicillin allergy will have a negative response to penicillin skin testing. Patient-reported allergy to penicillin antibiotics is a common scenario during health care encounters, with an estimated population prevalence of roughly 8% to 12%.
0 Comments
Leave a Reply. |