Patients with penicillin allergy are not necessarily allergic to cephalosporins.
Use of cephalosporins for treatment of pediatric infections is limited because of concern about cross-reactivity in patients with penicillin allergy. In an industry-supported review, researchers examined the evidence from 44 studies on cephalosporin cross-reactivity in patients allergic to penicillin (J Am Pharm Assoc 2008; 48:530).
About 10% of patients in the general population report allergic responses to penicillin and the reported risk for anaphylactic reaction to cephalosporins ranges from 1:1000 to 1:1,000,000, but this risk is increased fourfold in patients with penicillin allergy. Characteristics of adverse drug reactions (immunologic, nonimmunologic, duration, severity) are key to distinguishing allergic from nonallergic adverse re…