Title: Cross-reactivity between penicillins and cephalosporins: Clinical and immunologic studies
Abstract: Nineteen well-characterized penicillin-allergic patients were investigated for their seasitivity to cephalosporins containing potentially cross-reactive side chains.All patients were administered cephamandole parenterally and, if this was tolerated, a course of oral cephaloridine was administered.Only two patients responded to the cephamandole; none of the remaining patients reacted to cephaloridine.Benzylpenicilloyl RAST-inhibition studies with sera from three subjects who had not reacted to the cephalosporins demonstrated that cephamandole linked to proteins was capable of recognizing benzylpenicilloyl-specific IgE antibody.it is concluded that consideration of side chain structures can help to predict possible cross-reactions between penicillins and cephalosporins, but carefully controlled challenge tests are advisable before penicillin-allergic patients are treated with cephalosporins.In relation to cross-reacting potential, in vitro experimental studies are d#icult to interpret and may in some circumstances overestimate the risk.(J ALLERGY CLIN IMMUNOL 1989;83:381-5.)The penicillins are a major and widely used group of antibiotics containing a p-lactam structure.With their extensive use and the high doses that can be administered, they can be considered relatively nontoxic.The major adverse effects noted are the development of allergic reactions.A widely quoted world survey' suggested that the incidence of such reactions varied from 0.7% to 10% of treated patients.Cephalosporins, which also contain a p-lactam structure, have also caused allergic reactions, but it is often difficult to establish if a primary reaction to the cephalosporins is occurring or whether a cross-reaction in a penicillin-allergic subject is involved.'Studies have demonstrated that penicillin-allergic subjects are at more risk for a reaction to a cephalosporin than nonpenicillin allergic subjects,3, 4 but the incidence varies depending on the stringency of the criteria applied to