Immediate allergic reactions to cephalosporins and penicillins and their cross‐reactivity in children

Abstract
Penicillins and cephalosporins are the most important betalactams inducing IgE‐mediated reactions. The safety of administering cephalosporins to penicillin‐allergic children is a particular problem, because cephalosporin allergenic determinants have not been properly identified. A study was undertaken to evaluate the frequency of anaphylactic reactions to cephalosporins and penicillins and their cross‐reactivity in a pediatric population. A prospective survey was conducted in a group of 1170 children with suspected immediate allergic reactions to cephalosporins and/or penicillins, which were examined during a period of 8 yr.In vivo(skin tests and challenges) andin vitrotests (for specific IgE) were performed with standard concentration of penicillins and cephalosporins. When 1170 children with a clinical history of allergy to penicillins and/or cephalosporins were testedin vivofor immediate hypersensitivity to betalactams, 58.3% cases overall were found to be skin or challenge test positive. Among them, 94.4% patients were positive to penicillins and 35.3% to cephalosporins. The frequency of positive reactions in thein vivotesting was in the range from 36.4% to 88.1% for penicillins and from 0.3% to 29.2% for cephalosporins. However, 31.5% of the penicillin allergic children cross‐reacted to some cephalosporin. If a child was allergic to a cephalosporin, the frequency of positive reactions to penicillin was 84.2%. The cross‐reactivity between cephalosporins and penicillins varied between 0.3% and 23.9%. The cross‐reactivity among different generations of cephalosporins varied between 0% and 68.8%, being the highest for first and second‐generation cephalosporins and 0% for third generation cephalosporins. The frequency of immediate allergic reactions to cephalosporins is considerably lower compared to penicillins, and the degree of cross‐reactivity between cephalosporins and penicillins depends on the generation of cephalosporins, being higher with earlier generation cephalosporins. The cross‐reactivity among cephalosporins is lower compared to cross‐reactivity between penicillins and cephalosporins.