BACKGROUND: There have been few studies regarding the cross-reactivity and tolerability of penicillins, aztreonam, and carbapenems in large samples of subjects with cephalosporin allergy. OBJECTIVE: We sought to evaluate the possibility of using penicillins, monobactams, and carbapenems in subjects with cephalosporin allergy who especially require them. METHODS: We conducted a prospective study of 98 consecutive subjects who had 106 immediate reactions (mostly anaphylactic shock) to cephalosporins and had positive skin test results for these drugs. To assess the cross-reactivity with penicillins, monobactams, and carbapenems and the tolerability of such alternative β-lactams, all subjects underwent skin tests and serum-specific IgE assays with penicillin reagents, as well as skin tests with aztreonam, imipenem/cilastatin, and meropenem. Subjects with negative test results were challenged with meropenem, imipenem/cilastatin, aztreonam, and amoxicillin. RESULTS: Positive allergologic test results to penicillins were displayed by 25 (25.5%) subjects, including 1 with positive results to all reagents tested and another with a positive result to aztreonam. Another subject had positive results to both ceftazidime and aztreonam. A reaction to cephalosporins with side-chain structures similar or identical to those of penicillins was a significant predictor of cross-reactivity because of an increased 3-fold risk of positive results on allergologic tests with penicillin determinants. Challenges with alternative β-lactams were tolerated, with the exception of 1 urticarial reaction to imipenem/cilastatin. CONCLUSIONS: About 25% of subjects with cephalosporin allergy had positive results to penicillins, 3.1% to aztreonam, 2% to imipenem/cilastatin, and 1% to meropenem. In those who especially require alternative β-lactams, pretreatment skin tests are advisable because negative results indicate tolerability of the β-lactam concerned.
BACKGROUND: There have been few studies regarding the cross-reactivity and tolerability of penicillins, aztreonam, and carbapenems in large samples of subjects with cephalosporinallergy. OBJECTIVE: We sought to evaluate the possibility of using penicillins, monobactams, and carbapenems in subjects with cephalosporinallergy who especially require them. METHODS: We conducted a prospective study of 98 consecutive subjects who had 106 immediate reactions (mostly anaphylactic shock) to cephalosporins and had positive skin test results for these drugs. To assess the cross-reactivity with penicillins, monobactams, and carbapenems and the tolerability of such alternative β-lactams, all subjects underwent skin tests and serum-specific IgE assays with penicillin reagents, as well as skin tests with aztreonam, imipenem/cilastatin, and meropenem. Subjects with negative test results were challenged with meropenem, imipenem/cilastatin, aztreonam, and amoxicillin. RESULTS: Positive allergologic test results to penicillins were displayed by 25 (25.5%) subjects, including 1 with positive results to all reagents tested and another with a positive result to aztreonam. Another subject had positive results to both ceftazidime and aztreonam. A reaction to cephalosporins with side-chain structures similar or identical to those of penicillins was a significant predictor of cross-reactivity because of an increased 3-fold risk of positive results on allergologic tests with penicillin determinants. Challenges with alternative β-lactams were tolerated, with the exception of 1 urticarial reaction to imipenem/cilastatin. CONCLUSIONS: About 25% of subjects with cephalosporinallergy had positive results to penicillins, 3.1% to aztreonam, 2% to imipenem/cilastatin, and 1% to meropenem. In those who especially require alternative β-lactams, pretreatment skin tests are advisable because negative results indicate tolerability of the β-lactam concerned.
Authors: Jason A Trubiano; Cosby A Stone; M Lindsay Grayson; Karen Urbancic; Monica A Slavin; Karin A Thursky; Elizabeth J Phillips Journal: J Allergy Clin Immunol Pract Date: 2017-08-23
Authors: Gilbert Matte; Joseph Shuster; Chantal Guevremont; Phil Gold; Fabrice Leong; Zinquon Ngan; André Bonnici; Chris Tsoukas Journal: Can J Hosp Pharm Date: 2020-02-01