Patients with Allergies to One Cephalosporin Often Can Tolerate Others

David J. Amrol, MD reviewing Romano A et al. J Allergy Clin Immunol 2015 Sep.

Cephalosporin hypersensitivity does not seem to be a class hypersensitivity.

Cephalosporins can cause IgE-mediated allergic reactions, which are characterized by urticaria, angioedema, bronchospasm, and anaphylactic shock, typically within 1 hour. Studies suggest that allergy to cephalosporins is mediated by their molecular side chains, but we know little about cross-reactivity among different cephalosporins.

Researchers at two Italian allergy clinics evaluated 102 patients with histories of cephalosporin allergies. All patients underwent oral challenges and skin testing to penicillin, ampicillin, amoxicillin, and 11 cephalosporins. Cross-reactivity occurred within a group of cephalosporins that have a common side chain (cefuroxime, ceftriaxone, cefotaxime, cefepime, and ceftazidime) and within a group consisting of ampicillin and two aminocephalosporins (cefaclor and cephalexin). Patients who were allergic to cephalosporins in one group generally tolerated drugs from the other group. Cefazolin typically was tolerated by patients with allergies to cephalosporins in either group.

Citation(s):

Romano A et al. IgE-mediated hypersensitivity to cephalosporins: Cross-reactivity and tolerability of alternative cephalosporins. J Allergy Clin Immunol 2015 Sep; 136:685.