J Allergy Clin Immunol 2015 Sep; 136:685
IgE mediated cephalosporin allergy (urticaria, angioedema, bronchospasm, anaphylactic shock) is caused by the abx side chain, but little is known about cross-reactivity.
n = 102 patients with history of cephalosporin allergy at Italian allergy clinics
All patients underwent PO and skin challenges with PCN, ampicillin, amoxicillin and 11 cephalosporins.
Cross-reactivity occurred within a group of cephalosporins with common side chains:
and between a group:
Patients with allergies to one group generally tolerated the other group.
Cefazolin was generally tolerated by all.
Take Away: PCN-allergic can tolerate cephalosporins, pts with cephalosporin allergy can generally tolerate a cephalosporin with a different side chain. However, skin tested or graded challenge is recommended prior to Rx.