Answer:
The beta-lactam ring, the thiazolidine/dihydrothiazine ring and the side-chains are all potentially immunogenic. Cross-reactivity between penicillin and third-generation cephalosporins occurs in 2% to 3% of penicillin-allergic patients.
This is one of the answers.
The second is
The cephalosporin medications that are likely to cross-react after penicillin allergies have been established and include: Cephalexin. Cefadroxil. Ceflaclor.
