Tolerance of penicillin V in patients with confirmed delayed hypersensitivity reactions to aminopenicillins

Delayed drug hypersensitivity reactions have varied clinical phenotypes, from common maculopapular exanthem (MPE) to the rare but severe drug reaction with eosinophilia and systemic symptoms (DRESS).1 Few studies showed cross-reactivity between R1-side chains of aminopenicillins and aminocephalosporins in delayed (T-cell–mediated) hypersensitivity with tolerability for other penicillins and cephalosporins.2,3 We aim to describe a cohort of patients with confirmed delayed hypersensitivity to aminopenicillins who safely tolerate penicillin V, which has a different R1 side chain.