13536

Antonino Romano, MD

Cephalosporins are widely used antibiotics that can trigger IgE‑mediated immediate reactions and delayed hypersensitivity. The document outlines the clinical manifestations, diagnostic approaches, and natural history of these reactions, including the potential loss of sensitivity over time. It details skin testing and graded challenge protocols for patients with prior immediate reactions, and discusses risk assessment based on structural similarities of cephalosporin side chains. Cross‑reactivity with penicillins, carbapenems, and monobactams is examined, emphasizing the role of R1 and R2 side‑group similarities. Practical guidance for interpreting skin‑test results and selecting alternative β‑lactams is provided.