If a patient has a history of hives as an allergy to penicillin, which class of antibiotics can be safely used?

When considering an antibiotic option for a patient with a history of hives due to a penicillin allergy, it is essential to select a class that has a low risk of cross-reactivity with penicillins. Cephalosporins are related to penicillins structurally, and while there has been concern about cross-reactivity, current guidelines suggest that the majority of patients with a penicillin allergy can tolerate cephalosporins, particularly those that are less closely related to penicillins.

For a patient with a documented allergy to penicillin resulting in hives, using cephalosporins can often be considered safe, especially if they do not have a severe reaction—like anaphylaxis. However, careful selection of which cephalosporin is used is crucial, as first-generation cephalosporins have higher rates of cross-reactivity compared to later generations.

Tetracyclines and macrolides are also viable alternatives but they do not share the same structural concerns as cephalosporins. Aminoglycosides are another option that is generally safe as well, but their use is often limited based on specific infection types and dosing concerns.

Choosing cephalosporins can provide important therapeutic benefits