The Use of Perioperative Cephalexin in Penicillin Allergic Patients in Dermatologic Surgery: An Advisory Statement

Approximately 10% of patients report penicillin allergy. Based on historical guidelines, patients with a penicillin allergy should receive an alternative to cephalexin for prophylaxis in dermatologic surgery.

To determine, based on evidence, if cephalexin should be used as a first-line prophylactic antibiotic in dermatologic surgery for patients with penicillin allergy.

Systematic review of the literature was performed with defined search terms.

Less than 5% of those with penicillin allergy labels have a true penicillin allergy. For patients with true, persistent penicillin allergy, there is an overall low cross-reactivity with cephalosporins, especially with cephalosporins that do not share identical R1 side chain. The first-generation cephalosporins, including cephalexin, have a slightly higher risk of cross-reactivity in patients with reported allergy to amino-penicillins (amoxicillin, ampicillin) but not other penicillins. The risk of severe cross-reactivity of cephalosporins in patients with low-risk penicillin allergies is extremely low. Cephalexin has a superior side effect profile and efficacy compared to alternatives.

Cephalexin should be used as the first-line prophylactic antibiotic in dermatologic surgery for patients with documented penicillin allergy, including anaphylaxis. There may be a higher risk of cross-reactivity with cephalexin in patients with a confirmed amino-penicillin allergy.