Cephalosporins are often avoided in patients labeled with penicillin allergy due to potential cross-reaction. We describe the utility of an oral cephalosporin test dose in patients with penicillin allergy.Method:
A retrospective review of all inpatients labeled with penicillin allergy who received a single oral cephalosporin dose, identified through the pharmacy records between April 1, 2004 and October 30, 2008.Results:
Ninety-seven inpatients met our selection criteria. Type of penicillin reaction was described as rash/hives/pruritis, anaphylaxis, angioedema, and unknown in 53 (54.7%), 10 (10.3%), 7 (7.2%), and 27 (27.8%) cases, respectively. The test dose used was cephalexin 250 mg (56.7%) or 125 mg (35.1%) and cefuroxime axetil 125 mg (8.2%). Reaction to the test dose was noted in 5 (5.2%) patients, including rash (n=2), breathing difficulty (n=2), and asymptomatic eosinophilia (n=1). Breathing difficulty resolved with diphenhydramine/corticosteroids in one case and without any therapy in the other. Cephalosporin therapy was initiated within 3 hours (interquartile range, 2-6 hours) after test dose in 90/93 patients without test-dose reaction. Two (2.2 %) patients developed reaction during treatment: rash (n=1) and angioedema (n=1). One case complained of anxiety, and therapy was interrupted. Test-dose and treatment reactions were transient and easily managed.Conclusions:
An oral cephalosporin test dose was safe in patients labeled with penicillin allergy and predicted subsequent cephalosporin tolerance in nearly 90% of patients.