Rationale: There is lack of studies on cross reactivity of carbapenems and cephalosporins in patients with penicillin allergy, as well as on the negative predictive value of penicillin allergy evaluation in the Arabian Gulf countries.we sought to evaluate the use of carbapenems and cephalosporins in penicillin-allergic patients and clarify the negative predictive value of full allergy evaluation in an Arabian Gulf Country, Kuwait.
Methods: Allergy workup was performed on patients suspected of penicillin allergy from 2009 to 2014. Patients presenting with anaphylaxis or tested positive, were offered testing for meropenem and cephalosporin. Patients tested negative were contacted by phone to check subsequent betalactam intake.
Results: Out of 189 patients tested for betalactams, we had 76 (40.2%) with positive results. Among positive patients, we had 65 (85.5%) who presented initial reaction to penicillin and 25 (38%) of them were challenged with alternative medication with tolerance except for two patients; one to meropenem and one to cefuroxime. We had 11 (14.5%) who presented initial reaction to cephalosporin with tolerance to alternative medications. Phone calls to all 113 (59.8%) patients with negative betalactam testing showed that 17 (15%) took betalactams and 23 (20.3%) did not. Only 2 patients reported reaction but rejected retesting.
Conclusions: It is safe to administer carbapenems and cephalosporins to our patients with positive penicillin skin testing, by a graded challenge. Our calculated negative predictive value for penicillin testing is 88.2 to 100%, which is similar to other studies.