Abstract
Purpose :
In the US, up to 10% of the general population has a reported penicillin (PCN) allergy. The mainstay treatment of bacterial endophthalmitis is intravitreal vancomycin and ceftazidime. Despite the low cross-reactivity between beta-lactams and later-generation cephalosporins, many providers still alter their approach due to concern for allergic reaction. We evaluated the management strategies of infectious endophthalmitis in the setting of systemic allergies to standard intravitreal antibiotics.
Methods :
This was a single-center, retrospective cohort study of patients with endophthalmitis between 2005 - 2019. Included were patients with a documented beta-lactam, cephalosporin or vancomycin allergy who received intravitreal antibiotics based on ICD9, ICD 10, and CPT codes. Baseline findings, allergic reactions, and anatomic outcomes were analyzed.
Results :
Of 483 patients with endophthalmitis, 47 (9.7%) had a documented allergy to beta-lactam and/or cephalosporin antibiotics. One patient (2.1%) had a concurrent vancomycin and beta lactam allergy. The most common causes of endophthalmitis were post cataract surgery (n=14; 30%) and post injection (n=10; 21%). Ninety-eight percent (46/47) received intravitreal vancomycin and 77% (36/47) ceftazidime. Of the 36 patients who received ceftazidime, 78% (28/36) had a documented PCN allergy and 14% (5/36) a cephalosporin allergy. None of these patients experienced an allergic reaction after intravitreal ceftazidime. The one patient with a vancomycin allergy received intravitreal vancomycin and did not exhibit an allergic reaction.
Eleven of 47 patients (23%) did not receive ceftazidime. Of these, 54.5% (6/11) had a prior anaphylactic reaction or difficulty breathing to PCN but not to a cephalosporin. Six of these 11 patients (55%) received intravitreal amikacin. The overall rate of a retinal detachment in patients treated with intravitreal ceftazidime was 8% (3/36) compared to 36% (4/11) in those without ceftazidime (p = 0.04).
Conclusions :
In this retrospective study of endophthalmitis patients with systemic antibiotic allergies, there were no documented allergic reactions after administering a similar intravitreal antibiotic. Ophthalmologists should employ evidence-based practices when choosing antibiotics for infectious endophthalmitis in antibiotic-allergic patients.
This is a 2020 ARVO Annual Meeting abstract.