Penicillin Allergy Assessment in Pregnancy: Safety and Impact on Antibiotic Use

Abstract

Background: Penicillin and other beta-lactam antibiotics are recommended for group B Streptococcus and cesarean section prophylaxis, but approximately 10% of pregnant patients report a penicillin allergy.

Objective: To assess the safety and impact of penicillin allergy evaluation in pregnant patients.

Methods: In this retrospective study of obstetrician-ordered Allergy/Immunology (AI) electronic consultations (e-consults) from September 20, 2017 through December 31, 2019, we reviewed the electronic health record for e-consult recommendation; patient demographic, obstetric, and allergy histories; and peripartum antibiotic utilization with indication. For patients whose electronic consultation recommended an in-person AI evaluation, testing outcomes were determined, and multivariable logistic regression models were used to compare antibiotic use between patients who did and did not receive an in-person AI evaluation.

Results: Of 389 obstetrician-ordered e-consults, 363 (93%) recommended an in-person AI evaluation; of these, 222 (61%) patients received an in-person AI evaluation. Of 220 (99%) patients skin tested, 209 (95%) had their penicillin allergy label safely removed. Compared with patients who did not receive an in-person AI evaluation despite it being recommended (n = 141), patients with in-person AI evaluation (n = 222) had reduced peripartum vancomycin (adjusted odds ratio [aOR], 0.07; 95% CI, 0.01-0.33), clindamycin (aOR, 0.17; 95% CI, 0.08-0.34), and gentamicin (aOR, 0.39; 95% CI, 0.19-0.78) use and increased penicillin (aOR, 18.0; 95% CI, 6.30-51.2) use. The fully AI evaluated patients had increased first-line antibiotic prophylaxis for group B Streptococcus (aOR, 26.9; 95% CI, 6.32-114) and cesarean section (aOR, 1.94; 95% CI, 1.06-3.52).

Conclusions: In a sample of 220 pregnant patients with penicillin allergy histories and in-person AI evaluation, penicillin allergy testing was safe and associated with significantly reduced broad-spectrum antibiotic use and increased first-line beta-lactam antibiotic use.

Keywords: Adverse drug reaction; Antibiotic; C-section; Cephalosporin; Drug challenge; E-consult; Group B Streptococcus; Hypersensitivity; Penicillin; Skin test; Stewardship; Telemedicine.

Figure 1.

Flow chart of Allergy/Immunology (AI) e-consults and In-Person Consults for Obstetric Patients with Reported Penicillin Allergy * 1 patient with selective aminopenicillin allergy and 1 patient delabeleld based on history ^†1 patient had a recent reaction and 1 patient had severe cutaneous adverse reaction; these reactions were not appropriately documented in the electronic health record. ^‡1 patient with positive intradermal test to ampicillin, 1 patient with positive intradermal test to benzylpenicilloyl polylysine, and 1 patient with subjective symptoms (sensation of throat/tongue swelling) during skin testing ^¶2 patients deferred challenge due to anxiety, 2 physicians deferred challenge due to recent or severe reactions not known from documentation in the electronic health record. Abbreviations: AI, Allergy/Immunology; e-Consult, electronic consult

Figure 2.

Antibiotic Utilization in Obstetric Patients with Reported Penicillin Allergy. This figure demonstrates antibiotic use and its associated timing (pregnancy, delivery, post partum) for each group of obstetric patients who received an e-consult. Beta-lactams, beta-lactam alternatives, and both are indicated by color according to the frequency of their use. Abbreviations: AI, Allergy/Immunology; e-Consult, electronic consult

Figure 3.

Antibiotic Utilization for Group B Streptococcus and C-Section Prophylaxis in Obstetric Patients with Reported Penicillin Allergy. This figure demonstrates patients who ultimately had GBS or C-sections with their associated antibiotic use. *Penicillin for Group B Strep and cefazolin for C-section surgical site infection prophylaxis Abbreviations: AI, Allergy/Immunology; e-Consult, electronic consult; Group B Strep, Group B Streptococcus; C-section, Caesarian section.