Penicillin Allergy in Pregnancy: Moving From "Rash" Decisions to Accurate Diagnosis

Group B Streptococcus in Pregnancy

To decrease risk of early-onset neonatal sepsis from group B streptococcus (GBS), pregnant patients should undergo screening between 36 0/7 and 37 6/7 weeks' gestation. Patients with a positive vaginal-rectal culture, GBS bacteriuria , or history of newborn with GBS disease should receive intrapartum antibiotic prophylaxis (IAP) with an agent targeting GBS. If GBS status is unknown at time of labor, IAP should be administered in cases of preterm birth, rupture of membranes for >18 hours, or intrapartum fever. The antibiotic of choice is intravenous penicillin; alternatives should be considered in cases of penicillin allergy depending on allergy severity.

Management of the Pregnant Patient with Beta-Lactam Allergy

PURPOSE OF REVIEW

We review the literature and discuss the logistics of testing pregnant patients for penicillin allergy.

RECENT FINDINGS

As in the general population, pregnant patients commonly report a penicillin allergy, but most patients are able to tolerate penicillin. Avoidance of beta-lactams in pregnancy is associated with increased morbidity: longer hospitalizations, more frequent infections, and more complications. Penicillin allergy testing is safe in pregnant patients, and obstetricians are eager for allergists to offer this procedure to their patients. As allergists, we can improve our patients' health outcomes by offering penicillin allergy testing in our practices. The protocols for testing both with and without skin testing in pregnant patients have been studied, and future studies will continue to clarify the safety and efficacy of penicillin allergy delabeling in pregnant patients.

Outpatient penicillin allergy evaluation during pregnancy and associated clinical outcomes

BACKGROUND

Beta-lactam antibiotics are often clinically indicated in the peripartum period, posing a challenge for pregnant women who report a penicillin allergy. Allergy verification testing is rarely performed during pregnancy even though most women do not have a true allergy.

OBJECTIVE

To evaluate a hospital-wide multidisciplinary program introduced in August 2020 to identify, refer, evaluate, and test pregnant women with unverified penicillin allergies, and assess its association with maternal and neonatal outcomes.

STUDY DESIGN

We conducted a retrospective cohort study at a large academic hospital of all pregnant women with a penicillin allergy documented in the electronic medical record who delivered from September 2020 to October 2021. Data were abstracted by chart review. Women referred for penicillin allergy evaluation were compared to those who were not. Maternal outcomes were alternative antibiotic (clindamycin or vancomycin) use, postpartum infection, and maternal length of postpartum hospital stay. Neonatal outcomes were intensive care unit admission, postnatal blood draw, antibiotic treatment, and birth hospitalization length of hospital stay. Bivariate and multivariable analyses were performed.

RESULTS

Of 689 women with a documented penicillin allergy, 232 (33.7%) were referred for allergy evaluation during the study period. Of those referred, 175 (75.4%) underwent allergy consultation and 167 (95.4%) of them were considered appropriate for allergy verification testing. 117 (70.1%) underwent skin testing with or without graded oral amoxicillin drug challenge, and all but one (99.1%) were found to be penicillin tolerant. Five additional women were de-labeled of their penicillin allergy based on history and pharmacy confirmation of penicillin tolerance subsequent to index reaction. Referred women had a 62% lower likelihood of receiving an alternative antibiotic than those who were not referred, and this significance persisted even after adjusting for potential confounders (aOR 0.49, 95% CI 0.27-0.89). Other maternal and neonatal adverse outcomes were less frequent in those referred, but these associations did not reach statistical significance.

CONCLUSION

This study documents the feasibility, safety, and clinical benefit of an outpatient penicillin allergy referral program for pregnant women. Referred patients were significantly less likely to receive alternative antibiotics, however, more patients are needed to assess whether there are additional clinical benefits.

Safety and outcomes of penicillin allergy evaluation in pregnant women

BACKGROUND

Penicillin allergy in pregnancy is associated with increased morbidity and the use of less effective antibiotics. Penicillin allergy evaluation in pregnancy is now recommended as per obstetrical guidelines but remains infrequent.

OBJECTIVE

We studied pregnant women who underwent penicillin allergy evaluation in an allergy clinic to assess the effectiveness and safety of penicillin skin testing (PST) and incremental drug challenge (IDC) in pregnancy.

METHODS

Index drug reactions, PST, and IDC results were reviewed. Antibiotic use, pregnancy outcomes, and pregnancy complications were compared with a control cohort of pregnant women with penicillin allergy who did not undergo allergy evaluation before delivery.

RESULTS

Penicillin allergy was evaluated in 136 women. Culprit drugs included penicillin (37%), amoxicillin (30%), and unknown (20%). Index reactions occurred greater than 5 years ago in 91%, and these reactions were cutaneous or unknown in 92%. Of the 133 patients who underwent skin testing, 131 (99%) had negative or equivocal results and proceeded to incremental challenge. All 131 women passed penicillin IDC. Of the 69 women who ultimately used intrapartum beta-lactam antibiotics, all but 1 patient tolerated them. Women who underwent penicillin allergy evaluation did not have an increased risk of cesarean delivery or other pregnancy complications when compared with women without penicillin allergy evaluation.

CONCLUSION

PST and IDC can be safely conducted in pregnant women. When evaluated as low risk, most women tolerate IDC and can receive penicillin intrapartum without adverse reactions or negative pregnancy outcomes.

Intrapartum and Postpartum Management of Intra-amniotic Infection

Importance

Intra-amniotic infection (IAI) is a common condition with potentially devastating maternal and neonatal complications. However, there are incomplete data regarding the most effective antimicrobial treatment regimen for this condition.

Objective

This article aims to review the current evidence and recommendations for intrapartum and postpartum management of IAI.

Evidence Acquisition

Original research articles, review articles, and guidelines on IAI were reviewed.

Results

Numerous known risk factors for IAI exist, some of which are modifiable. Serious neonatal complications can result from exposure to IAI including increased risk of preterm birth and neonatal death. Possible maternal complications include increased risk of cesarean delivery, postpartum hemorrhage, and postpartum endometritis. Antibiotics are the mainstay of treatment for IAI for both mothers and neonates, although there is no consensus on which antimicrobial agents are best and the appropriate duration of therapy.

Conclusions and Relevance

Monitoring patients for signs of IAI, proper treatment, and communication of the diagnosis with the pediatric team are essential for preventing maternal and neonatal complications of IAI. More research is needed to determine the proper treatment regimens for both mothers diagnosed with IAI and their neonates.

Outpatient Penicillin Allergy Testing in Pregnant Women Who Report an Allergy

Pregnant women are accepting of outpatient penicillin allergy testing, and most who report an allergy test negative.

OBJECTIVE:

To estimate the feasibility, acceptability, and safety of outpatient penicillin allergy testing among pregnant women.

METHODS:

We conducted a prospective cohort study at a large academic hospital from March 2019 to March 2020. We recruited pregnant women with a self-reported penicillin allergy who underwent allergy testing between 14 0/7 and 36 6/7 weeks of gestation.

RESULTS:

Of 127 eligible women pregnant women, 74 (58%, 95% CI 4–67%) accepted allergy testing. Fifty completed or intended to complete allergy testing, yielding a feasibility rate of 68% (95% CI 56–78%). Among the 46 women actually tested (who ranged in age from 18 to 42), 93% (95% CI 68–100%) had a negative test result. A systemic reaction (symptoms consistent with anaphylaxis) occurred in only 2 women (4%, 95% CI 0.5–15%) despite 20 (43%) reporting a severe allergy. No woman suffered an adverse event as a result of allergy testing. In multivariate analysis adjusting for age and parity, women with public insurance had decreased odds of undergoing penicillin allergy testing (adjusted odds ratio 0.24, 95% CI 0.08–0.69).

CONCLUSION:

Outpatient penicillin allergy testing is acceptable and feasible in pregnancy.