Documented Penicillin Allergy Research Articles

Cefazolin as the mainstay for antibiotic prophylaxis in patients with a penicillin allergy in obstetrics and gynecology

Cefazolin is the most common antibiotic used for prophylaxis in obstetrics and gynecology. Among those with a penicillin allergy, alternative antibiotics are often chosen for prophylaxis given fears of cross-reactivity between penicillin and cefazolin. Alternative antibiotics in this setting are associated with adverse sequalae including surgical site infection, induction of bacterial resistance, higher costs to the healthcare system, and possible Clostridium difficile infection. Given the difference in R1 side chains between the penicillin and cefazolin, cefazolin use is safe and should be recommended for penicillin allergic patients including those who experience IgE-mediated reactions such as anaphylaxis. Cefazolin should only be avoided in those who experience a history of a severe, life-threatening delayed hypersensivity reaction manifested as severe cutaneous adverse reactions (Steven-Johnson Syndrome), hepatitis, nephritis, serum sickness, and hemolytic anemia in response to penicillin administration. Additionally, over 90% of those with a documented penicillin allergy do not have true allergy on skin testing. Increased referral for penicillin allergy testing should be incorporated into routine obstetric care and preoperative assessment to reduce suboptimal antibiotic prophylaxis use. More education is needed among providers surrounding penicillin allergy assessment and cross-reactivity among penicillins and cephalosporins to optimize antibiotic prophylaxis in obstetrics and gynecology.

Impact of penicillin allergy records on antimicrobial prescribing in hospitalised patients

The overdiagnosis of penicillin allergy and misclassification of non-truly allergic reactions is a growing public health problem, associated with the overuse of broad-spectrum and restricted antimicrobials. We aimed to evaluate the impact of penicillin allergy status on antimicrobial prescribing. A retrospective study of inpatients with a documented penicillin allergy receiving antimicrobials was conducted from 1 April to 1 July 2021. Antimicrobial prescribing and clinical characteristics were compared between patients with an active penicillin allergy label and those whose label was removed following antimicrobial stewardship team review. Antimicrobials were classified in two categories: i) 'Access' (recommended), ii) 'Watch and Reserve' (restricted) according to WHO AWaRe classification, a tool to guide appropriate antibiotic use. 437 patients with a documented penicillin allergy receiving antimicrobials were included. 353 patients with an active penicillin allergy label, more frequently received antimicrobials from the 'Watch and Reserve list' (283;80% vs 30;37%; p<0.001). In contrast, 84 patients who were de-labelled received more often antimicrobials from the 'Access list' (53;63% vs 64;18%; p<0.001). Penicillin allergy reviews and de-labelling strategies may reduce the use of restricted antimicrobials under the 'Watch and Reserve list'. This practice should be encouraged and reinforced in all hospitals.

Assessing the rationale of prescribing carbapenems among hospitalized patients with documented penicillin allergy: implications for stewardship.

A reported history of penicillin allergy frequently leads to the prescription of carbapenems as a substitute for penicillin to avoid allergic reactions. Such self-reported allergies need to be accurately characterized to identify targeted antibiotic stewardship interventions that potentially minimize unnecessary carbapenem use. Retrospective cohort study. The proportion of hospitalized patients with penicillin allergy history receiving carbapenem prescriptions was evaluated between January 1st, 2017 and December 31st, 2018 at the University Hospital Basel, Switzerland. The appropriateness of carbapenem prescription of each patient was evaluated using institutional guidelines based on previously published recommendations. Our analysis revealed that among 212 patients with recorded penicillin allergy, of the 247 carbapenem treatment episodes, 79 (32%) were unjustified. Abdominal and lower respiratory tract infections were most frequently associated with inappropriate carbapenem use (OR 2.64, 95% CI 1.22-5.71, P = .014 and OR 2.26, 95% CI 1.08-4.73, P = .031). The recorded allergy type was not documented or unclear in 153 patients (72%) and penicillin allergy was only confirmed in 2 patients (0.9%). Inconsistencies in allergic symptom documentation and allergy types were found between the institution's two software programs. While a multimodal approach to identify and accurately label penicillin allergies remains essential to reduce inappropriate carbapenem use, our findings highlight the need for comprehensive and easily accessible guidelines for carbapenem utilization and structured history-based allergy assessment as an initial screening tool, embedded in a tailored digital allergy record template.

1837. Evaluation of Disparities in Beta-Lactam Allergies and Subsequent Antibiotic Use in Outpatients with Acute Bacterial Skin and Skin Structure Infections

Abstract Background Black patients with skin and soft tissue infections are more likely to have a documented penicillin allergy and use of non-beta-lactams than white patients. We sought to compare the prevalence and risk factors for documented beta-lactam allergy (D-BLA) among racial and ethnic minorities (REM) and white patients and beta-lactam (BL) use for outpatient Acute Bacterial Skin and Skin Structure Infections (ABSSSIs). Methods We conducted a cohort study of adult outpatients (18-90 years) seen by the Texas Tech University Health Science Center Physicians group (2012-2021). All patients had an ICD-9 or ICD-10 code for an ABSSSI in the primary or secondary position. Descriptive statistics were reported. Logistic regression models were used to determine which factors were statistically associated with D-BLA and which factors were associated with BL use for the ABSSSI. Multivariable (MV) analysis results were reported as odds ratios (OR) and 95% confidence intervals (95%CI). All analyses were conducted in R. Results REM represented 38% of the 21,673 patients in the cohort. A D-BLA was present for 18% percent of all patients and was higher in white patients than REM (22 vs 13%). Factors associated with D-BLA on MV analysis of the total cohort were age (OR 1.01 per year, 95%CI 1.01-1.01), Medicaid (OR 1.18, 95%CI 1.04-1.34), or Medicare (OR 1.17, 95%CI 1.05-1.31). Factors associated with a lower likelihood of D-BLA on MV analysis of the entire cohort were REM (OR 0.55, 95%CI 0.51-0.60) and male sex (OR 0.56, 95%CI 0.52-0.60). Regarding BL use, white patients were less likely to receive a BL than REM (26 vs 30%). Factors associated with a reduced likelihood of BL use on MV analysis of the total cohort were D-BLA (OR 0.60, 95%CI, 0.54-0.67), Medicaid (OR 0.83, 95%CI 0.74-0.93), or Medicare (OR 0.64, 95%CI 0.58-0.70). Factors associated with BL use on MV analysis of the entire cohort were REM (OR 1.20, 95%CI 1.12-1.28), male sex (OR 1.45, 95%CI 1.36-1.54), or self-pay (OR 1.52, 95%CI 1.37-1.68). The interaction term between REM and D-BLA was not significant for BL use. Conclusion REM were at a reduced risk of a D-BLA in our cohort and were more likely to receive a BL for ABSSSIs. Payor status and sex also significantly impacted rates of D-BLA and BL use. Disclosures Ronald G. Hall, II, PharmD, MSCS, Merck: Grant/Research Support Carlos Alvarez, PharmD, MSc, MSCS, Boehringer Ingelheim: Grant/Research Support|Bristol Myer Squibb: Grant/Research Support|Merck: Grant/Research Support

A new clinical opportunity: Rechallenging penicillin allergy in an outpatient pharmacy

In the United States, approximately 27 million people have a documented penicillin allergy, but 90% of the allergies are falsely labeled. By rechallenging suspected allergies, a pharmacist can optimize patient care, fulfill antimicrobial stewardship objectives, and educate patients on true allergies. We suggest a protocol that allows pharmacists to investigate the presence of an allergy and conduct a challenge when indicated. The protocol consists of a patient interview, a risk assessment, an oral rechallenge, and the potential for a skin test. The testing and delabeling of penicillin allergies will enhance the practice of antimicrobial stewardship in the outpatient setting. In the changing landscape of pharmacy, community pharmacists can increase their services and improve patient care. Owing to limited documented experience in the outpatient pharmacy, an opportunity to set the standard and be a leader in the field is present.

Documented Penicillin Allergies on Antibiotic Selection at Pediatric Emergency Department Visits.

Penicillin or amoxicillin are the recommended treatments for the most common pediatric bacterial illnesses. Allergies to penicillin are commonly reported among children but rarely true. We evaluated the impact of reported penicillin allergies on broad-spectrum antibiotic use overall and for the treatment of common respiratory infections among treat-and-release pediatric emergency department (ED) visits. Retrospective cohort study of pediatric patients receiving antibiotics during a treat-and-release visit at a large, pediatric ED in the northeast from 2014 to 2016. Study exposure was a reported allergy to penicillin in the electronic medical record. Study outcomes were the selection of broad-spectrum antibiotics and alternative (second-line) antibiotic therapy for the treatment of acute otitis media (AOM) and group A streptococcus (GAS) pharyngitis. We used unadjusted and adjusted generalized estimating equation models to analyze the impact of reported penicillin allergies on the selection of broad-spectrum antibiotics. We used unadjusted and adjusted logistic regression models to determine the probability of children with a documented penicillin allergy receiving alternative antibiotic treatments for AOM and GAS. Among 12,987 pediatric patients, 810 (6.2%) had a documented penicillin allergy. Penicillin allergies increased the odds of children receiving a broad spectrum versus narrow spectrum antibiotic (adjusted odds ratio, 13.55; 95% confidence interval (CI), 11.34-16.18). In our adjusted logistic regression model, the probability of children with a documented penicillin allergy receiving alternative antibiotic treatment for AOM was 0.97 (95% CI, 0.94-0.99) and for GAS was 0.97 (95% CI, 0.92-0.99). Antibiotic stewardship efforts in pediatric EDs may consider the delabeling of penicillin allergies particularly among children receiving antibiotics for an acute respiratory infection as a target for intervention.

Impact of antimicrobial stewardship interventions on peripartum antibiotic prescribing in patients with penicillin allergy

Beta-lactam antibiotics (eg, penicillins, cephalosporins, and carbapenems) are preferred for group B streptococcus prophylaxis, intra-amniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection and longer lengths of stay. Most patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross-reactivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed. This study aimed to evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peripartum indications in patients with a reported penicillin allergy, following updates to institutional guidelines. This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at 2 hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1, 2018, and October 31, 2018 (preintervention group) and May 1, 2020, to October 31, 2020 (postintervention group). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetrical prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. The secondary measures included maternal and neonatal outcomes. A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the preintervention group and 96 patients in the postintervention group). Hives were the most commonly reported index symptom in both groups (40/96 [41.7%] vs 39/96 [40.6%]; P=.883). After stewardship interventions, there was a significant increase in the rate of preferred antibiotic use (33/96 [34.3%] vs 81/96 [84.3%]; P<.001). The effect was the greatest in patients with nonsevere allergy (14/76 [18.4%] vs 68/82 [82.9%]; P<.001). There was no difference in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre- and postintervention groups. Of note, 1 patient in the postintervention group experienced itching, and another patient developed a rash, both of which resolved with medical management. A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.

In-Office Amoxicillin to Increase Graded-Dose Challenges at Initial Evaluation for Penicillin Allergy.

More than 90% of pediatric patients labeled with a penicillin allergy can tolerate subsequent treatment courses without reaction. Graded-dose challenges (GDCs) are an important tool to clarify reported penicillin allergy. To increase the use of same-day amoxicillin GDCs among patients with a low-risk penicillin allergy history who presented for outpatient allergy office evaluation from 2% to 15% and sustain for 6 months. New patients evaluated in an academic pediatric allergy clinic with a documented penicillin allergy were included, regardless of reason for referral. The percentage of these patients who were administered a GDC to amoxicillin at the initial evaluation was assessed over time. Multiple interventions were implemented to increase same-day GDC: amoxicillin, previously only available from pharmacy, was made available in clinic, and penicillin-allergic patients were scheduled earlier in the clinic session. The baseline rate of new patients with penicillin allergy who received a GDC increased from 2% to 18% after amoxicillin was stocked in the allergy clinic. GDCs further increased to 34% after penicillin-allergic patients were scheduled at a time conducive to challenge. Amoxicillin availability in the clinic setting increased the percentage of eligible patients who completed same-day GDCs. Scheduling adjustments further increased the ability to conduct GDCs. Proactive penicillin allergy delabeling efforts can be assisted through practical approaches in the outpatient setting.

Pregnant Patients with a Documented History of Penicillin Allergy and Associated Maternal and Neonatal Outcomes at a Tertiary Care Center.

Pregnant individuals are likely to need antibiotics during the peripartum period. For pregnant individuals who report a history of penicillin allergy, non-β-lactam antibiotics are often administered. Compared with first-line β-lactam antibiotics, alternative antibiotics can be less effective, more toxic, and more costly. It remains unclear if being labeled with a penicillin allergy is associated with adverse maternal and neonatal outcomes. We conducted a retrospective cohort study of all pregnant patients who delivered a viable singleton between 24 and 42 weeks of gestation at a large academic hospital from 2013 to 2021. We compared patients who had a documented penicillin allergy history in their electronic medical record versus those who did not and examined whether there were significant differences in maternal outcomes and neonatal outcomes. Bivariable and multivariable analyses were performed. Of 41,943 eligible deliveries included in the analysis, 4,705 (11.2%) patients had a penicillin allergy history documented in their electronic medical record and 37,238 (88.8%) did not. Even after adjusting for potential confounders, patients with a documented penicillin allergy had a higher risk of postpartum endometritis (adjusted odds ratio [aOR]: 1.46; 95% confidence interval [CI]: 1.01-2.11) and a higher risk of their neonates having a postnatal hospital stay lasting more than 72 hours (aOR: 1.10; 95% CI: 1.02-1.18). There were no significant differences seen in the other maternal and neonatal outcomes in both bivariable and multivariable analyses. Pregnant patients who are labeled as having a penicillin allergy are more likely to have postpartum endometritis, and neonates born to mothers who are labeled as having a penicillin allergy are more likely to have a postnatal hospital stay lasting more than 72 hours. There were no other significant differences seen in pregnant patients and their newborns whether they were labeled as having a penicillin allergy history or not. However, pregnant individuals with a penicillin allergy documented in their medical record were significantly more likely to receive alternative non-β lactam antibiotics, and may have benefitted from having more details of their allergy history available as well as proper allergy verification with testing. · It is unclear whether pregnant individuals labeled with penicillin allergies have worse obstetric outcomes.. · These individuals were significantly more likely to have endometritis and their newborns hospitalized for >72 hours.. · They were significantly more likely to receive alternative non-β lactam antibiotics than those without documented allergies..

Microbiologic and Clinical Description of Postoperative Central Nervous System Infection After Endoscopic Endonasal Surgery

Consensus guidelines for antibiotic prophylaxis in endoscopic endonasal surgery (EES) have not been developed. The study objective was to define the microbiologic and clinical characteristics of post-EES central nervous system (CNS) infections. This was a single-center retrospective study of patients >18 years of age who underwent EES between January 2010 and July 2021 at a high-volume skull base center. Patients with confirmed CNS infection within 30 days of EES were included. During the study period, the standard prophylaxis regimen was ceftriaxone 2 g every 12 hours for 48 hours. For patients with a documented penicillin allergy, vancomycin plus aztreonam was recommended. In total, 2440 EES procedures were performed on 2005 patients; the CNS infection rate was 1.8% (37/2005). CNS infections were more common among patients with a history of previous EES (6.5%; 20/307) compared with those who did not (1%; 17/1698; P < 0.001). The median time from EES to CNS infection was 12 (6-19) days. Thirty-two percent (12/37) of CNS infections were polymicrobic, which was more common among patients without previous EES (52.9%; 9/17) compared with those with previous EES (15%; 3/20; P= 0.03). Across all cases, Staphylococcus aureus (n= 10) and Pseudomonas aeruginosa (n= 8) were commonly isolated pathogens. Among those with confirmed methicillin-resistant Staphylococcus aureus (MRSA) nares colonization before EES, 75% (3/4) developed MRSA CNS infections compared with 6.1% (2/33) of noncolonized patients (P= 0.005). CNS infection after EES is rare and causative pathogens vary. Further studies are needed to identify the impact of MRSA nares screening on antimicrobial prophylaxis before EES.

A potential cost savings analysis of a penicillin de-labeling program.

Over 95% of patients documented as penicillin allergic can tolerate a penicillin without a reaction. Inaccurate documentation of penicillin allergy leads to more expensive alternative antibiotic prescriptions and an increased incidence of resistant infections. To understand the potential drug cost savings of a penicillin de-labeling program to a healthcare system. We evaluated patient visits with documented penicillin allergy who presented to the pediatric Emergency Department (PED) and 22 associated primary care clinics. Patients were included if they were discharged home with a non-penicillin antibiotic when the first-line treatment for the diagnosis would have been a penicillin. The potential cost savings were the sum of all visit-level cost differences between the non-penicillin prescription(s) and a counterfactual penicillin prescription. To factor in a 95% successful patient de-labeling rate, we repeatedly sampled 95% from the patients with the eligible visits 10,000 times to produce an estimate of the potential cost savings. Over the 8-year period, 2,034 visits by 1,537 patients to the PED and 12,349 visits by 6,073 patients to primary care clinics satisfied eligibility criteria. If 95% of the patients could have been successfully de-labeled, it would have generated a cost saving of $618,653 (95% CI $618,617-$618,689) for all the corresponding payers in the system. Implementing a penicillin de-labeling program across a healthcare system PED and its associated primary care clinics would bring significant cost savings. Healthcare systems should rigorously evaluate optimal methods to de-label patients with reported penicillin allergy.

Impact of a Documented Penicillin Allergy on Antibiotic Selection in Pediatric Patients With Osteomyelitis.

Penicillin allergy labels are common in hospitalized patients, and there is a frequent misconception that these patients cannot receive cephalosporins. Through retrospective review, we found that patients with reported penicillin allergies were significantly less likely to receive first-line therapy for acute hematogenous osteomyelitis.

Documented Penicillin Allergies Should Not Preclude Use of Preoperative Cefazolin in Hip and Knee Arthroplasty

Perioperative cefazolin administration for total joint arthroplasty is a first-line antibiotic recommended by the American Academy of Orthopaedic Surgeons (AAOS) guidelines for the prevention of periprosthetic joint infections (PJIs). We aim to analyze the clinical viability of giving patients with a documented penicillin allergy (PA) a perioperative full-strength cefazolin "test dose" under anesthesia. This is a retrospective chart review of 2,451 total joint arthroplasties from a high-volume arthroplasty orthopaedic surgeon over a 5-year period from January 2013 through December 2017. This surgeon routinely gave patients with a documented PA a full-strength cefazolin test dose while under anesthesia instead of administrating a second-line antibiotic. The primary outcomes examined were allergic reaction and postoperative infection. Cefazolin was given to 87.1% of all patients (1,990) and 46.0% of patients with a PA (143). The total rate of allergic reactions among all patients was 0.5% (11). Only one patient with a documented PA who received cefazolin had an allergic reaction. The reaction was not severe and did not require any additional treatment. In patients who had no reported allergies and received cefazolin, 0.3% (6) had an allergic reaction. There was no statistically significant difference in the rate of allergic reaction when comparing patients with and without a PA (P = 0.95). Patients receiving cefazolin had an overall PJI rate of 2.9% (57) versus those patients receiving antibiotics other than cefazolin who sustained a 5.5% PJI rate (16), which was statistically significant (P = 0.02). This study found that utilization of a full-strength test dose of cefazolin in patients with a documented PA is a feasible, safe, and effective way of increasing the rate of cefazolin administration and thus mitigating the risk of PJIs.

1662. Impact of a Documented Penicillin Allergy on Antibiotic Selection in Patients with Osteomyelitis

Abstract Background Penicillin allergy is the most commonly reported drug allergy, affecting approximately 10% of patients. Although historically there has been concern about administering cephalosporins to patients allergic to penicillin, the rates of cross-reactivity are only approximately 2%. As cephalosporins are the first-line and safest treatment for many infections, unnecessary avoidance of cephalosporins places patients at risk of poor disease outcomes and antibiotic-associated harms. We assessed the relationship between penicillin allergy label and antibiotic selection in pediatric patients with acute osteomyelitis. Methods We performed a retrospective review of inpatients at our quaternary children’s hospital diagnosed with osteomyelitis between 2011 and 2021. During this period, the institutional osteomyelitis clinical pathway recommended clindamycin for patients with cephalosporin but not penicillin allergy. We compared rates of antibiotics used as definitive therapy between patients with and without documented penicillin allergy. Results Of 365 patients hospitalized with a diagnosis of osteomyelitis, 41 (11.2%) had a documented penicillin allergy. First-generation cephalosporins were administered less frequently to penicillin-allergic patients compared with those without documented penicillin allergy (37% vs. 58%, p=.009), while clindamycin was administered more frequently (22% vs. 10%, p=.02). There was no significant difference in vancomycin use (2% vs. 9%, p=.17). Conclusion Patients with osteomyelitis and a penicillin allergy label were significantly less likely to receive a first-generation cephalosporin and significantly more likely to receive clindamycin. Given higher regional resistance rates and more frequent adverse effects, including Clostridioides difficile infection, of clindamycin relative to first-generation cephalosporins, these data support the need for quality improvement work to increase cephalosporin use in patients with penicillin allergy labels. Disclosures Mari M. Nakamura, MD, MPH, Gilead: Grant/Research Support.

899. Evaluation of a Pharmacist-Led Penicillin Allergy Screening Protocol in a Tertiary Care Hospital

Abstract Background Although penicillin allergy is commonly reported, less than 1% of the population are truly allergic to penicillin. False penicillin allergy labelling may be associated with suboptimal antibiotic selection, greater costs, and higher prevalence of antibiotic-resistant organisms. The purpose of this study was to evaluate outcomes of implementing a pharmacist-led penicillin-allergy screening protocol on the antibiotic prescribing habits and the appropriateness of selecting first line antimicrobial therapy. Methods A retrospective, quasi-experimental study included 97 patients with suspected or confirmed common infections. Data was collected between January 2020 to August 2021 for the pre-protocol implementation group (PPG) and between November 2021 to April 2022 for the post-protocol implementation group (PPI). Adults ( &amp;gt; 18 years) with a documented penicillin allergy were included. Patients with penicillin allergy were identified and interviewed by our Emergency Department (ED) clinical pharmacists using an evidence-based algorithm. Data were analyzed using two-sample Student’s t-test and descriptive statistics. Results Fifty-one patients in PPG and 46 in PPI. In the PPG, 60.8% (31/51) had a history of beta-lactam tolerance and 26% (8/31) tolerated at least a penicillin derivative previously. While, twenty-two patients (47.8%) in the PPI tolerated beta-lactams and 50% (11/22) tolerated at least one penicillin derivative. Thirty-eight patients (82.6%) had a documented infection in the PPI and received an antibiotic. The use of Moxifloxacin was significantly lower in the PPI vs the PPG, 0% (0/38) vs 17.6 (9/51) respectively, (P=0.008). However, the use of ciprofloxacin, vancomycin, and aztreonam was lower in the PPI vs the PPG but was not statistically significant (Table 2). Antibiotic therapy appropriateness was higher in the PPI as compared to the PPG, 86.8% (33/38) vs 49% (25/51) respectively, (P=0.0004). In the PPI, documented penicillin allergies were delabeled in 23.9% (11/46) of patients. Conclusion We observed higher rates of appropriate first line antibiotic therapy selection post-implementation of the pharmacist led penicillin allergy screening protocol. This could be an effective strategy to optimize antimicrobial therapy in the hospital setting. Disclosures All Authors: No reported disclosures.

Drug allergy: A 2022 practice parameter update

Drug allergy: A 2022 practice parameter update

Outpatient penicillin allergy evaluation during pregnancy and associated clinical outcomes

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. This study aimed 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. 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 medical record review. Women referred for penicillin allergy evaluation were compared with 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. 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 of these patients, 167 (95.4%) were considered appropriate for allergy verification testing. Of note, 117 women (70.1%) underwent skin testing with or without graded oral amoxicillin drug challenge, and all but 1 woman (99.1%) were found to be penicillin tolerant. Moreover, 5 additional women were delabeled 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 (adjusted odds ratio, 0.49; 95% confidence interval, 0.27-0.89). Other maternal and neonatal adverse outcomes were less frequent in those referred, but these associations did not reach statistical significance. This study documented 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.

Adherence and outcomes of a surgical prophylaxis guideline promoting cephalosporin use among patients with penicillin allergy

BackgroundThe study purpose was to assess adherence to a local surgical prophylaxis guideline in patients with reported penicillin allergies, which recommends cephalosporins as first-line prophylaxis. MethodsAdult patients with penicillin allergies admitted for a surgical procedure from July 2020 to June 2021 were retrospectively screened, and the first surgery per admission was included. The primary outcome was the proportion of surgeries using β-lactam prophylaxis. Additional outcomes included prophylaxis timing, hypersensitivity reactions, acute kidney injury, infectious complications, duration of stay, and 30-day mortality or readmission. ResultsAmong 597 procedures, 504 patients (84.4%) received a β-lactam for surgical prophylaxis, including 494 (82.3%) who received a cephalosporin. Patients in the non–β-lactam group were more likely to have a type I IgE–mediated penicillin allergy (48.4% vs 31.7%, P = .002); however, the majority with type I reactions still received β-lactams (78.0%), including in the setting of anaphylaxis or angioedema to penicillin (67.7%). Zero allergic reactions to prophylaxis antibiotics were reported in either group, and there were no significant differences in the proportion of patients receiving drugs associated with the management of allergic reactions. Receipt of non–β-lactams was associated with inappropriate prophylaxis timing (9.7% vs 3.2%, P = .005) and postprocedural acute kidney injury (7.5% vs 0.6%, P < .001). All other outcomes were nonsignificant between the groups. ConclusionAmong surgical patients with a documented penicillin allergy, most received cephalosporin prophylaxis as recommended by institutional guidelines, with zero allergic reactions. Receipt of non–β-lactam prophylaxis was associated with worsened outcomes. Cephalosporin prophylaxis should be preferred for surgical patients, including in the setting of true penicillin allergy.

Opportunities for penicillin allergy evaluation in dental clinics.

To evaluate opportunities for assessing penicillin allergies among patients presenting to dental clinics. Retrospective cross-sectional study. VA dental clinics. Adult patients with a documented penicillin allergy who received an antibiotic from a dentist between January 1, 2015, and December 31, 2018, were included. Chart reviews were completed on random samples of 100 patients who received a noncephalosporin antibiotic and 200 patients who received a cephalosporin. Each allergy was categorized by severity. These categories were used to determine patient eligibility for 3 testing groups based on peer-reviewed algorithms: (1) no testing, (2) skin testing, and (3) oral test-dose challenge. Descriptive and bivariate statistics were used to compare facility and patient demographics first between true penicillin allergy, pseudo penicillin allergy, and missing allergy documentation, and between those who received a cephalosporin and those who did not at the dental visit. Overall, 19% lacked documentation of the nature of allergic reaction, 53% were eligible for skin testing, 27% were eligible for an oral test-dose challenge, and 1% were contraindicated from testing. Male patients and African American patients were less likely to receive a cephalosporin. Most penicillin-allergic patients in the VA receiving an antibiotic from a dentist are eligible for penicillin skin testing or an oral penicillin challenge. Further research is needed to understand the role of dentists and dental clinics in assessing penicillin allergies.

142. Impact of an Antimicrobial Stewardship Intervention on Antibiotic Prescribing in Patients with Obstetric Infection and Penicillin Allergy

BackgroundAntibiotics are commonly administered in the peripartum period and most patients with penicillin allergy can tolerate beta lactams, which are preferred for the prophylaxis and treatment of several common obstetric infections. The purpose of this study was to evaluate the impact of a stewardship intervention bundle (including updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of order sets, and a physician champion) on the management of obstetric infections in patients with reported penicillin allergy. MethodsThis was a multicenter, retrospective study of adult patients presenting for labor and delivery who received at least one dose of antibiotics for an infectious indication May 1, 2018 to October 31, 2018 (pre-intervention) and May 1 2020 to October 31, 2020 (post-intervention). The primary outcome was the composite rates of patients with a reported penicillin allergy who received a preferred agent for Group B Streptococcus (GBS) prophylaxis, intraamniotic infection, or cesarean surgical site infection (SSI) prophylaxis. ResultsA total of 192 patients with a documented penicillin allergy were evaluated (96 patients each in pre- and post-intervention groups). Hives were the most commonly reported allergy in both groups (40% vs 39%, P=0.883). Following stewardship interventions, there was a significant increase in the rate of preferred antibiotics prescribed to patients with penicillin allergy (34.3% vs 84.3%, P< 0.001), driven mainly by patients with non-severe allergy (18.4% vs 82.9%, P< 0.001). There were non-statistically significant trends toward lower rates of postpartum endometritis, 30-day readmission, 90-day SSI, and neonatal early onset sepsis. Allergic reactions in the post-intervention group were limited to itching and rash in one patient each; both resolved with medical management. ConclusionA comprehensive antibiotic stewardship intervention increased preferred antibiotic prescribing for treatment and prophylaxis of obstetric infections. Pregnant patients with non-severe penicillin allergies, even those reporting hives, can tolerate beta-lactam antibiotics. The potential positive impact on clinical outcomes warrants additional investigation. Disclosures Neil Seligman, MD, Natera (Consultant)UpToDate (Other Financial or Material Support, Author)