Introduction of a penicillin allergy de-labelling program with direct oral challenge and its effects on utilization of beta-lactam antimicrobials: a multicenter retrospective parallel cohort study.

BACKGROUND: Self-reported penicillin allergy labels are common and often inaccurate after assessment. These labels can lead to reduced use of first-line beta-lactam antibiotics and worse outcomes. We measured the impact of a previously performed inpatient proactive systematic penicillin allergy de-labelling program on subsequent antibiotic use. This prior program included assessment, risk-stratification, and low risk direct oral amoxicillin challenge. METHODS: We performed a retrospective comparison of parallel cohorts from two separate tertiary care hospital campuses in Ottawa, Canada across two penicillin de-labelling intervention periods across April 15th to April 30th, 2021, and February 15th to March 8th, 2022. Outcomes, including penicillin allergy labelling and antibiotic use, were collected for the index admission and the subsequent 6-month period. Descriptive statistics and multivariate regression analyses were performed. RESULTS: A total of 368 patients with penicillin allergy label were included across two campuses and study periods. 24 (13.8%) patients in the intervention groups had sustained penicillin allergy label removal at 30 days from admission vs. 3 (1.5%) in the non-intervention group (p < 0.001). In the 6-months following admission, beta-lactams were prescribed more frequently in the intervention groups vs. the non-intervention groups for all patients (28 [16.1%] vs.15 [7.7%], p = 0.04) and were prescribed more frequently amongst those who received at least one antibiotic (28/46 [60.9%] vs.15/40 [37.5%], p = 0.097). In a multivariate regression analysis, the intervention groups were found to be associated with an increased odds of beta-lactam prescribing in all patients (OR 2.49, 95%CI 1.29-5.02) and in those prescribed at least one antibiotic (OR 2.44, 95%CI 1.00-6.15). No drug-related adverse events were reported. CONCLUSIONS: Proactive penicillin allergy de-labelling for inpatients was associated with a reduction in penicillin allergy labels and increased utilization of beta-lactams in the subsequent 6-months.

Resource utilization and cost assessment of a proactive penicillin allergy de-labeling program for low-risk inpatients.

BACKGROUND: Resource utilization and costs can impede proactive assessment and de-labeling of penicillin allergy among inpatients. METHODS: Our pilot intervention was a proactive penicillin allergy de-labeling program for new inpatients with penicillin allergy. Patients deemed appropriate for a challenge with a low-risk penicillin allergy history were administered 250 mg amoxicillin and monitored for 1 h. We performed an explorative economic evaluation using various healthcare professional wages. RESULTS: Over two separate 2-week periods between April 2021 and March 2022, we screened 126 new inpatients with a penicillin allergy. After exclusions, 55 were appropriate for formal assessment. 19 completed the oral challenge, and 12 were directly de-labeled, resulting in a number needed to screen of 4 and a number needed to assess of 1.8 to effectively de-label one patient. The assessor's median time in the hospital per day de-labeling was 4h08 with a range of (0h05, 6h45). A single-site annual implementation would result in 715 penicillin allergy assessments with 403 patients de-labeled assuming 20,234 annual weekday admissions and an 8.9% penicillin allergy rate. Depending on the assessor used, the annual cost of administration would be between $21,476 ($53.29 per effectively de-labeled patient) for a pharmacy technician and $61,121 ($151.67 per effectively de-labeled patient) for a Nurse Practitioner or Physician Assistant. CONCLUSION: A proactive approach, including a direct oral challenge for low-risk in-patients with penicillin allergy, appears safe and feasible. Similar programs could be implemented at other institutions across Canada to increase access to allergy assessment.

Delayed hypersensitivity reaction to cosmetic filler following two COVID-19 vaccinations and infection.

BACKGROUND: With ongoing COVID-19 vaccination schedules and the popularity of cosmetic fillers, it is important to examine and record associated adverse reactions to a more general audience of health care professionals. Case reports exist in subspecialty journals outlining reactions after SARS-CoV-2 infection and vaccination. This is one of the first cases published in Canada, and it highlights priorities and challenges faced by physicians in assessing and managing patients presenting with adverse reactions post vaccination. CASE PRESENTATION: We present a case of a 43 -year-old women with delayed type 4 hypersensitivity reaction to hyaluronic acid cosmetic filler triggered by COVID-19 mRNA vaccination. We outline the clinical presentation, diagnosis, complications, and treatment of a late inflammatory reaction to hyaluronic acid filler and highlight the treatment priorities for clinicians faced with similar presentations. CONCLUSION: The differential diagnosis of delayed onset nodules formation post filler injection is broad and includes redistribution of fillers, inflammatory reaction to biofilm, and delayed hypersensitivity reaction. As result, in order to make the right diagnosis, administer the appropriate treatment and achieve great cosmetic results, we highly recommend seeking expert opinion from dermatologist, plastic surgeon and allergist immunologist in a timely manner.

Association of antibiotic allergy labels with hospital length of stay.

BACKGROUND: Many antibiotic allergy labels (AAL) are invalid. Excluding true allergy in people with AAL ("delabeling") could improve health outcomes and decrease costs. Several studies with limited covariate adjustment have associated AAL with a prolonged hospital length of stay (LOS). OBJECTIVE: This study determined whether AAL's association with LOS persisted after extensive adjustment for potential confounders and covariates. METHODS: All nonpsychiatric admissions to a tertiary care teaching hospital from 2012 to 2015 were included. Generalized estimating equation methods were used to model the daily discharge likelihood as a function of AAL and other important factors (death risk score, daily discharge score, daily severity of illness score, antibiotic use, hospital day and location, weekend-holiday status, and service). RESULTS: A total of 111,611 admissions (76,460 patients) were studied, in which 16,489 (14.8%) had recorded AAL. Patients with an AAL had a notably greater disease burden: they were older and had more comorbidities, greater health system utilization, and higher death risk. In the univariate analysis, AAL was associated with a significantly decreased daily discharge likelihood (odds ratio [OR], 0.93; [95% confidence interval, 0.90-0.95]). After adjustment for potential confounders and covariates, AAL was not associated with daily discharge likelihood (adjusted OR [aOR] without antibiotics: 1.00 [0.98-1.03]; aOR with antibiotics: 1.02 [0.99-1.04]). Similar results were also seen with penicillin AAL (aOR without antibiotics: 0.99 [0.95-1.02]; aOR with antibiotics: 1.00 [0.96-1.03]). CONCLUSION: Antibiotic allergy label was strongly associated with a greater disease burden. After adjusting for important covariates, our analysis found no significant association between AAL and hospital LOS.