Chronic Spontaneous Urticaria: An Update on the Evaluation and Management.

Chronic spontaneous urticaria (CSU) affects 0.5% to 1% of the general population and is often managed by allergy and immunology specialists. Guidelines have evolved over the past several decades with an emphasis on decreasing extensive screening laboratory testing as they are of low-yield and cost-ineffective. The utility of biomarkers remains under investigation but total immunoglobulin E may be helpful in determining specific endotypes and response to omalizumab. Antihistamines and omalizumab remain the primary therapeutic options for CSU, but an expanding body of evidence supports the use of immunosuppressants and anti-inflammatory medications in refractory cases.

Rechallenges without desensitization following platinum-based chemotherapy reactions.

BACKGROUND: There is increasing interest in non-desensitization protocols as a potential way to reintroduce chemotherapy following hypersensitivity reactions (HSR). OBJECTIVE: To provide insight into the potential utility of non-desensitization reintroduction, particularly at institutions where allergy consultation may not be available. METHODS: For 70 patients with platinum HSR who underwent rechallenge with standard (≤2 hours), extended (1-bag, 1-step, 4-6 hours), or titrated (4-to-5-bag and -step, 6-7.5 hours) infusions between 1/2014 and 7/2019, demographics and clinical characteristics were reviewed and initial and breakthrough reactions (BTR) were graded using Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0). Tolerance (no BTR) and completion (dose completed despite BTR) were compared using Fisher's exact test. RESULTS: Patients (mean [standard deviation] age 57 [13] years, initial HSR grade 2 [1]), were rechallenged with standard (n = 8), extended (n = 23), or titrated (n = 22) infusions after oxaliplatin HSR; and standard (n = 5) or titrated (n = 12) after carboplatin HSR. Tolerance and completion were higher for extended versus (vs) standard (tolerance-87%-vs-8%, p < 0.005; completion-96%-vs-38%, p < 0.005) and titrated versus standard (tolerance-76%-vs-8%, p < 0.005; completion-79%-vs-38%, p < 0.05) infusions. CONCLUSIONS: Extended and titrated infusions may increase reintroduction safety compared to standard infusions. Further investigation into extended infusions may provide a safe alternative to standard infusions in patients who may not have access to desensitization at their institution.

What can inherited immunodeficiencies reveal about pyoderma gangrenosum?

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic dermatosis that is occasionally associated with primary immunodeficiency. Though contributions from dysregulation of the innate immune system, neutrophil dysfunction and genetic predisposition have been postulated, the precise pathogenesis of PG has not yet been elucidated. This article reviews reported cases of coexisting PG and primary immunodeficiency in order to gain insight into the complex pathophysiology of PG. Our findings suggest that variations in genes such as RAG1, ITGB2, IRF2BP2 and NFκB1 might play a role in genetically predisposing patients to develop PG. These studies support the feasibility of the role of somatic gene variation in the pathogenesis of PG which warrants further exploration to guide targeted therapeutics.

Impact of an Inpatient Allergy Guideline on ß-Lactam and Alternative Antibiotic Use.

BACKGROUND: A guideline identifying when inpatients with penicillin or cephalosporin antibiotic allergy labels (PCAAL) can receive ß-lactam antibiotics increased ß-lactam receipt at a large northeastern US health care system. OBJECTIVE: To report outcomes of implementing a similar guideline and electronic order set (OS) at an independent academic health care system. METHODS: Penicillin/cephalosporin receipt (percentage of inpatients receiving full doses) and alternative antibiotic use (days of therapy per 1000 patient-days [DOT/1000PD]) were compared over 3 periods before (February 1, 2017, to January 31, 2018) and after guideline implementation (February 1, 2018, to January 31, 2019), and after OS implementation (February 1, 2019, to January 31, 2020) among inpatients with PCAAL admitted on medical services with access to guideline/OS and education (Medical-PCAAL, n = 8721), surgical services with access to guideline/OS without education (Surgical-PCAAL, n = 5069), and obstetrics/gynecology services without interventions (Ob/Gyn-PCAAL, n = 798) and inpatients without PCAAL admitted on the same services (Medical-No-PCAAL, n = 50,840; Surgical-No-PCAAL, n = 29,845; Ob/Gyn-No-PCAAL, n = 6109). χ2 tests were used to compare categorical variables, and analysis of variance was used to compare continuous and interrupted time series analyses (ITSA) to investigate the guideline/OS implementation effect on penicillin/cephalosporin receipt. RESULTS: In the Medical-PCAAL group, penicillin/cephalosporin receipt increased (58%-68%, P < .001), specifically for cefazolin (8%-11%, P = .02) and third- to fifth-generation cephalosporins (43%-48%, P = .04), and aztreonam use decreased (12 DOT/1000PD, P = .03). In the Medical-No-PCAAL group, penicillin/cephalosporin receipt increased (88%-90%, P = .004), specifically for penicillin (40%-44%, P < .001), without changes in aztreonam use. Significant changes were not observed in these outcomes on surgical or obstetrics/gynecology services. Per ITSA, guideline/OS implementation was associated with increased penicillin/cephalosporin receipt in the Medical-PCAAL group only. CONCLUSION: Guideline and OS implementation was associated with improved antibiotic stewardship on inpatient services that also received allergy education.

Efficacy and safety of an e-consult program for COVID-19 vaccine allergy concerns.

Background: Although severe allergic reactions to coronavirus disease 2019 (COVID-19) vaccines are rare, fear of allergic reactions remains a major source of vaccine hesitancy. For concerned patients and providers alike, allergist consultation is recommended for further guidance on the risk of vaccination. The electronic consultation (e-consult) medium has the potential to make this guidance more widely accessible, thereby supporting vaccination efforts. Objective: To determine the safety and efficacy of an e-consult program for COVID-19 vaccine allergy concerns. Methods: We performed a retrospective analysis of a single-center COVID-19 vaccine allergy e-consult program. Data on demographics, allergy history, and outcomes after recommendations were gathered via review of the electronic medical record (EMR). Patients without EMR data available following the e-consult were called to inquire about vaccination status. Results: Our study included 64 patients, most of whom (51.6% [33/64]) had e-consults placed for second-dose concerns. E-consults were completed within 2 days for all patients. The most common recommendation was that patients receive any COVID-19 vaccination available (62.5%, [40/64]). Forty-one patients (64.1%) were vaccinated after receiving recommendations from an allergist, 11 of whom (26.8%) reported a vaccine reaction. Most of these reactions were nonallergic (9/11 [81.2%]). No anaphylactic events were reported. Conclusion: Results of our study suggest that e-consults were a safe and effective method of providing guidance with regard to COVID-19 vaccine risk in patients with concerns about allergic reactions. The efficiency of this medium, highlighted by the 2-day turnaround time in our study, has the potential to expand access to vaccine risk evaluations by board-certified allergist/immunologists.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations.

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with ß-lactam antibiotic allergies and high-risk populations likely to need ß-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and ß-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. ß-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line ß-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

Enabling antibiotic allergy evaluations and reintroduction of first-line antibiotics for patients with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) often have a history of antibiotic adverse drug reactions (ADRs) that pose a barrier to receiving recommended first-line treatment. Targeted antibiotic allergy evaluations are increasingly recognized as an important strategy for optimization of antimicrobial stewardship. OBJECTIVE: To improve first-line antibiotic use in patients with CF with antibiotic ADRs by streamlining access to antibiotic allergy evaluations and standardizing documentation of plans for antibiotic reintroduction. METHODS: We incorporated allergy evaluations into a multidisciplinary CF clinic and used telemedicine when allergy evaluations could not be performed during CF clinic. Standard documentation of antibiotic allergy plans was used to enable safe reintroduction of first-line antibiotics by CF providers. RESULTS: Strategies used in this study allowed 81.3% (26 of 32) of patients with CF to receive allergy evaluations and antibiotic allergy plans for prioritized antibiotics (penicillin, cephalosporin, sulfonamide), with removal of 41.0% (16 of 39) of prioritized antibiotic ADRs. Only 5.1% (2 of 39) of prioritized antibiotic ADRs evaluated required strict avoidance after evaluation. There were 9 patients who received at least 1 prioritized antibiotic, with 66.6% (6 of 9) of these patients given the antibiotic after only 1 allergy evaluation visit. Furthermore, these strategies allowed allergy evaluations of 23 nonprioritized antibiotics to occur, with removal of the ADR in 39.1% (9 of 23) and use of 77.8% (7 of 9) of nonprioritized antibiotics after removal. CONCLUSION: Incorporating allergy evaluations into a multidisciplinary CF clinic can liberalize first-line antibiotic use in patients with CF. Standard documentation of antibiotic allergy plans allowed antibiotic reintroduction to occur even before complete removal of documented antibiotic ADRs.