Detection of Newly Secreted Antibodies Predicts Nonrecurrence in Primary Clostridioides difficile Infection.

Within 8 weeks of primary Clostridioides difficile infection (CDI), as many as 30% of patients develop recurrent disease with the associated risks of multiple relapses, morbidity, and economic burden. There are no clear clinical correlates or validated biomarkers that can predict recurrence during primary infection. This study demonstrated the potential of a simple test for identifying hospitalized CDI patients at low risk for disease recurrence. Forty-six hospitalized CDI patients were enrolled at Emory University Hospitals. Samples of serum and a novel matrix from circulating plasmablasts called "medium-enriched for newly synthesized antibodies" (MENSA) were collected during weeks 1, 2, and 4. Antibodies specific for 10 C. difficile antigens were measured in each sample. Among the 46 C. difficile-infected patients, 9 (19.5%) experienced recurrence within 8 weeks of primary infection. Among the 37 nonrecurrent patients, 23 (62%; 23/37) had anti-C. difficile MENSA antibodies specific for any of the three toxin antigens: TcdB-CROP, TcdBvir-CROP, and/or CDTb. Positive MENSA responses occurred early (within the first 12 days post-symptom onset), including six patients who never seroconverted. A similar trend was observed in serum responses, but they peaked later and identified fewer patients (51%; 19/37). In contrast, none (0%; 0/9) of the patients who subsequently recurred after hospitalization produced antibodies specific for any of the three C. difficile toxin antigens. Thus, patients with a negative early MENSA response against all three C. difficile toxin antigens had a 19-fold greater relative risk of recurrence. MENSA and serum levels of immunoglobulin A (IgA) and/or IgG antibodies for three C. difficile toxins have prognostic potential. These immunoassays measure nascent immune responses that reduce the likelihood of recurrence thereby providing a biomarker of protection from recurrent CDI. Patients who are positive by this immunoassay are unlikely to suffer a recurrence. Early identification of patients at risk for recurrence by negative MENSA creates opportunities for targeted prophylactic strategies that can reduce the incidence, cost, and morbidity due to recurrent CDI.

Asthma diagnosis using patient-reported outcome measures and objective diagnostic tests: now and into the future.

PURPOSE OF REVIEW: The global prevalence of asthma continues to increase; however, asthma remains under-diagnosed and under-treated. This results in a significant burden on the healthcare system and preventable patient morbidity and mortality. Over-diagnosis of asthma based on clinical history alone also complicates patient management. This heightens the importance of a prompt and accurate asthma diagnosis. Therefore, a review of the literature was performed regarding both objective diagnostic testing for asthma and using patient-reported outcome measures. RECENT FINDINGS: The cornerstone of asthma diagnosis remains spirometry with testing for bronchodilator reversibility testing for pediatric and adult populations. This test may need to be repeated at multiple time points due to its low sensitivity. Peak flow measurement, fractional exhaled nitric oxide testing, and allergy testing are useful adjuncts to the diagnosis and phenotyping of asthma. Bronchoprovocation testing is reserved for people with high clinical suspicion for asthma, but negative spirometry. Novel noninvasive testing modalities may play a diagnostic role in the future. The advent of remote digital health monitoring technology has resulted in revisiting patient-reported outcome measures for the diagnosis and monitoring of asthma. SUMMARY: Overall, improved diagnostic tools for asthma are crucial for earlier recognition and treatment of the disease and improved patient care outcomes worldwide.

Treatment strategies for postviral olfactory dysfunction: A systematic review.

Background: The coronavirus disease 2019 (COVID-19) pandemic has been associated with a dramatic increase in postviral olfactory dysfunction (PVOD) among patients who are infected. A contemporary evidence-based review of current treatment options for PVOD is both timely and relevant to improve patient care. Objective: This review seeks to impact patient care by qualitatively reviewing available evidence in support of medical and procedural treatment options for PVOD. Systematic evaluation of data quality and of the level of evidence was completed to generate current treatment recommendations. Methods: A systematic review was conducted to identify primary studies that evaluated treatment outcomes for PVOD. A number of medical literature data bases were queried from January 1998 to May 2020, with completion of subsequent reference searches of retrieved articles to identify all relevant studies. Validated tools for the assessment of bias among both interventional and observational studies were used to complete quality assessment. The summary level of evidence and associated outcomes were used to generate treatment recommendations. Results: Twenty-two publications were identified for qualitative review. Outcomes of alpha-lipoic acid, intranasal and systemic corticosteroids, minocycline, zinc sulfate, vitamin A, sodium citrate, caroverine, intranasal insulin, theophylline, and Gingko biloba are reported. In addition, outcomes of traditional Chinese acupuncture and olfactory training are reviewed. Conclusion: Several medical and procedural treatments may expedite the return of olfactory function after PVOD. Current evidence supports olfactory training as a first-line intervention. Additional study is required to define specific treatment recommendations and expected outcomes for PVOD in the setting of COVID-19.

Immediate Reactions After the First Dose of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Messenger RNA Vaccines Do Not Preclude Second-Dose Administration.

Addressing coronavirus disease 2019 (COVID-19) vaccine hesitancy and minimizing potential vaccine contraindications are critical to combatting the pandemic. We describe a practical approach to immediate adverse events after the first dose of messenger RNA vaccines for severe acute respiratory syndrome coronavirus 2, focusing on diagnosis and management of allergic reactions.

The spectrum of allergic ocular diseases.

OBJECTIVE: The purpose of this article is to review the pathophysiologic mechanisms, differential diagnosis, evaluation, and treatment of the various manifestations of ocular allergy, with an especial focus on immunoglobulin E (IgE)-mediated disease. DATA SOURCES: A PubMed search was performed to include articles, using the search terms ocular allergy and allergic conjunctivitis. STUDY SELECTIONS: Recent and relevant human studies in the English language pertaining to our topic of study were selected. Animal studies pertaining to pathophysiology of ocular allergy were also reviewed. We focused on clinical trials, practice guidelines, reviews, and systematic reviews. In addition, case reports were reviewed if they described rare clinical presentations, disease mechanisms, or novel therapies. RESULTS: Ocular allergy encompasses both IgE- and non-IgE-mediated disease, and the clinical severity may range from mild to sight-threatening inflammation. A comprehensive treatment regimen including education, lifestyle measures, topical therapies, and even systemic interventions may be necessary for the effective management of ocular allergies, tailored according to symptom severity. CONCLUSION: Ocular allergy is frequently encountered by allergists and eye-care specialists, and despite progressively increasing incidence, it often remains underdiagnosed and, hence, untreated.

Approach to Perioperative Anaphylaxis in 2020: Updates in Diagnosis and Management.

PURPOSE OF REVIEW: The goal of the paper is to review the epidemiology, pathogenesis, diagnosis, and manifestations of perioperative anaphylaxis (POA). We seek to review the most common culprits of POA and different diagnostic modalities for evaluation. RECENT FINDINGS: Specific IgE testing has a limited role in POA evaluation due to lack of widespread availability and low sensitivity. Basophil activation testing is complementary to skin tests and can assist NMBA sensitivity diagnosis in complex cases. In the past years, there has been an exponential increase in suspected teicoplanin allergic reactions in the European Union. Chlorhexidine is also being increasingly implicated as a culprit in POA. Multiple classes of perioperative medications cause POA. Diagnostic modalities available include skin testing with nonirritating concentrations, basophil activation tests, specific IgE, and drug provocation testing. An accurate record and critical analysis of perioperative events is more important than isolated test results. Future studies evaluating the pathophysiology of these reactions and other therapeutic strategies, such as targeting the MRGPRX2 receptor, are needed.

Absence of Iodinated Contrast Hypersensitivity and Characterization of Gadolinium Utilization in an Interventional Pain Population.

BACKGROUND: Iodinated contrast media (ICM) allergy labels pose a unique clinical problem for the interventional pain physician due to the drawbacks of gadolinium for enhancement during pain procedures, as well as the reluctance to add to the cumulative steroid burden with steroid premedication. However, the risks of ICM hypersensitivity specific to this setting have not been previously described. METHODS: We aimed to describe the incidence of ICM-induced hypersensitivity during the performance of epidural injections in a large healthcare system. We also sought to characterize preexisting ICM allergy labels and how these affected consequent gadolinium utilizations in this population. RESULTS: 6,471 epidural pain procedures requiring contrast enhancement were performed during the 18-month study period. There were no reported contrast-induced hypersensitivity reactions in this time. 108 patients (1.6%) had a preexisting ICM allergy; a shellfish/seafood allergy was recorded in 118 patients (1.82%), and 51 charts (0.78%) were labeled with "iodine" allergy. 183 individuals received gadolinium for enhancement during epidural steroid injections. 96.7% of gadolinium utilization occurred in the context of preexisting allergy labels in the electronic medical record. Of note, 20 patients (18.5%) with ICM allergy labels also received iodinated contrast, and this was uneventful in all cases. CONCLUSION: Our results suggest that ICM-associated hypersensitivity is very rare during epidural procedures and the incidence is significantly lower than expected based on reaction rates during intravascular administration. This may be related to both dose as well as route of administration. The establishment of a protocol for safe workup of ICM allergy labels would be useful in optimizing pain procedures.

Clinical use of biologics for asthma treatment by allergy specialists: A questionnaire survey.

BACKGROUND: Asthma is a heterogeneous disease with emerging phenotypes and endotypes. At present, 5 distinct biologics are Food and Drug Administration-approved as an add-on therapy for difficult-to-control type 2-high asthma. Because allergy specialists manage a spectrum of diseases for which biologics may be appropriate, it is important to understand their prescribing patterns. OBJECTIVE: To elucidate the allergist's use of biologics in the treatment of asthma, including barriers, preferences, indications for prescribing, measures to determine effectiveness, and cost-effectiveness. METHODS: A survey was performed among allergists using a semistructured 10-item self-administered web-based questionnaire and the responses were analyzed using one-way frequencies and multiple logistic regression. RESULTS: The response rate was approximately 9%. Omalizumab was the most prescribed biologic for asthma (98%), and "uncontrolled asthma despite adherence to controller medication" was the most common reason. The common selection criteria among the biologics included elevated peripheral eosinophil count, asthma with nasal polyps, and asthma type (type 1; type 2; nonallergic). A decreased exacerbation frequency was the best standard to determine the efficacy among biologics. Benralizumab was considered the most cost-effective. CONCLUSION: This study represents one of the largest surveys among allergy specialists regarding the real-world use of asthma biologics. It seems that there has been reasonably good dissemination and application of current guidelines among allergists based on prescribing patterns. However, their responses reflect the need for the continued modification of asthma guidelines that incorporate novel biologics and other pathway-specific agents into step therapy. As clinical phenotypes and predictive biomarkers develop, allergy specialists will be better prepared to practice precision medicine that optimizes the use of asthma biologics.

Neuropathic Pain and Itch Mechanisms Underlying Allergic Conjunctivitis.

OBJECTIVE: Among the constellation of symptoms that characterizes allergic conjunctivitis, many (eg, burning and stinging) can be attributed to chronic neuropathic pain. Cumulative data support that these hallmark symptoms might be linked to the effects of allergen-induced neuromodulation. This review investigates the key characteristics of neuropathic itch and pain in allergic conjunctivitis and their underlying pathogenic mechanisms. METHODS: A literature review was conducted using a PubMed search focusing on allergic conjunctivitis, neurogenic inflammation, neuropathic itch, and neuropathic pain. Articles were reviewed, and those discussing clinical course, pathophysiology, and neuronal regulation of chronic neuropathic symptoms as related to allergic disease were summarized. RESULTS: Recent evidence suggests that some symptoms of allergic conjunctivitis may be better represented as a chronic neuropathic disorder. We found that neurogenic mechanisms may have a significant role in chronic ocular surface inflammation from allergic inflammation. Manifestations may be associated with repeated ocular sensory nerve injury leading to an acute-to-chronic transition, which is in turn associated with neuropathologic changes (peripheral and central sensitization), neuronal dysfunction, and spontaneous ocular pain. CONCLUSION: Current goals in the management of allergic conjunctivitis aim to minimize the inflammatory cascade associated with the allergic response in the initial stages of the pathogenic mechanism. Based on the mechanistic data reviewed herein, the recognition that neuronal inflammation explains many of the symptoms in allergic conjunctivitis opens new frontiers for drug discovery.

Direct oral amoxicillin challenge without preliminary skin testing in adult patients with allergy and at low risk with reported penicillin allergy.

Introduction: Ten percent of hospitalized patients report penicillin allergy; however, recent studies indicate that ∼98% of these patients are not acutely hypersensitive. Unconfirmed penicillin allergy poses public health risks, and an evaluation of penicillin allergy labels is recommended to improve antibiotic stewardship. Although the most widely accepted protocol is penicillin skin testing, followed by oral amoxicillin challenge, time constraints and resources may preclude this. Recent literature supports the safety and efficacy of direct oral amoxicillin challenge in individuals at low risk. Methods: We retrospectively evaluated direct oral challenge acceptance and outcomes in eligible adult outpatients with allergy and with a penicillin allergy label over a 6-month period. Direct oral amoxicillin challenge was recommended in patients with a history of benign rash, benign somatic symptoms, or unknown history associated with the last penicillin exposure >12 months ago. Those with severe reactions or reactions within 12 months of evaluation were not challenged. The patients were monitored for 60 minutes after challenge and were discharged with instructions to call in the event of a delayed reaction. Results: There were 50 of 355 adults (14%) with a penicillin allergy label seen by a single allergist; of these patients, 38 (76%) met our criteria for a direct oral challenge. The index penicillin associated reactions were mostly remote, and 44 subjects (88%) reported reactions >10 years earlier. Four patients (8%) were de-labeled based on history alone. Twenty subjects (40%) consented to challenge in the clinic, and none developed immediate, or to our knowledge, delayed hypersensitivity reactions. Three of 20 patients (15%) developed self-limited subjective symptoms that were not deemed to constitute true immunoglobulin E mediated hypersensitivity. A total of 24 patients (48%) had the penicillin allergy label removed from their medical record. Conclusion: This study added to the accumulating body of evidence that supports the safety and efficacy of direct provocative challenge without preliminary skin testing to exclude penicillin allergy in individuals at low risk. Larger prospective studies are necessary to confirm these observations.

Management of Penicillin Allergy in the Perioperative Setting.

The selection of perioperative antibiotic prophylaxis is challenging in patients with a history of penicillin allergy; as such, we present a literature review exploring current best practices and the associated supporting evidence, as well as areas for future research. Guidelines recommend the use of alternative agents in patients with an IgE-mediated hypersensitivity reaction, but those alternative agents are associated with worse outcomes, including an increased risk of surgical site infection, and higher cost. More recent data suggest that the risk of cross-reactivity between penicillins and cephalosporins, particularly cefazolin, is extremely low, and that cefazolin can be used safely in most penicillin-allergic patients. Studies have therefore explored how best to implement first-line cefazolin use in patients with a penicillin allergy label. A variety of interventions, including preoperative allergy de-labeling with incorporation of penicillin skin testing, use of patient risk-stratification questionnaires, and utilization of clinician algorithms to guide antibiotic selection intraoperatively, have all been shown to significantly increase cefazolin utilization without a corresponding increase in adverse events. Further studies are needed to clarify the most effective interventions and implementation strategies, as well as to evaluate whether patients with severe delayed hypersensitivity reactions to penicillin should continue to be excluded from receipt of other beta-lactams.

Disease burden and predictors associated with non-response to antihistamine-based therapy in chronic spontaneous urticaria.

Background: H1-antihistamines (H1AH) are the first-line treatment for chronic spontaneous urticaria (CSU), but 50% of patients have inadequate disease control at standard doses. Objective: To assess the comorbidity burden and healthcare resource utilization (HRU) associated with non-response to H1AH-based treatments; to identify predictors of non-response. Methods: Optum® de-identified Electronic Health Record dataset (2007-2020) was used to identify adult patients with CSU who initiated a H1AH, alone or in combination with other oral non-biologics (index treatment). Based on twelve-month treatment patterns observed after index treatment initiation, patients were categorized as responders (continued index treatment or had only 1 next H1AH treatment without corticosteroids) or non-responders (continued corticosteroids or had 2 or more treatment switches). Patient characteristics and HRU were assessed in the 12 months before (baseline) and ≥12 months after (follow-up) index treatment initiation. Baseline predictors associated with non-response were identified using machine learning. Results: There were 17 062 patients who met inclusion criteria, and 14824 (86.9%) were classified as non-responders. A higher proportion of non-responders had records of CSU-related symptoms, comorbidities, polypharmacy, and certain laboratory tests than responders at baseline. A higher proportion of non-responders than responders visited an allergist or dermatologist during follow-up (59.5% vs 53.0%). Non-responders had a larger increase in hospitalizations (15.7% vs -2.4%) than responders during follow-up vs baseline. Predictors of non-response included index and baseline treatment classes, types of specialists seen, chronic pulmonary disease, depression, and female sex. Conclusion: A large proportion of CSU patients treated with H1AH-based therapies had uncontrolled disease, contributing to increased HRU and patient burden. Non-responders had more comorbidities and HRU at baseline and follow-up, with steep increases in follow-up hospitalizations relative to baseline, highlighting an urgent need for early disease control.