Anaphylaxis: A 2023 practice parameter update.

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

Pharmacokinetics/pharmacodynamics of epinephrine after single and repeat administration of neffy, EpiPen, and manual intramuscular injection.

BACKGROUND: Epinephrine is the first-line treatment for severe allergic reactions, and rapid treatment is associated with lower rates of hospitalization and death. Current treatment options (epinephrine auto-injectors and manual intramuscular injection) are considered cumbersome, and most patients/caregivers fail to use them, even during severe reactions. An intranasal epinephrine delivery device, neffy, has been designed to provide an additional option for patients/caregivers. OBJECTIVE: We sought to assess the comparative pharmacokinetics and pharmacodynamics of neffy 2.0 mg, EpiPen 0.3 mg, and manual intramuscular injection 0.3 mg. METHODS: This was a phase 1, randomized, 6-treatment, 6-period, 2-part crossover study in 59 healthy subjects. Pharmacokinetic and pharmacodynamic parameters following single and repeat doses of epinephrine were assessed before dosing and at various postdose intervals. RESULTS: The pharmacokinetic profile of neffy was bracketed by approved injection products, with a mean peak plasma level of 481 pg/mL, which fell between EpiPen (753 pg/mL) and epinephrine manual intramuscular injection (339 pg/mL). When dosed both once and twice, neffy resulted in more pronounced increases in pharmacodynamic parameters relative to EpiPen or manual injection. CONCLUSIONS: neffy's pharmacokinetic profile was bracketed by approved injection products, with pharmacodynamic responses that were comparable to or better than approved injection products. neffy is expected to be a safe and effective option, particularly for patients/caregivers who are reluctant to carry and use injection devices.

The Joint Task Force on Practice Parameters GRADE guidelines for the medical management of chronic rhinosinusitis with nasal polyposis.

These evidence-based guidelines support patients, clinicians, and other stakeholders in decisions about the use of intranasal corticosteroids (INCS), biologics, and aspirin therapy after desensitization (ATAD) for the management of chronic rhinosinusitis with nasal polyposis (CRSwNP). It is important to note that the current evidence on surgery for CRSwNP was not assessed for this guideline nor were management options other than INCS, biologics, and ATAD. The Allergy-Immunology Joint Task Force on Practice Parameters formed a multidisciplinary guideline panel balanced to include the views of multiple stakeholders and to minimize potential biases. Systematic reviews for each management option informed the guideline. The guideline panel used the Grading of Recommendations Assessment, Development and Evaluation approach to inform and develop recommendations. The guideline panel reached consensus on the following statements: (1) In people with CRSwNP, the guideline panel suggests INCS rather than no INCS (conditional recommendation, low certainty of evidence). (2) In people with CRSwNP, the guideline panel suggests biologics rather than no biologics (conditional recommendation, moderate certainty of evidence). (3) In people with aspirin (nonsteroidal anti-inflammatory drug)-exacerbated respiratory disease, the guideline panel suggests ATAD rather than no ATAD (conditional recommendation, moderate certainty of evidence). The conditions for each recommendation are discussed in the guideline.

Updated guidance regarding the risk of allergic reactions to COVID-19 vaccines and recommended evaluation and management: A GRADE assessment and international consensus approach.

This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against >15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history.

Evidence-based use of antihistamines for treatment of allergic conditions.

Available since the 1940s, H1 antihistamines are mainstay treatments for allergic conditions such as allergic rhinitis and urticaria. They function as inverse agonists that bind to the H1 receptor to inhibit histamine-induced inflammation. The older, first-generation drugs are no longer recommended for patient use because of their well-documented negative adverse effect profile. Evidence has been accumulating to support a newer generation of H1 antihistamines in oral and intranasal formulations, including in combination with intranasal corticosteroids. The literature is replete with large meta-analyses and systematic reviews establishing the safety and efficacy of second-generation H1 antihistamines in adult and pediatric allergic rhinitis populations, including combination nasal spray agents (eg, MP29-02 or MP-AzeFlu). Although intraclass differences do exist, patient preference, access, and costs should be the priority. Robust data on the regular, not as needed use of H1 antihistamines for urticaria have been published, including in the management of children and pregnant or lactating women. In addition, H1 antihistamines can be used in other related allergic conditions, such as the secondary symptoms of anaphylaxis, to provide patients with greater comfort, including in allergic asthma, depending on the individual.

Trends in the proportion of women speakers at North American Allergy and Immunology conferences, 2008 to 2020.

BACKGROUND: Women in medicine continue to be underrepresented at medical conferences. Previous studies have evaluated the proportion of invited female speakers across multiple specialties and evaluated factors that may have led to this disparity. The field of Allergy and Immunology has often been excluded and analyses have not illustrated how the trends have changed over the past decade. OBJECTIVE: To evaluate the distribution of invited speakers by gender over time at the 3 largest North American Allergy and Immunology conferences. METHODS: This retrospective longitudinal analysis used conference programs from 2008 to 2020 from the American Academy of Allergy, Asthma, and Immunology (AAAAI), the American College of Allergy, Asthma, and Immunology (ACAAI), and the Canadian Society of Allergy and Clinical Immunology (CSACI). The gender (binary definition, man or woman, based on names, photos, pronouns, from conference programs and institutional profiles) of invited speakers was analyzed as the primary outcome, and planning committee members, and multispeaker sessions as secondary outcomes. These data were compared with publicly available data on the composition of the specialty by gender in the United States and Canada. RESULTS: Women speakers at AAAAI, ACAAI, and CSACI conferences have historically been lower than male speakers and underrepresented compared with specialty composition. However, there has been a significant increase in the proportion of women speakers over time for all 3 conferences individually (AAAAI: 23.7% in 2008, 41.1% by 2020; ACAAI: 16.7% in 2008, 37.3% by 2020; CSACI: 19.4% in 2008, 54.8% by 2020; P < .001 for each) and combined (21.3% in 2008, 40.7% by 2020, P < .001). This trend coincides with a significant increase in women on the planning committee (all conferences: 20% in 2008, 50.6% by 2020; P < .001). There is also a decreasing trend over time for men-only multispeaker sessions. CONCLUSION: This study sheds light on the trends of women speaker representation at Allergy and Immunology conferences and provides clarity on future needs to reach equal representation in this field.

Epinephrine autoinjectors: individualizing device and dosage to optimize anaphylaxis management in the community setting.

Background: Anaphylaxis is the most severe manifestation of a systemic allergic reaction, and, in the community setting, the immediate administration of an epinephrine autoinjector (EAI) can be life-saving. Physicians are tasked with selecting the most appropriate EAI for each individual and counseling patients and/or their caregivers to maximize the likelihood of successful deployment of the EAI. Objective: To offer an evidence-based expert clinical perspective on how physicians might best tailor EAI selection to their patients with anaphylaxis. Methods: A group of eight adult and pediatric allergists with expertise in anaphylaxis management reviewed and assessed the published data and guidelines on anaphylaxis management and EAI device selection. Results: Personalized EAI selection is influenced by intrinsic individual factors, extrinsic factors such as the properties of the individual EAI (e.g., dose, needle length, overall design) as well as cost and coverage. The number and the variety of EAIs available have expanded in most jurisdictions in recent years, which provide a greater diversity of options to meet the characteristics and needs of patients with anaphylaxis. Conclusion: There currently are no EAIs with customizable dose and needle length. Although precise personalization of each patient's EAI remains an optimistic future aspiration, careful consideration of all variables when prescribing EAIs can support optimal management of anaphylaxis.

Topical corticosteroids for chronic rhinosinusitis with nasal polyposis: GRADE systematic review and network meta-analysis.

BACKGROUND: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is associated with a significant disease burden. The optimal use of and administration route for intranasal corticosteroids (INCS) when managing CRSwNP are unclear. OBJECTIVE: We systematically synthesized the evidence addressing INCS for CRSwNP. METHODS: We searched studies archived in Medline, Embase, and Central from database inception until September 1, 2021, for randomized controlled trials comparing INCS using any delivery method to placebo or other INCS administration types. Paired reviewers screened records, abstracted data, and rated risk of bias (CLARITY revision of Cochrane Risk of Bias version 1 tool) independently and in duplicate. We synthesized the evidence for each outcome using random effects network meta-analyses. We critically appraised the evidence following the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) approach. RESULTS: We analyzed 61 randomized controlled trials (7176 participants, 8 interventions). Sinusitis-related quality of life might improve with INCS rinse (mean difference [MD] -6.83, 95% confidence interval [CI] -11.94 to -1.71) and exhalation delivery system (EDS) (MD -7.86, 95% CI -14.64 to -1.08) compared to placebo (both low certainty evidence). Nasal obstruction symptoms are likely improved when receiving INCS via stent/dressing (MD -0.31, 95% CI -0.54 to -0.08), spray (MD -0.51, 95% CI -0.61 to -0.41), and EDS (MD -0.35, 95% CI -0.51 to -0.18) (all moderate to high certainty) compared to placebo. We found no important differences in adverse effects among interventions (moderate certainty for INCS spray, very low to low certainty for others). CONCLUSIONS: Multiple delivery forms of INCS are viable therapeutic options for CRSwNP, resulting in improvement of patient-important outcomes. INCS via stent, spray, and EDS appear to be beneficial across the widest range of considered outcomes.

Cannabis-related allergies: An international overview and consensus recommendations.

Cannabis is the most widely used recreational drug in the world. Cannabis sativa and Cannabis indica have been selectively bred to develop their psychoactive properties. The increasing use in many countries has been accelerated by the COVID-19 pandemic. Cannabis can provoke both type 1 and type 4 allergic reactions. Officially recognized allergens include a pathogenesis-related class 10 allergen, profilin, and a nonspecific lipid transfer protein. Other allergens may also be relevant, and recognition of allergens may vary between countries and continents. Cannabis also has the potential to provoke allergic cross-reactions to plant foods. Since cannabis is an illegal substance in many countries, research has been hampered, leading to challenges in diagnosis since no commercial extracts are available for testing. Even in countries such as Canada, where cannabis is legalized, diagnosis may rely solely on the purchase of cannabis for prick-to-prick skin tests. Management consists of avoidance, with legal issues hindering the development of other treatments such as immunotherapy. Education of healthcare professionals is similarly lacking. This review aimed to summarize the current status of cannabis allergy and proposes recommendations for the future management of this global issue.

Psychological impacts of coronavirus disease 2019 on people with asthma, allergic rhinitis, and food allergy.

OBJECTIVE: To summarize the current literature of the psychological impacts of coronavirus disease 2019 (COVID-19) on people with allergic diseases and to identify gaps in need of future research. DATA SOURCES: Ovid MEDLINE(R) and Embase Classics + Embase from 1947 to present (October 18, 2021) were searched using a search strategy that included the following keywords: allergic diseases, covid*, and psychological disorders. STUDY SELECTIONS: Primary manuscripts and abstracts using online and telephone surveys, mixed-method studies capturing patient and caregiver experiences, case studies, and published guidelines from allergic disease-specific expert groups were included. RESULTS: People with asthma and other chronic respiratory conditions are at higher risk of negative psychological outcomes, and risk factors include asthma severity, female sex, and previous history of anxiety and depression, likely owing to the perceived risk of severe disease from COVID-19. One study identified that people with allergic rhinitis had significantly high anxiety and depression scores compared with healthy controls (both, P < .001). The psychological impacts of food allergy during COVID-19 were most strongly felt by parents and caregivers. Similarly, parents of children with asthma experienced substantial psychological burden. CONCLUSION: COVID-19 had a considerable psychological impact on patients with asthma. Limited data have been published on the mental health impacts of COVID-19 on patients with allergic rhinitis and food allergy. As COVID-19 research continues to evolve and the literature captures later stages of the pandemic, it is important that physicians be aware of the potential coincidence of mental illness and chronic allergic diseases and refer these patients, and their caregivers, to appropriate resources while also continuing to manage their allergic disease(s).

Anxiety in adults with allergic rhinitis during the coronavirus disease 2019 pandemic: A Canadian perspective.

BACKGROUND: Despite the symptom overlap between allergic rhinitis (AR) and coronavirus disease 2019 (COVID-19), pandemic-time anxiety in people with AR remains an area of limited study. OBJECTIVE: To assess the AR-anxiety relationship in the unique context of the COVID-19 pandemic from a Canadian perspective. METHODS: The COVID-19 Associated Anxiety in patients with Asthma and AR Experiencing Symptoms survey was distributed on the "Qualtrics XM" platform, with 835 adult participants responding to the first iteration from April to August 2020. Anxiety was assessed on the Generalized Anxiety Disorder Assessment-7 (GAD-7), and AR burden of disease was assessed on the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). All analyses were conducted using IBM SPSS Statistics 27. RESULTS: High levels of anxiety were found, with 28.0% of the AR group and 27.5% of the control group meeting the diagnostic criteria for generalized anxiety disorder. After controlling for covariates, AR status had no significant predictive effect on GAD-7 in a hierarchal multiple regression model (ΔR2 = .00, P = .69). In the AR subgroup, there were significant positive correlations between anxiety and burden of disease for the total RQLQ score and all 7 domain scores (P < .001 for all), with the non-nose or eye symptom domain having the strongest correlation (r = .63). After controlling for covariates, total RQLQ score had a predictive effect on GAD-7 in a hierarchal multiple regression model (ΔR2 = .049, P < .001). CONCLUSION: High levels of anxiety exist during the COVID-19 pandemic regardless of AR status, indicating the importance of early anxiety screening in all patients. This study also highlights the importance of non-nose or eye symptoms in AR management.

Impact of cannabis knowledge and attitudes on real-world practice.

BACKGROUND: Increased cannabis consumption worldwide challenges allergists because of an upsurge in cannabis allergy and need to discuss cannabis with patients. OBJECTIVE: To determine the knowledge, attitudes, and practices regarding cannabis among allergists and their approach to recognizing and diagnosing suspected cannabis allergy. METHODS: The International Allergist Canna Knowledge, Attitudes, and Practices Survey was completed by members from 3 International Allergy Societies. Survey questions included the following: 13 on cannabis attitudes, 7 on cannabis knowledge, and 4 on real-world allergy practices. Knowledge level was dichotomized and Statistical Package for the Social Sciences TwoStep Cluster Analysis grouped participants by attitudes. Multivariate analysis determined the relationship of knowledge and attitude to practice delivery. RESULTS: Of 570 eligible surveys started, 445 (78.1%) were completed. Participants were 49.7% of female sex, 65.9% aged 24 to 56 years, approximately 70% in practice for more than or equal to 10 years, and 29.2% practicing in an area where cannabis use is illegal. Of the respondents, 43.1% reported consulting on patients with suspected cannabis allergy and 54.7% had undertaken skin prick testing, in vitro cannabis testing, or both. Statistically significant differences were found between the 3 societies for most variables analyzed. Analysis of attitudes revealed 3 clusters named Traditional, Progressive, and Unsure. Those with more progressive attitudes toward cannabis and who had more knowledge were more comfortable speaking to patients about cannabis and more often asked patients on how often and how they used cannabis (all P < .001). CONCLUSION: Varying knowledge and attitudes toward cannabis affecting comfort communicating with patients about cannabis were found in members of 3 allergy societies supporting the need for more cannabis research and education.

Technical standards in allergen exposure chambers worldwide - an EAACI Task Force Report.

Allergen exposure chambers (AECs) can be used for controlled exposure to allergenic and non-allergenic airborne particles in an enclosed environment, in order to (i) characterize the pathological features of respiratory diseases and (ii) contribute to and accelerate the clinical development of pharmacological treatments and allergen immunotherapy for allergic disease of the respiratory tract (such as allergic rhinitis, allergic rhinoconjunctivitis, and allergic asthma). In the guidelines of the European Medicines Agency for the clinical development of products for allergen immunotherapy (AIT), the role of AECs in determining primary endpoints in dose-finding Phase II trials is emphasized. Although methodologically insulated from the variability of natural pollen exposure, chamber models remain confined to supporting secondary, rather than primary, endpoints in Phase III registration trials. The need for further validation in comparison with field exposure is clearly mandated. On this basis, the European Academy of Allergy and Clinical Immunology (EAACI) initiated a Task Force in 2015 charged to gain a better understanding of how AECs can generate knowledge about respiratory allergies and can contribute to the clinical development of treatments. Researchers working with AECs worldwide were asked to provide technical information in eight sections: (i) dimensions and structure of the AEC, (ii) AEC staff, (iii) airflow, air processing, and operating conditions, (iv) particle dispersal, (v) pollen/particle counting, (vi) safety and non-contamination measures, (vii) procedures for symptom assessments, (viii) tested allergens/substances and validation procedures. On this basis, a minimal set of technical requirements for AECs applied to the field of allergology is proposed.

Future of allergic rhinitis management.

OBJECTIVE: To present a comprehensive, clinically focused scoping review of therapeutic agents and practices comprising the future of allergic rhinitis (AR) management. DATA SOURCES: A review of the published literature was performed using the PubMed database, published abstracts, and virtual presentations from scientific meetings and posted results on ClinicalTrials.gov. STUDY SELECTIONS: Primary manuscripts with trial results, case reports, case series, and clinical trial data from ClinicalTrials.gov, PubMed, and articles highlighting expert perspectives on management of AR were selected. RESULTS: Telemedicine, social media, and mHealth facilitate integrated care for AR management. Pharmacotherapy remains the standard of care for AR management; however, treatment combinations are recommended. Intralymphatic immunotherapy and peptide immunotherapy are the most promising new allergen immunotherapy options. Studies of targeted biologics for AR are ongoing. Probiotics may be beneficial for AR management, particularly Bifidobacterium spp, and as an add-on to allergen immunotherapy. CONCLUSION: AR is a chronic and often comorbid condition that requires integrated care for optimal management. New formulations and combinations of existing AR therapies are the most promising and merit future research.

Insights into allergic risk factors from birth cohort studies.

OBJECTIVE: To present an update of birth cohort study designs and their contributions to allergic risk. DATA SOURCES: The PubMed database was used to search for relevant articles. STUDY SELECTIONS: Peer-reviewed prospective and retrospective studies involving the assessment of allergy using human birth cohorts between 2014 and 2021 were evaluated. RESULTS: Parental history of allergic diseases, especially in cases involving both parents, is associated with increased risk of allergy. Exposure to prenatal and postnatal smoking and limited diet diversity were associated with increased allergic burden. The impact of early-life infections and antibiotics on disease development may be associated with the onset of asthma, though this remains debated. Cohort studies also revealed that the mode of delivery and breastfeeding duration affect the odds ratio of asthma and eczema development. Household exposures, including pets, house dust mites, and scented aeroallergens may confer protective effects, whereas high air pollution exposure and low socioeconomic status may be risk enhancing. Exposure to antibiotics during early life may be associated with increased asthma risk, whereas viral infections may lead to disease protection, though the impact of the coronavirus disease 2019 pandemic on allergic risk is yet to be understood. CONCLUSION: Although evaluating the risk of allergic disease development is complex, clinicians can apply these insights on the multifactorial nature of atopy to better understand and potentially mitigate disease development.

Comparative nasal airflow with loratadine-pseudoephedrine and fluticasone nasal spray for allergic rhinitis.

BACKGROUND: Although it is known that oral antihistamine-pseudoephedrine combination tablets have a faster onset than intranasal corticosteroid sprays in the treatment of allergic rhinitis after the first dose, the magnitude of change has not been measured in a comparative manner. Furthermore, the sensation of sprayed liquid in the nose may lead patients to mistakenly believe that intranasal steroid sprays work instantly. OBJECTIVE: To evaluate, numerically, nasal airflow changes provided by a single dose of loratadine-pseudoephedrine tablet (LP) and fluticasone propionate nasal spray (FP) in participants experiencing allergic rhinitis symptoms, including nasal congestion. METHODS: This single-center, double-blinded, placebo-controlled, crossover study evaluated objective nasal airflow changes in patients with a documented sensitivity to ragweed pollen. Participants were randomized to receive 1 of 4 treatment sequences, and their peak nasal inspiratory flow (PNIF) was measured in a span of 4 hours after pollen exposure in an environmental exposure unit. RESULTS: Average change in PNIF was 31% with LP in the course of the study, significantly greater than with placebo and FP (12% and 15%, respectively; P < .001). Nevertheless, FP did not produce a significant change compared with its placebo. At hour one post-dose, LP had a clinically significant 31% increase in PNIF, whereas FP only yielded an 8.6% increase (P < .001). Measurable nasal airflow improvements are associated with the opening of nasal passages, allowing congested patients to breathe more freely. CONCLUSION: A single dose of LP quickly and significantly (P < .001) improved nasal airflow after ragweed pollen challenge in an environmental exposure unit. Comparatively, FP did not display this same benefit. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03443843.

Environmental exposure unit simulates natural seasonal birch pollen exposures while maximizing change in allergic symptoms.

BACKGROUND: Birch pollen is a prevalent aeroallergen during the springtime allergy season. In field studies, variable allergen exposure and environmental factors can affect data quality while environmental exposure units (EEUs) deliver controlled, standardized, and reproducible allergen exposures. OBJECTIVE: To inform study design for EEU trials evaluating antiallergic therapies. METHODS: In this prospective study, 76 participants with birch allergy experienced 3 exposures to birch pollen: (1) an out-of-season EEU challenge (two 3-hour sessions on consecutive days); (2) a natural seasonal exposure; and (3) an in-season EEU challenge (3-hour exposure for 2 weeks after birch pollen season initiation). RESULTS: The total nasal symptom score, total ocular symptom score, and total symptom score (TSS = total nasal symptom score plus total ocular symptom score) were assessed every 30 minutes and daily during EEU and natural exposures. A high association between TSSs and day 2 of the out-of-season and in-season EEU challenges was noted, with a good association between the maximum TSS during the natural and in-season EEU challenges, and natural season and day 2 of the out-of-season EEU challenge (P < .001 for all). Participants had higher maximum change from the baseline TSS during day 2 of the out-of-season EEU challenge (12.4) vs the following: (1) first day (9.8); (2) in-season EEU challenge (8.4); and (3) natural seasonal exposure (7.6) (P < .001 for all). CONCLUSION: A strong association was seen between the presence of allergy symptoms and exposure to birch pollen in the EEU (maximum change in symptom scores during day 2) and in the field. A hybrid trial design may be useful to demonstrate the clinical efficacy of novel antiallergic therapies requiring fewer participants and shorter timelines and expediting treatment availability.

Idiopathic anaphylaxis: Diagnosis and management.

Introduction: Idiopathic anaphylaxis (IA) is a diagnosis of exclusion and is based on the inability to identify a causal relationship between a trigger and an anaphylactic event, despite a detailed patient history and careful diagnostic assessment. The prevalence of IA among the subset of people who experienced anaphylaxis is challenging to estimate and varies widely, from 10 to 60%; most commonly noted is ∼20% in the adult anaphylactic population. Comorbid atopic conditions, such as food allergy, allergic rhinitis, and asthma, are present in up to 48% of patients with IA. Improved diagnostic technologies and an increased understanding of conditions that manifest with symptoms associated with anaphylaxis have improved the ability to determine a more accurate diagnosis for patients who may have been initially diagnosed with IA. Methods: Literature search was conducted on PubMed, Google Scholar and Embase. Results: Galactose-α-1,3-galactose (α-gal) allergy, mast cell disorders, and hereditary a-tryptasemia are a few differential diagnoses that should be considered in patients with IA. Unlike food allergy, when anaphylaxis occurs within minutes to 2 hours after allergen consumption, α-gal allergy is a 3-6-hour delayed immunoglobulin E-mediated anaphylactic reaction to a carbohydrate epitope found in red meat (e.g., beef, lamb, pork). The more recently described hereditary α-tryptasemia is an inherited autosomal dominant genetic trait caused by increased germline copies of tryptase human gene alpha-beta 1 (TPSAB1), which encodes α tryptase and is associated with elevated baseline serum tryptase. Acute management of IA consists of carrying an epinephrine autoinjector to be administered immediately at the first signs of anaphylaxis. Long-term management for IA with antihistamines and other agents aims to potentially reduce the frequency and severity of the anaphylactic reactions, although the evidence is limited. Biologics are potentially steroid-sparing for patients with IA; however, more research on IA therapies is needed. Conclusion: The lack of diagnostic criteria, finite treatment options, and intricacies of making a differential diagnosis make IA challenging for patients and clinicians to manage.

Allergy to oak pollen in North America.

Background: Oak pollen is an important allergen in North America. The genus Quercus (oak) belongs to the family Fagaceae under the order Fagales. Objective: The objective of this article was to narratively review the oak pollen season, clinical and epidemiologic aspects of allergy to oak pollen, oak taxonomy, and oak allergen cross-reactivity, with a focus on the North American perspective. Methods: A PubMed literature review (no limits) was conducted. Publications related to oak pollen, oak-related allergic rhinitis with or without conjunctivitis, and oak-related allergic asthma were selected for review. Results: Oak species are common throughout the United States and contribute up to 50% to overall atmospheric pollen loads. Mean peak oak pollen counts can reach >2000 grains/m³. The start of the oak pollen season generally corresponds to the seasonal shift from winter to spring based on latitude and elevation, and may begin as early as mid February. The duration of the season can last > 100 days and, in general, is longer at lower latitudes. In the United States, ∼30% of individuals with allergy are sensitized to oak. The oak pollen season correlates with increased allergic rhinitis symptom-relieving medication use and asthma-related emergency department visits or hospitalizations. Oak falls within the birch homologous group. Extensive immunologic cross-reactivity has been demonstrated between oak pollen and birch pollen allergens, and, more specifically, their major allergens Que a 1 and Bet v 1. The cross-reactivity between oak and birch has implications for allergy immunotherapy (AIT) because guidelines suggest selecting one representative allergen within a homologous group for AIT, a principle that would apply to oak. Conclusion: Allergy to oak pollen is common in North America and has a substantial clinical impact. Oak pollen allergens are cross-reactive with birch pollen allergens, which may have implications for AIT.

Persistence of the clinical effect of grass allergen peptide immunotherapy after the second and third grass pollen seasons.

BACKGROUND: Grass allergen peptides are in development for the treatment of grass pollen-induced allergic rhinoconjunctivitis. A previous randomized, placebo-controlled study demonstrated that grass allergen peptides significantly improved total rhinoconjunctivitis symptom scores (TRSSs) after posttreatment challenge (PTC) to rye grass in an environmental exposure unit after 1 intervening grass pollen season (GPS1). OBJECTIVE: We sought to evaluate the efficacy/safety of 4 dosing regimens of grass allergen peptides after a second (GPS2) and third (GPS3) intervening GPS in the environmental exposure unit. METHODS: Eligible subjects who were randomized in the parent study (GPS1) during the first year of recruitment were invited to participate in GPS2 and GPS3, which took place 1 and 2 years after treatment cessation, respectively. Participants were not treated further, and both participants and study personnel remained blinded. The primary efficacy end point was the change in mean TRSS (reported every 30 minutes) from GPS1 baseline to the follow-up PTC calculated across all time points over days 2 to 4 for GPS2 and across hours 1 to 3 over days 2 to 4 for GPS3. Secondary efficacy end points and safety were also assessed. RESULTS: One hundred twenty-two and 85 participants were enrolled in GPS2 and GPS3, respectively. A numerically greater, but not statistically significant improvement from baseline in mean TRSS at PTC was observed in the group receiving one 6-nmol intradermal injection every 2 weeks for 14 weeks group compared with the placebo at GPS2 (-6.0 vs -3.6, P = .0535) and GPS3 (-6.2 vs -3.6, P = .1128). Similar findings were observed for the group receiving one 6-nmol intradermal injection every 2 weeks for 14 weeks at GPS3 (-6.4 vs -3.6, P = .0759). No adverse safety signals were detected. CONCLUSION: Treatment with grass allergen peptides led to an improvement in allergic rhinoconjunctivitis symptoms after 3 intervening GPSs, corresponding to up to 2 years off treatment.