Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis.

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.

Idiopathic anaphylaxis yardstick: Practical recommendations for clinical practice.

Anaphylaxis is considered idiopathic when there is no known trigger. The signs and symptoms of idiopathic anaphylaxis (IA) are identical to those of anaphylaxis because of a known cause and can include cutaneous, circulatory, respiratory, gastrointestinal, and neurologic symptoms. Idiopathic anaphylaxis can be a frustrating disease for patients and health care providers. Episodes are unpredictable, and differential diagnosis is challenging. Current anaphylaxis guidelines have little specific guidance regarding differential diagnosis and long-term management of IA. Therefore, the objective of the Idiopathic Anaphylaxis Yardstick is to use published data and the authors' combined clinical experience to provide practical recommendations for the diagnosis and management of patients with IA.

Mast cell disorders and idiopathic anaphylaxis: Evaluation and management.

Background: Our understanding of mast cell activation disorders continues to grow, and our management of these syndromes is improving with this increase in knowledge. Despite these advances, there remain some areas of confusion. Conclusion: In this article, we discussed these areas and offered thoughts about establishing the diagnosis and management.

Electronic Clinical Decision Support System for allergic rhinitis management: MASK e-CDSS.

BACKGROUND: Allergic rhinitis (AR) management has changed in recent years following the switch from the concept of disease severity to the concept of disease control, publication of the AR clinical decision support system (CDSS) and development of mobile health (m-health) tools for patients (eg Allergy Diary). The Allergy Diary Companion app for healthcare providers is currently being developed and will be launched in 2018. It incorporates the AR CDSS to provide evidence-based treatment recommendations, linking all key stakeholders in AR management. OBJECTIVE: To produce an electronic version of the AR CDSS (e-CDSS) for incorporation into the Allergy Diary Companion, to describe the app interfaces used to collect information necessary to inform the e-CDSS and to summarize some key features of the Allergy Diary Companion. METHODS: The steps involved in producing the e-CDSS and incorporating it into the Allergy Diary Companion were (a) generation of treatment management scenarios; (b) expert consensus on treatment recommendations; (c) generation of electronic decisional algorithms to describe all AR CDSS scenarios; (d) digitization of these algorithms to form the e-CDSS; and (e) embedding the e-CDSS into the app to permit easy user e-CDSS interfacing. RESULTS: Key experts in the AR field agreed on the AR CDSS approach to AR management and on specific treatment recommendations provided by Allergy Diary Companion. Based on this consensus, decision processes were developed and programmed into the Allergy Diary Companion using Titanium Appcelerator (JavaScript) for IOS tablets. To our knowledge, this is the first time the development of any m-health tool has been described in this transparent and detailed way, providing confidence, not only in the app, but also in the provided management recommendations. CONCLUSION: The Allergy Diary Companion for providers provides guideline and expert-endorsed AR management recommendations. [MASK paper No 32].

The changing face of anaphylaxis in adults and adolescents.

BACKGROUND: Our institution has published serial studies of adults and adolescents with anaphylactic events. The first series was published in 1993 and the last was published in 2006. It was our perception that the nature of anaphylactic episodes had changed over the 2 decades since the last review. OBJECTIVE: To determine whether the etiologies and presentations of anaphylaxis have changed during the past decade in our population. METHODS: Patient charts were identified based on International Classification of Diseases, Ninth Revision codes for anaphylactic shock. Charts identified were analyzed for clinical symptoms reported, comorbidities, etiology, investigative testing, and subsequent treatment. These cases were categorized as definitive, probable, or idiopathic based on history and results from testing, similar to our prior reports. RESULTS: We identified 281 possible cases, of which 218 met criteria for anaphylaxis. Of these cases, median age was 42 years (range 9-78) and 64% were female. In the review of cases, 85 (39%) were determined to have a definitive etiology, 57 were determined to have a probable etiology (26%), and 76 (35%) were idiopathic. Interestingly, of those with a definitive cause, the most common etiology identified was galactose-α-1,3-galactose, accounting for 28 cases (33%). Foods were the second leading cause, accounting for 24 cases (28%). CONCLUSION: In this follow-up report on anaphylaxis etiology from a single center, the most common etiology was galactose-α-1,3-galactose. This differs greatly from prior reports from our center. Interestingly, the percentage of cases attributed to idiopathic anaphylaxis decreased from 59% in our previous report to 35% in the present report, which could largely be explained by the number of galactose-α-1,3-galactose cases.

Mast Cells and Anaphylaxis.

For half a century, it has been known that the mast cell is the cell responsible for the majority of anaphylactic events. Its mediators, taken as a whole, are capable of producing all of the clinical manifestations of these events. With the discovery of immunoglobulin E (IgE), it was originally felt that the vast majority of anaphylactic episodes were due to antigen coupling with two cell-bound IgE molecules. More recently it has been learned that many episodes are produced by direct activation of mast cells, not involving antigen binding to IgE, and that monomeric IgE under certain conditions can also cause degranulation. Of note--in regard to antigen independent degranulation--are recent reports that the human G-protein-coupled receptor, MRGPRX2, may be the receptor for many drugs and cationic proteins capable of producing direct mast cell degranulation and anaphylactic events.

Nonallergic rhinitis.

Rhinitis is normally defined by the symptoms of nasal congestion, postnasal drainage, rhinorrhea, and sneezing. It has been associated with various pathologic changes, but can occur in the absence of any inflammation. Thus, the diagnosis is based on the clinical presentation. There are no clear-cut criteria to distinguish when rhinitis becomes chronic, but in its chronic form, it can be complex. Chronic forms of rhinitis that occur in the absence of any detectable specific IgE against relevant aeroallergens in its broadest sense can be called chronic nonallergic rhinitis. This review will concentrate on chronic nonallergic rhinitis in its various forms, discussing the epidemiology, underlying mechanisms, and its therapy.

Idiopathic anaphylaxis.

Idiopathic anaphylaxis is not uncommon and can be found in as many as 60% of patients referred to an allergist for anaphylactic events. It is an extremely frustrating condition for patients because they have no means of avoiding a known allergen and events occur spontaneously and unprovoked. The objective of this study was to synthesize and review the medical literature on idiopathic anaphylaxis and present a strategy for diagnosis, prevention, and treatment of episodes. A literature review was performed after a search of PubMed using the key words of idiopathic anaphylaxis. Idiopathic anaphylaxis is more common in adults than in children and in women than in men. The symptoms and signs are identical to those found in other causes of anaphylaxis. Perhaps the most common entities to be considered in the differential diagnosis are somatoform reactions. The two most recent advances in our ability to detect the cause are the discovery that episodes can be caused by mast cell-activating syndromes, systemic mastocytosis, and IgE to galactose-alpha-1,3-galactose. Patients experiencing idiopathic anaphylactic episodes should, if possible, avoid taking drugs that may complicate therapy or worsen a reaction. Fortunately, the vast majority of cases follow a benign course. Although many recurrent episodes of anaphylaxis remain idiopathic, recent advances in our knowledge, especially the description of mast cell-activating disorders and the discovery of anaphylactic reactions to galactose-α-1,3-galactose have allowed us to find causes in events that previously would have been classified as idiopathic. In addition, the majority of such patients exhibit a diminishing frequency of reactions over time and can be managed in a way that prevents mortality and a severe effect on their quality of life.

Clinically relevant effect of a new intranasal therapy (MP29-02) in allergic rhinitis assessed by responder analysis.

BACKGROUND: It is unclear what constitutes a clinically meaningful response for allergic rhinitis (AR) outcomes. The objectives of these post hoc analyses were (1) to define a clinically meaningful response using novel efficacy analyses (including a responder analysis), and (2) to compare the efficacy of MP29-02 [a novel intranasal formulation of azelastine hydrochloride (AZE) and fluticasone propionate (FP)] with commercially available FP, AZE and placebo in seasonal AR (SAR) patients, using these novel analyses. METHODS: 610 moderate-to-severe SAR patients (≥12 years old) were randomized into a double-blind, placebo-controlled, 14-day, parallel-group trial. Change from baseline in the reflective total nasal symptom score (rTNSS) over 14 days was the primary outcome. Post hoc endpoints included the sum of nasal and ocular symptoms (rT7SS), efficacy by disease severity and by predominant nasal symptom, and a set of responder analyses. RESULTS: MP29-02 most effectively reduced rT7SS (relative greater improvement: 52% to FP; 56% to AZE) and both nasal and ocular symptoms irrespective of severity. More MP29-02 patients achieved a ≥30, ≥50, ≥60, ≥75 and ≥90% rTNSS reduction, which occurred days faster than with either active comparator; MP29-02 alone was superior to placebo at the ≥60% (or higher) threshold. One in 2 MP29-02 patients achieved a ≥50% rTNSS reduction and 1 in 6 achieved complete/near-to-complete response. Only MP29-02 was consistently superior to placebo for all patients, whatever their predominant symptom. CONCLUSIONS: MP29-02 provided faster and more complete symptom control than first-line therapies. It was consistently superior irrespective of severity, response criteria or patient-type, and may be considered the drug of choice for moderate-to-severe AR. These measures define a new standard for assessing relevance in AR.

A novel intranasal therapy of azelastine with fluticasone for the treatment of allergic rhinitis.

BACKGROUND: Moderate-to-severe allergic rhinitis (AR) is a challenge to treat, with many patients using multiple therapies and achieving limited symptom control. More effective therapies must be developed and tested in well-controlled, randomized, prospective studies with a direct comparison to current standards. OBJECTIVES: The aim of these studies was to investigate the efficacy of MP29-02 (a novel formulation of azelastine and fluticasone propionate [FP]) in patients with moderate-to-severe seasonal allergic rhinitis (SAR) and to compare its efficacy with 2 first-line therapies (ie, intranasal azelastine and intranasal FP) in this population. METHODS: Three thousand three hundred ninety-eight patients (≥12 years old) with moderate-to-severe SAR were enrolled into 3 multicenter, randomized, double-blind, placebo- and active-controlled, parallel-group trials (MP4002 [NCT00651118], MP4004 [NCT00740792], and MP4006 [NCT00883168]). Each trial was conducted for 14 days during different allergy seasons. The primary efficacy variable was the sum of the morning and evening change from baseline in reflective total nasal symptom score (range, 0-24) over the treatment period. Outcomes for the meta-analysis included efficacy according to disease severity and time to response in relevant responder criteria. RESULTS: In the meta-analysis MP29-02 reduced the mean reflective total nasal symptom score from baseline (-5.7 [SD, 5.3]) more than FP (-5.1 [SD, 4.9], P < .001), azelastine (-4.4 [SD, 4.8], P < .001), or placebo (-3.0 [SD, 4.2], P < .001). This benefit was observed from the first day of assessment, with improvement in each individual nasal symptom, even in the patients with the most severe disease. MP29-02 achieved response consistently days earlier and showed greater efficacy in patients with moderate-to-severe rhinitis than FP and azelastine. CONCLUSIONS: MP29-02 represents a novel therapy that demonstrated superiority to 2 first-line therapies for AR. Patients with moderate-to-severe SAR achieved better control, and their symptoms were controlled earlier with MP29-02 than with recommended medications according to guidelines.

Comparison of intranasal azelastine to intranasal fluticasone propionate for symptom control in moderate-to-severe seasonal allergic rhinitis.

Intranasal corticosteroids are considered the most effective therapy for moderate-to-severe seasonal allergic rhinitis (SAR) and recommended first line in guidelines. It is uncertain whether intranasal antihistamines have comparable efficacy. This study was designed to compare the efficacy of azelastine (AZE; 137 µg/spray) and fluticasone propionate (FP; 50 µg/spray), both given as 1 spray/nostril bid (i.e., approved dosing regimen in the United States), in SAR via a post hoc analysis of data from a previously published direct-comparison study. Six hundred ten moderate-to-severe SAR patients (≥12 years old) were randomized into a double-blind, placebo-controlled, parallel-group trial. The primary efficacy variable was change from baseline in reflective total nasal symptom score (rTNSS (morning and evening), over 14 days. Reflective total ocular symptom score (rTOSS) was a key secondary variable. Reflective total of seven symptom scores (rT7SS [nasal plus ocular symptoms]) and time to ≥50% reduction from baseline in these key parameters were also analyzed. AZE and FP reduced rTNSS from baseline by a similar degree (-3.25 versus -3.84; p = 0.2014). Patients experienced comparable improvement in rTOSS (-2.62 versus -2.17; p = 0.2371) and rT7SS (-5.83 versus -6.05; p = 0.7820). FP was superior to AZE in alleviating rhinorrhea (-1.15 versus -0.87; p = 0.0433), but AZE showed comparable efficacy for all other nasal and ocular symptoms. There was no clinically or statistically significant difference between AZE (-1.17) and FP (-1.43) for reduction in the overall rhinitis quality of life questionnaire score (although FP, but not AZE, significantly differed from placebo). A similar proportion of patients in the AZE and FP groups achieved a 50% reduction in rTNSS. However, more AZE patients (53.0%) exhibited a 50% reduction in rTOSS by day 14 versus FP (39.6%), and ≤3 days faster (p = 0.028). Intranasal AZE (137 micrograms/spray) and intranasal FP (50 micrograms/spray), both 1 spray/nostril b.i.d., had comparable efficacy in symptom control in moderate-to-severe SAR.

Pathophysiology of Immunologic and Nonimmunologic Systemic Reactions Including Anaphylaxis.

There is a myriad of immunologic and nonimmunologic pathways by which the clinical phenotype of anaphylaxis can be produced. An understanding of these pathways is essential for the prevention as well as the treatment of anaphylactic episodes.

The basics of histamine biology.

OBJECTIVE: To review the evolution of our understanding of the basics of histamine biology as it pertains to the treatment of allergic rhinitis. DATA SOURCES: Review articles and original research were retrieved from MEDLINE, OVID, PubMed (1950 to November 2009), personal files of articles, and bibliographies of located articles that addressed the topic of interest. STUDY SELECTION: Key articles were selected that, taken together, provide a history of scientific insight into histamine biology and receptors and mechanism of action of antihistamines. Publications included reviews, treatment guidelines, and clinical studies (primarily randomized controlled trials) of both children and adults. RESULTS: The seminal work on histamine was published in 1910, but histamine was not identified as a mediator of anaphylactic reactions until 1932. Research later showed that histamine is a major mediator responsible for the symptoms of allergic rhinitis, with its activities mediated through 4 G protein-coupled receptors. Most of histamine's effects are exerted through the H1 receptor, but some effects are through the H2 and H3 receptors, and possibly also through the H4 receptor. CONCLUSIONS: We hope that the progress made in understanding the mechanism of action of the histamine response will lead to better targeted treatment options.

Two-week comparison study of olopatadine hydrochloride nasal spray 0.6% versus azelastine hydrochloride nasal spray 0.1% in patients with vasomotor rhinitis.

Olopatadine hydrochloride nasal spray 0.6% (OLO) and azelastine nasal spray 137 micrograms (AZE) are effective in treating allergic rhinitis and AZE is indicated for nonallergic vasomotor rhinitis (VMR). This study evaluates the relative safety and efficacy of OLO and AZE in patients with VMR. This randomized, double-blind, parallel-group, multicenter study compared OLO (an investigational use) with AZE over 14 days in patients (n = 129) ≥12 years of age with chronic VMR. Efficacy included the severity of nasal symptom scores. Safety included adverse events (AEs) and nasal examinations. Patient perceptions of treatment satisfaction and changes in allergy condition were determined using the Treatment Satisfaction Questionnaire for Medication and Patient Global Assessment scores. In the OLO and AZE groups, reflective scores for individual nasal symptoms (nasal congestion, rhinorrhea, postnasal drip, and sneezing) and total nasal VMR symptom scores decreased significantly from baseline to day 14 (p < 0.05). No significant between-group differences were observed (p > 0.05). No serious AEs were reported in either group. Overall, 22 and 20 AEs were reported in the OLO and AZE groups, respectively. The most common AE was taste disturbance, reported by three (5.3%) and six (10.3%) patients in the OLO and AZE groups, respectively. Patients in both groups reported similar treatment satisfaction scores and a majority of patients in both groups perceived an overall improvement in their rhinitis condition. OLO has a similar efficacy and safety profile to AZE for the management of VMR in patients ≥12 years of age.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel.

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.