Management of Refractory Anaphylaxis: An Overview of Current Guidelines.

In this review, we compare different refractory anaphylaxis (RA) management guidelines focusing on cardiovascular involvement and best practice recommendations, discuss postulated pathogenic mechanisms underlining RA and highlight knowledge gaps and research priorities. There is a paucity of data supporting existing management guidelines. Therapeutic recommendations include the need for the timely administration of appropriate doses of aggressive fluid resuscitation and intravenous (IV) adrenaline in RA. The preferred second-line vasopressor (noradrenaline, vasopressin, metaraminol and dopamine) is unknown. Most guidelines recommend IV glucagon for patients on beta-blockers, despite a lack of evidence. The use of methylene blue or extracorporeal life support (ECLS) is also suggested as rescue therapy. Despite recent advances in understanding the pathogenesis of anaphylaxis, the factors that lead to a lack of response to the initial adrenaline and thus RA are unclear. Genetic factors, such as deficiency in platelet activating factor-acetyl hydrolase or hereditary alpha-tryptasaemia, mastocytosis may modulate reaction severity or response to treatment. Further research into the underlying pathophysiology of RA may help define potential new therapeutic approaches and reduce the morbidity and mortality of anaphylaxis.

Unraveling wasp sensitization in a patient with systemic mastocytosis by CAP-inhibition assay.

Systemic mastocytosis (SM) is a clonal mast cell disorder that can lead to potentially severe anaphylactic reactions. Hymenoptera sting is one of the most frequent triggers of anaphylaxis in these patients, and diagnosis of indolent SM (ISM) without skin involvement (ISMs) is not rare. In this subgroup of patients, venom immunotherapy (VIT) is an effective treatment decreasing subsequent systemic reactions, and lifelong administration is recommended. An individualized diagnosis is necessary to offer the most adequate VIT, and molecular diagnosis (MD) may be useful to discriminate between primary sensitization and cross-reactivity. Nevertheless, other techniques such as ImmunoCAP inhibition assays may be necessary to identify the genuine sensitization to offer the most suitable VIT. We present a male patient with an anaphylactic reaction following several wasp stings. The patient was diagnosed with ISM, and allergy to both Polistes dominula and Vespula sp venom was confirmed. In this scenario, MD did not discriminate between a genuine double sensitization and venom cross-reactivity between both vespids. Thus, CAP-inhibition assay was performed. This case indicated the importance of an accurate diagnosis of hymenoptera venom allergy (HVA). It also highlights the usefulness of CAP-inhibition assays when MD fails to distinguish between genuine double Polistes-Vespula sensitization and cross-reactivity.

Different phenotypes of drug-induced anaphylaxis-Data from the European Anaphylaxis Registry.

BACKGROUND: Drugs are a frequent cause of severe anaphylactic reactions. Here, we analyze a large dataset on drug induced anaphylaxis regarding elicitors, risk factors, symptoms, and treatment. METHODS: Data from the European Anaphylaxis Registry (2007-2019) with 1815 reported cases of drug-induced anaphylaxis were studied accordingly. RESULTS: Drugs are the third most frequent cause of anaphylaxis reported in the Anaphylaxis Registry. Among the eliciting groups of drugs analgesics and antibiotics were far most often reported. Female and senior patients were more frequently affected, while the number of children with DIA was low. DIA patients had symptoms affecting the skin and mucous membranes (n = 1525, 84.02%), the respiratory (n = 1300, 71.63%), the cardiovascular (n = 1251, 68.93%) and the gastrointestinal system (n = 549, 30.25%). Drugs caused significant more severe reactions, occurred more often in medical facilities and led to increased hospitalization rates in comparison to food and insect venom induced anaphylaxis. Adrenaline was used more often in patients with DIA than in anaphylaxis due to other causes. Patients with skin symptoms received more antihistamines and corticosteroids in the acute treatment, while gastrointestinal symptoms led to less adrenaline use. CONCLUSION: The study contributes to a better understanding of DIA, with a large number of cases from Europe supporting previous data, e.g., analgesics and antibiotics being the most frequent culprits for DIA. Female gender and higher age are relevant risk factors and despite clear recommendations, the emergency treatment of DIA is not administered according to the guidelines.

Consistent trajectories of rhinitis control and treatment in 16,177 weeks: The MASK-air® longitudinal study.

INTRODUCTION: Data from mHealth apps can provide valuable information on rhinitis control and treatment patterns. However, in MASK-air®, these data have only been analyzed cross-sectionally, without considering the changes of symptoms over time. We analyzed data from MASK-air® longitudinally, clustering weeks according to reported rhinitis symptoms. METHODS: We analyzed MASK-air® data, assessing the weeks for which patients had answered a rhinitis daily questionnaire on all 7 days. We firstly used k-means clustering algorithms for longitudinal data to define clusters of weeks according to the trajectories of reported daily rhinitis symptoms. Clustering was applied separately for weeks when medication was reported or not. We compared obtained clusters on symptoms and rhinitis medication patterns. We then used the latent class mixture model to assess the robustness of results. RESULTS: We analyzed 113,239 days (16,177 complete weeks) from 2590 patients (mean age ± SD = 39.1 ± 13.7 years). The first clustering algorithm identified ten clusters among weeks with medication use: seven with low variability in rhinitis control during the week and three with highly-variable control. Clusters with poorly-controlled rhinitis displayed a higher frequency of rhinitis co-medication, a more frequent change of medication schemes and more pronounced seasonal patterns. Six clusters were identified in weeks when no rhinitis medication was used, displaying similar control patterns. The second clustering method provided similar results. Moreover, patients displayed consistent levels of rhinitis control, reporting several weeks with similar levels of control. CONCLUSIONS: We identified 16 patterns of weekly rhinitis control. Co-medication and medication change schemes were common in uncontrolled weeks, reinforcing the hypothesis that patients treat themselves according to their symptoms.

Patient-centered digital biomarkers for allergic respiratory diseases and asthma: The ARIA-EAACI approach - ARIA-EAACI Task Force Report.

Biomarkers for the diagnosis, treatment and follow-up of patients with rhinitis and/or asthma are urgently needed. Although some biologic biomarkers exist in specialist care for asthma, they cannot be largely used in primary care. There are no validated biomarkers in rhinitis or allergen immunotherapy (AIT) that can be used in clinical practice. The digital transformation of health and health care (including mHealth) places the patient at the center of the health system and is likely to optimize the practice of allergy. Allergic Rhinitis and its Impact on Asthma (ARIA) and EAACI (European Academy of Allergy and Clinical Immunology) developed a Task Force aimed at proposing patient-reported outcome measures (PROMs) as digital biomarkers that can be easily used for different purposes in rhinitis and asthma. It first defined control digital biomarkers that should make a bridge between clinical practice, randomized controlled trials, observational real-life studies and allergen challenges. Using the MASK-air app as a model, a daily electronic combined symptom-medication score for allergic diseases (CSMS) or for asthma (e-DASTHMA), combined with a monthly control questionnaire, was embedded in a strategy similar to the diabetes approach for disease control. To mimic real-life, it secondly proposed quality-of-life digital biomarkers including daily EQ-5D visual analogue scales and the bi-weekly RhinAsthma Patient Perspective (RAAP). The potential implications for the management of allergic respiratory diseases were proposed.

EAACI guidelines: Anaphylaxis (2021 update).

Anaphylaxis is a clinical emergency which all healthcare professionals need to be able to recognize and manage. The European Academy of Allergy and Clinical Immunology Anaphylaxis multidisciplinary Task Force has updated the 2014 guideline. The guideline was developed using the AGREE II framework and the GRADE approach. The evidence was systematically reviewed and recommendations were created by weighing up benefits and harms. The guideline was peer-reviewed by external experts and reviewed in a public consultation. The use of clinical criteria to identify anaphylaxis is suggested with blood sampling for the later measurement of tryptase. The prompt use of intramuscular adrenaline as first-line management is recommended with the availability of adrenaline autoinjectors to patients in the community. Pharmacokinetic data should be provided for adrenaline autoinjector devices. Structured, comprehensive training for people at risk of anaphylaxis is recommended. Simulation training and visual prompts for healthcare professionals are suggested to improve the management of anaphylaxis. It is suggested that school policies reflect anaphylaxis guidelines. The evidence for the management of anaphylaxis remains mostly at a very low level. There is an urgent need to prioritize clinical trials with the potential to improve the management of patients at risk of anaphylaxis.

Comparison of rhinitis treatments using MASK-air® data and considering the minimal important difference.

BACKGROUND: Different treatments exist for allergic rhinitis (AR), including pharmacotherapy and allergen immunotherapy (AIT), but they have not been compared using direct patient data (i.e., "real-world data"). We aimed to compare AR pharmacological treatments on (i) daily symptoms, (ii) frequency of use in co-medication, (iii) visual analogue scales (VASs) on allergy symptom control considering the minimal important difference (MID) and (iv) the effect of AIT. METHODS: We assessed the MASK-air® app data (May 2015-December 2020) by users self-reporting AR (16-90 years). We compared eight AR medication schemes on reported VAS of allergy symptoms, clustering data by the patient and controlling for confounding factors. We compared (i) allergy symptoms between patients with and without AIT and (ii) different drug classes used in co-medication. RESULTS: We analysed 269,837 days from 10,860 users. Most days (52.7%) involved medication use. Median VAS levels were significantly higher in co-medication than in monotherapy (including the fixed combination azelastine-fluticasone) schemes. In adjusted models, azelastine-fluticasone was associated with lower average VAS global allergy symptoms than all other medication schemes, while the contrary was observed for oral corticosteroids. AIT was associated with a decrease in allergy symptoms in some medication schemes. A difference larger than the MID compared to no treatment was observed for oral steroids. Azelastine-fluticasone was the drug class with the lowest chance of being used in co-medication (adjusted OR = 0.75; 95% CI = 0.71-0.80). CONCLUSION: Median VAS levels were higher in co-medication than in monotherapy. Patients with more severe symptoms report a higher treatment, which is currently not reflected in guidelines.

Behavioural patterns in allergic rhinitis medication in Europe: A study using MASK-air® real-world data.

BACKGROUND: Co-medication is common among patients with allergic rhinitis (AR), but its dimension and patterns are unknown. This is particularly relevant since AR is understood differently across European countries, as reflected by rhinitis-related search patterns in Google Trends. This study aims to assess AR co-medication and its regional patterns in Europe, using real-world data. METHODS: We analysed 2015-2020 MASK-air® European data. We compared days under no medication, monotherapy and co-medication using the visual analogue scale (VAS) levels for overall allergic symptoms ('VAS Global Symptoms') and impact of AR on work. We assessed the monthly use of different medication schemes, performing separate analyses by region (defined geographically or by Google Trends patterns). We estimated the average number of different drugs reported per patient within 1 year. RESULTS: We analysed 222,024 days (13,122 users), including 63,887 days (28.8%) under monotherapy and 38,315 (17.3%) under co-medication. The median 'VAS Global Symptoms' was 7 for no medication days, 14 for monotherapy and 21 for co-medication (p < .001). Medication use peaked during the spring, with similar patterns across different European regions (defined geographically or by Google Trends). Oral H1 -antihistamines were the most common medication in single and co-medication. Each patient reported using an annual average of 2.7 drugs, with 80% reporting two or more. CONCLUSIONS: Allergic rhinitis medication patterns are similar across European regions. One third of treatment days involved co-medication. These findings suggest that patients treat themselves according to their symptoms (irrespective of how they understand AR) and that co-medication use is driven by symptom severity.

Development and validation of combined symptom-medication scores for allergic rhinitis.

BACKGROUND: Validated combined symptom-medication scores (CSMSs) are needed to investigate the effects of allergic rhinitis treatments. This study aimed to use real-life data from the MASK-air® app to generate and validate hypothesis- and data-driven CSMSs. METHODS: We used MASK-air® data to assess the concurrent validity, test-retest reliability and responsiveness of one hypothesis-driven CSMS (modified CSMS: mCSMS), one mixed hypothesis- and data-driven score (mixed score), and several data-driven CSMSs. The latter were generated with MASK-air® data following cluster analysis and regression models or factor analysis. These CSMSs were compared with scales measuring (i) the impact of rhinitis on work productivity (visual analogue scale [VAS] of work of MASK-air® , and Work Productivity and Activity Impairment: Allergy Specific [WPAI-AS]), (ii) quality-of-life (EQ-5D VAS) and (iii) control of allergic diseases (Control of Allergic Rhinitis and Asthma Test [CARAT]). RESULTS: We assessed 317,176 days of MASK-air® use from 17,780 users aged 16-90 years, in 25 countries. The mCSMS and the factor analyses-based CSMSs displayed poorer validity and responsiveness compared to the remaining CSMSs. The latter displayed moderate-to-strong correlations with the tested comparators, high test-retest reliability and moderate-to-large responsiveness. Among data-driven CSMSs, a better performance was observed for cluster analyses-based CSMSs. High accuracy (capacity of discriminating different levels of rhinitis control) was observed for the latter (AUC-ROC = 0.904) and for the mixed CSMS (AUC-ROC = 0.820). CONCLUSION: The mixed CSMS and the cluster-based CSMSs presented medium-high validity, reliability and accuracy, rendering them as candidates for primary endpoints in future rhinitis trials.

Phenotype and risk factors of venom-induced anaphylaxis: A case-control study of the European Anaphylaxis Registry.

BACKGROUND: Venom-induced anaphylaxis (VIA) is a common, potentially life-threatening hypersensitivity reaction associated with (1) a specific symptom profile, 2) specific cofactors, and 3) specific management. Identifying the differences in phenotypes of anaphylaxis is crucial for future management guidelines and development of a personalized medicine approach. OBJECTIVE: This study aimed to evaluate the phenotype and risk factors of VIA. METHODS: Using data from the European Anaphylaxis Registry (12,874 cases), we identified 3,612 patients with VIA and analyzed their cases in comparison with sex- and age-matched anaphylaxis cases triggered by other elicitors (non-VIA cases [n = 3,605]). RESULTS: VIA more frequently involved more than 3 organ systems and was associated with cardiovascular symptoms. The absence of skin symptoms during anaphylaxis was correlated with baseline serum tryptase level and was associated with an increased risk of a severe reaction. Intramuscular or intravenous epinephrine was administered significantly less often in VIA, in particular, in patients without a history of anaphylaxis. A baseline serum tryptase level within the upper normal range (8-11.5 ng/mL) was more frequently associated with severe anaphylaxis. CONCLUSION: Using a large cohort of VIA cases, we have validated that patients with intermediate baseline serum tryptase levels (8-11 ng/mL) and without skin involvement have a higher risk of severe VIA. Patients receiving ß-blockers or angiotensin-converting enzyme inhibitors had a higher risk of developing severe cardiovascular symptoms (including cardiac arrest) in VIA and non-VIA cases. Patients experiencing VIA received epinephrine less frequently than did cases with non-VIA.