Emergency department anaphylaxis: A review of 142 patients in a single year

Drug Allergies in Older Adults: A Major Problem in a Specific Population

INTRODUCTION

The use of medications in older adults is increasing due to the prevalence of chronic diseases. Data on the characteristics of drug allergies (DAs) in older adults are limited. This study investigated the prevalence and clinical characteristics of DAs in patients aged 65 years and older.

METHODS

Patient records were examined retrospectively between January 2018 and December 2022. The study included 200 patients aged ≥18 years who met the criteria for diagnosis of type B drug reactions. The patients were divided into two groups: the adult group (18-64 years) and the older adult group (≥65 years).

RESULTS

Advanced age was an independent risk factor for the development of anaphylaxis and immediate and delayed hypersensitivity reactions (odds ratio [OR] = 4.296; 95% confidence interval [CI] = 1.700-10.855; p = 0.002, OR = 3.800; 95% CI = 1.247-11.579; p = 0.019, OR = 3.028; 95% CI = 1.248-7.343; p = 0.014, respectively). Older adults had higher rates of comorbidities and polypharmacy (p < 0.001, p = 0.016, respectively), beta-lactam antibiotic allergy (p < 0.001), and hospitalization and intensive care unit (ICU) admission for DAs (p = 0.024, p = 0.045, respectively).

CONCLUSION

Older age was an independent risk factor for anaphylaxis and both immediate and delayed reactions. Older adults had higher rates of comorbidities, polypharmacy, beta-lactam antibiotic triggers, and hospitalization and ICU admission.

Developing an AI-based prediction model for anaphylactic shock from injection drugs using Japanese real-world data and chemical structure-based analysis

BACKGROUND

This study aims to develop an AI-based prediction model for injection drugs that cause anaphylactic shock using Japanese Real-World Data (JADER database) and chemical structure-based analysis.

METHODS

Data sourced from the JADER database included adverse drug reaction reports from April 2004 to December 2020. Only drugs with an adverse reaction named "anaphylactic shock" were selected for analysis. For model building, various models were constructed to predict anaphylactic shock-inducing drugs, such as logistic regression, LASSO, XGBoost, RF, SVM, and NNW. These models used chemical properties and structural similarities as feature variables. Dimension reduction was applied using principal component analysis. The dataset was split into training (80%) and validation (20%) sets. Six different models were trained and optimized through fivefold cross-validation.

RESULTS

From April 2004 to December 2020, 947 drugs with the adverse reaction name "anaphylactic shock" were extracted from the JADER database. 320 drugs were excluded due to analytical challenges, and another 400 were removed due to their administration route. 227 drugs were finalized as target medicines. For model validation, the performance of each model was evaluated based on metrics like AUCs of ROC curve, sensitivity, and specificity. Additionally, two ensemble models, constructed from the six models were assessed using bootstrap sampling. Interestingly, it was identified that mepivacaine structural similarity had the highest importance in the final model.

CONCLUSIONS

The study successfully developed an AI-based prediction model for anaphylactic shock inducing-injection drugs. The model would offer potential for drug safety evaluation and anaphylactic shock risk assessment.

Anaphylaxis in a Swiss university emergency department: clinical characteristics and supposed triggers

BACKGROUND

Anaphylaxis is the most severe form of acute systemic and potentially life-threatening reactions triggered by mast and basophilic cells. Recent studies show a worldwide incidence between 50 and 112 occurrences per 100,000 person-years. The most identified triggers are food, medications, and insect venoms. We aimed to analyze triggers and clinical symptoms of patients presenting to a Swiss university emergency department for adults.

METHODS

Six-year retrospective analysis (01/2013 to 12/2018) of all patients (> 16 years of age) admitted with moderate or severe anaphylaxis (classification of Ring and Messmer ≥ 2) to the emergency department. Patient and clinical data were extracted from the electronic medical database of the emergency department.

RESULTS

Of the 531 includes patients, 53.3% were female, the median age was 38 [IQR 26-51] years. The most common suspected triggers were medications (31.8%), food (25.6%), and insect stings (17.1%). Organ manifestations varied among the different suspected triggers: for medications, 90.5% of the patients had skin symptoms, followed by respiratory (62.7%), cardiovascular (44.4%) and gastrointestinal symptoms (33.7%); for food, gastrointestinal symptoms (39.7%) were more frequent than cardiovascular symptoms (36.8%) and for insect stings cardiovascular symptoms were apparent in 63.8% of the cases.

CONCLUSIONS

Average annual incidence of moderate to severe anaphylaxis during the 6-year period in subjects > 16 years of age was 10.67 per 100,000 inhabitants. Medications (antibiotics, NSAID and radiocontrast agents) were the most frequently suspected triggers. Anaphylaxis due to insect stings was more frequently than in other studies. Regarding clinical symptoms, gastrointestinal symptoms need to be better considered, especially that initial treatment with epinephrine is not delayed.

Airway Involvement and Intervention in Non-ACE-Inhibitor-Induced Angioedema

OBJECTIVES

Characterize the presentation of patients with non-angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema and determine risk factors associated with patient disposition and possible need for airway intervention.

METHODS

The medical records of adult patients in the Emergency Department (ED) and diagnosed with non-ACEI-induced angioedema over 4.5 years were included. Demographics, vital signs, etiology, timeline, presenting symptoms, physical exam including flexible laryngoscopy, medical management, and disposition were examined. Statistical analyses were conducted using SPSS V 23.0 software calculating and comparing means, standard deviations, medians, and correlation of categorical and ordinate variables.

RESULTS

A total of 181 patients with non-ACEI-induced angioedema were evaluated with flexible laryngoscopy by otolaryngology. Notably, 11 patients (6.1%) required airway intervention and were successfully intubated. Statistically significant factors (p ≤ 0.05) associated with airway intervention included the diastolic blood pressure (DBP) and mean arterial pressure (MAP) (p = 0.006 and 0.01 respectively), symptoms of dysphonia (p = 0.018), the presence of oropharyngeal, supraglottic, and hypopharyngeal edema (p ≤ 0.001 for each site), and the number of edematous anatomic subsites documented on physical exam (p < 0.001). Other patient demographics, prior history of angioedema, heart rate, systolic blood pressure, symptom onset, number of symptoms at presentation, and medication administered in the ED did not correlate with airway intervention.

CONCLUSION

Dysphonia, DBP, MAP, anatomic location of edema and edema in multiple sites are associated with airway intervention and a higher level of care in non-ACEI-induced angioedema and can be useful in risk assessment in patient management.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2282-2287, 2024.

A retrospective audit of adult and paediatric anaphylaxis management from two Australian metropolitan mixed emergency departments

BACKGROUND

Anaphylaxis is a potentially life-threatening allergic reaction, with presentations to emergency departments (EDs) increasing across Australia. Understanding the features of those presenting with anaphylaxis and aspects related to its optimal clinical management across the admission, treatment and discharge settings is needed to minimise its impact. We aimed to evaluate the nature and management of presentations related to anaphylaxis across two Australian EDs.

METHODS

Retrospective audit of paediatric and adult patients presenting to a community or tertiary level ED with anaphylaxis from 1 May 2018 to 30 April 2019. Data extracted from medical records included demographic characteristics, causative agents, clinical features, treatments administered across community, ambulance or ED settings, as well as post-discharge care arrangements including provision of Adrenaline Auto-Injector (AAI) and Allergy/Anaphylaxis Action Plan (AAP).

RESULTS

A total of 369 (107 paediatric and 262 adult) ED presentations were identified. A total of 94 (36%) adult and 46 (43%) paediatric patients received pre-hospital adrenaline, with a further 91 (35%) adult and 29 (27%) paediatric patients receiving a dose of adrenaline in the ED. The most commonly administered treatment in ED were corticosteroids, given to 157 (60%) adult and 55 (51%) paediatric patients. Among those requiring an AAI for discharge, 123/210 (59%) adult and 57/91 (63%) of paediatric patients left hospital with an AAI. In contrast, among those requiring an allergy/anaphylaxis action plan (AAP) on discharge, 61/206 (30%) adult and 30/90 (33%) of paediatric patients left hospital with one. Factors associated with an increased likelihood of receiving AAI on discharge in paediatric and adult patients included receipt of any adrenaline, receipt of two or more doses of adrenaline, and longer duration of hospital stay. Adults presenting within business hours were more likely to be discharged with AAI, but no such difference was observed for paediatric patients. Similar findings were evident for provision of AAP on discharge.

CONCLUSION

These findings demonstrate the need to improve assessment and treatment in the ED. In particular, the observed large variability in provision of AAI and AAP on discharge presents opportunities to explore strategies to improve awareness and provision of these critical components of post-discharge care.

Population-based incidence of all-cause anaphylaxis and its development over time: a systematic review and meta-analysis

Introduction

It is extremely difficult to compare studies investigating the frequency of anaphylaxis making it challenging to satisfactorily assess the worldwide incidence rate. Using a systematic review and meta-analysis, this publication aims to determine the current incidence of all-cause anaphylaxis worldwide. Additionally, we investigated whether the incidence of anaphylaxis has changed over time and which factors influence the rates determined by individual studies.

Methods

A literature search was performed in four databases. All articles that reported relevant information on population-based incidence rates of all-cause anaphylaxis were included. The protocol was published on INPLASY, the International Platform of Registered Systematic Review and Meta-analysis Protocols.

Results

The database query and screening process resulted in 46 eligible articles on anaphylaxis. The current incidence worldwide was found to be approximately 46 cases per 100,000 population per year (95% CI 21-103). Evaluating confounding factors showed that studies using allergy clinics and hospitalizations as data source result in comparably low rates. Moreover, children are less prone to develop anaphylaxis compared to the general population. Using a random effects Poisson model we calculated a yearly increase of anaphylaxis incidence by 7.4% (95% CI 7.3-7.6, p < 0.05).

Discussion

This seems to be the first approach to analyze every reported all-cause anaphylaxis incidence rate until 2017 for an at most accurate determination of its epidemiology. Based on these results, future research could investigate the underlying causes for the rising incidence in order find ways to decrease the condition's frequency.

Systematic Review Registration

inplasy.com, identifier [INPLASY202330047].

Characteristics of Pediatric Emergency Department Presentations of Anaphylaxis in Spain

OBJECTIVE

This study aimed to identify the triggers of pediatric anaphylaxis in Spain and to analyze the circumstances of the episode.

METHODS

Planned secondary analysis of a prospective observational multicenter study endorsed by the Spanish Society of Pediatric Emergencies including children aged younger than 18 years diagnosed with anaphylaxis in 7 Spanish pediatric emergency departments (EDs) between 2016 and 2018. We analyzed factors related to the anaphylaxis episode and its management.

RESULTS

Four hundred fifty-three cases were registered, happening mainly at home (295 [65.1%]), school (65 [14.3%]), and street (61 [13.5%]). The median age was 5 years, 143 (31.6%) had previous episodes, and 165 (36.4%) had previously been prescribed an epinephrine autoinjector, used in 40 (24.2% of those prescribed). Two thirds were well-appearing when arriving to the pediatric ED. Food was the trigger in 396 (87.4%). In 349 with a single food involved, the most frequent were milk (108 [30.4%]), nuts (103 [29.0%]), hen's egg (40 [11.3%]), and fish (31 [8.7%]), with variations related to the age of the child.

CONCLUSIONS

Food, especially milk and nuts, are responsible for most anaphylaxis diagnosed in Spanish pediatric EDs. Consideration should be given to improving health education due to the low use of epinephrine autoinjectors.

Positive Predictive Values of Anaphylaxis Diagnosis in Claims Data: A Multi-Institutional Study in Taiwan

Real-world data sources can facilitate essential understanding of the epidemiological features of anaphylaxis. However, the accuracy of case-identifying definitions based on diagnosis codes for anaphylaxis in healthcare databases remains understudied. We conducted a cross-sectional study analyzing claims data from the largest multi-institutional healthcare system in Taiwan during 2017-2021. We included patients with incident anaphylaxis identified by either ICD-10-CM codes for anaphylaxis (Group 1) or ICD-10-CM codes for severe allergic or drug adverse events and additional modifier codes for acute allergy events (Group 2). We randomly selected 20% of the cases to determine the positive predictive value (PPV) of anaphylaxis case-identifying definitions in Groups 1 and 2 after review of electronic medical records by two physicians. From the original cohort (n = 2,176), we randomly selected 433 patients with either a diagnosis of anaphylaxis (Group 1), or a diagnosis of severe allergic and drug adverse events with additional modifier codes for acute allergy events (Group 2). In Group 1, we judged 135 / 170 patients as true anaphylaxis cases, giving a PPV of 79.4% (95% CI: 73.3-85.5). In Group 2, we judged 47 / 263 patients as true anaphylaxis cases, giving a PPV of 17.9% (95% CI: 13.3-22.5). In conclusion, acceptable PPVs were observed when anaphylaxis cases were identified by ICD-10-CM codes for anaphylaxis, but not by ICD-10-CM codes for severe allergic or drug adverse event with additional modifier codes for acute allergy events. Our multi-institutional findings could serve as a fundamental reference for further studies of anaphylaxis based on real-world healthcare databases.

Increased Excretion of Mast Cell Mediator Metabolites During Mast Cell Activation Syndrome

BACKGROUND

One requirement for diagnosing mast cell activation syndrome (MCAS) is an increase, above an established baseline level, in serum tryptase by 20% plus 2 ng/mL. However, there is no consensus of what constitutes excretion of a substantial increase in metabolites from prostaglandin D2, histamine, or leukotriene E4 in MCAS.

OBJECTIVE

Ratios of acute/baseline levels for each urinary metabolite that accompanied tryptase increases of 20% plus 2 ng/mL were determined.

METHODS

Mayo Clinic databases of patients with systemic mastocytosis with or without MCAS were reviewed. Patients with the requisite increase in serum tryptase during MCAS were examined for those who also had acute/baseline measurements of urinary mediator metabolite(s).

RESULTS

Ratios of acute/baseline levels for tryptase and for each urinary metabolite were calculated. For all patients, the average acute/baseline ratio (SD) for tryptase was 4.88 (3.77). Average ratios of urinary mediator metabolites were: leukotriene E4: 35.98 (50.59), 2,3-dinor-11β-prostaglandin F2α: 7.28 (6.89), and N-methyl histamine: 3.2 (2.31). The lowest acute-baseline ratios for each of the three metabolites accompanying a tryptase increase of 20% plus 2 ng/mL were similar, with values of about 1.3.

CONCLUSIONS

To the author's knowledge, this is the largest series of mast cell mediator metabolite measurements during episodes of MCAS that were verified by the requisite tryptase increase above baseline. Unexpectedly, leukotriene E4 showed the greatest average increase. Acute/baseline increase of 1.3 or greater in any of these mediators could be useful for corroborating a diagnosis of MCAS.

Implantable device with magnetically rotating disk for needle-free administrations of emergency drug

Prompt administration of first-aid drugs can save lives during medical emergencies such as anaphylaxis and hypoglycemia. However, this is often performed by needle self-injection, which is not easy for patients under emergency conditions. Therefore, we propose an implantable device capable of on-demand administration of first-aid drugs (i.e., the implantable device with a magnetically rotating disk [iMRD]), such as epinephrine and glucagon, via a noninvasive simple application of the magnet from the outside skin (i.e., the external magnet). The iMRD contained a disk embedded with a magnet, as well as multiple drug reservoirs that were sealed with a membrane, which was designed to rotate at a precise angle only when the external magnet was applied. During this rotation, the membrane on a designated single-drug reservoir was aligned and torn to expose the drug to the outside. When implanted in living animals, the iMRD, actuated by an external magnet, delivers epinephrine and glucagon, similar to conventional subcutaneous needle injections.

Allergy in Cancer Care: Antineoplastic Therapy-Induced Hypersensitivity Reactions

As the backbone of oncological treatments, systemic chemotherapy is still one of the main pawns in cancer care, alone or in combination with newer targeted agents. All chemotherapy agents can be associated with a type of adverse event called an infusion reaction, which can be characterized as unpredictable, non-dose related, and unexplained by the cytotoxic profile of the drug. For some of these events, a certain immunological mechanism can be identified by blood or skin testing. In this case, we can speak of true hypersensitivity reactions that occur as a response to an antigen/allergen. The current work summarizes the main antineoplastic therapy agents and their susceptibility to induce hypersensitivity reactions and also includes a review of clinical presentation, diagnostic methods in hypersensitivity reactions, and perspectives to overcome these negative events in the treatment of patients suffering from various types of cancer.

Incidence, triggering factors, symptoms, and treatment of anaphylaxis in a pediatric hospital

Objective

Assess the incidence of anaphylaxis in the emergency room (ER) of a private pediatric hospital in the city of São Paulo, Brazil, and describe associated factors.

Method

This was a cross-sectional, retrospective, and observational study based on the medical records of patients from 0 to 18 years old seen at the emergency unit during the years of 2016-2019, who had a diagnosis potentially related to anaphylaxis according to ICD-10. All medical records were individually reviewed for the presence of compatible signs and symptoms that identified "possible" cases of anaphylaxis. Cases were considered probable anaphylaxis when medical history was compatible and indicative of anaphylaxis in the opinion of at least 2 allergists.

Results

The incidence of anaphylaxis was 0.013%. Among the 56 patients identified (mean age 4.2 years), food was the most predominant suspected factor (53%), followed by unknown factors (32%), and drugs (12.5%). All patients presented with cutaneous symptoms, 74% with respiratory, and 53% with gastrointestinal. Allergic disease as a comorbidity was found in 39% of the children and 11% had a history of previous anaphylaxis. There were neither cases of syncope or shock, nor deaths. Intramuscular (IM) adrenaline was prescribed in 37.5% of cases.

Conclusions

The incidence of anaphylaxis was low when compared to the worldwide incidence. The severity of most cases was mild, cutaneous symptoms were predominant, and food was the suspected trigger most frequently associated with reactions.

Analysis of Clinical Features of Non-steroidal Anti-inflammatory Drugs Induced Kounis Syndrome

Background

Current knowledge of Kounis syndrome induced by non-steroidal anti-inflammatory drugs (NSAIDs) is based on case reports. This study aimed to investigate the clinical features of Kounis syndrome.

Methods

Case reports of the NSAIDs-induced Kounis syndrome were analyzed by searching Chinese and English databases from 1 January 1950 to 31 January 2022.

Results

The median age of the 45 included patients (28 women) was 51 years (20–80 years). NSAIDs that were the most frequently involved were diclofenac (26.7%, 12/45), metamizole (15.6%, 7/45), and aspirin (13.3%, 6/45). Kounis syndrome occurred mainly within 30 min after administration, with a maximum latency of 1 month. Chest pain (75.6%, 34/45), dyspnea (33.3%, 15/45), and allergic reactions (44.4%, 20/45) were the most common clinical manifestations. Thirty patients (66.7%) had an ST-segment elevation on the electrocardiogram. Echocardiogram and coronary angiography showed abnormalities in 21 patients (75%, 21/28) and 15 patients (37.5%, 15/40). Forty-four patients (97.8%) had a good prognosis after treatment with steroids, antihistamines, and vasodilators.

Conclusion

The possibility of Kounis syndrome should be considered in the presence of coronary artery disease symptoms when taking NSAIDs. Kounis syndrome can be life-threatening. It is essential to identify and treat Kounis syndrome correctly.

Standards for practical intravenous rapid drug desensitization & delabeling: A WAO committee statement

Drug hypersensitivity reactions (DHRs) to intravenous drugs can be severe and might leave patients and doctors in a difficult position where an essential treatment or intervention has to be suspended. Even if virtually any intravenous medication can potentially trigger a life-threatening DHR, chemotherapeutics, biologics, and antibiotics are amongst the intravenous drugs most frequently involved in these reactions. Admittedly, suspending such treatments may negatively impact the survival outcomes or the quality of life of affected patients. Delabeling pathways and rapid drug desensitization (RDD) can help reactive patients stay on first-choice therapies instead of turning to less efficacious, less cost-effective, or more toxic alternatives. However, these are high-complexity and high-risk techniques, which usually need expert teams and allergy-specific techniques (skin testing, in vitro testing, drug provocation testing) to ensure safety, an accurate diagnosis, and personalized management. Unfortunately, there are significant inequalities within and among countries in access to allergy departments with the necessary expertise and resources to offer these techniques and tackle these DHRs optimally. The main objective of this consensus document is to create a great benefit for patients worldwide by aiding allergists to expand the scope of their practice and support them with evidence, data, and experience from leading groups from around the globe. This statement of the Drug Hypersensitivity Committee of the World Allergy Organization (WAO) aims to be a comprehensive practical guide on the technical aspects of implementing acute-onset intravenous hypersensitivity delabeling and RDD for a wide range of drugs. Thus, the manuscript does not only focus on clinical pathways. Instead, it also provides guidance on topics usually left unaddressed, namely, internal validation, continuous quality improvement, creating a healthy multidisciplinary environment, and redesigning care (including a specific supplemental section on a real-life example of how to design a dedicated space that can combine basic and complex diagnostic and therapeutic techniques in allergy).

Changing pattern of pediatric anaphylaxis in Hong Kong, 2010-2019

BACKGROUND

Anaphylaxis is a significant health burden in most Western countries, but there are little published data on the incidence and pattern of anaphylaxis in Asia. We aim to determine the incidence rate and pattern of anaphylaxis over the past decade among the pediatric population in Hong Kong.

METHODS

Medical records of patients presenting with allergy-related symptoms during the period 2010 to 2019 were examined. Pediatric patients aged below 18 years who fulfilled the diagnostic criteria for anaphylaxis laid out by the NIAID/FAAN were analyzed. Incidence rates were calculated using population statistics as the denominator. All information pertaining to the anaphylaxis events and patients' characteristics was retrieved using standardized data collection forms.

RESULTS

The overall 10-year estimated incidence of anaphylaxis was 9.76 per 100,000 person-years, with a rising trend of anaphylaxis incidence across time. Food-induced anaphylaxis accounted for the majority of hospital presentations, of which peanut and shellfish were the top food triggers in our population. Majority of anaphylaxis episodes were of Grade 4 severity, and young age was a significant predictor of severe allergic reactions. Half of the anaphylaxis episodes were misdiagnosed and adrenaline was only utilized in 42.2% of cases, of which 9.4% were administered adrenaline prior to hospital arrival.

CONCLUSIONS

An increasing trend of anaphylaxis incidence over the past decade is evident in Hong Kong children, with a discrepantly low accuracy in diagnosis and suboptimal management of anaphylaxis. There is a pressing need to heighten public and physicians' awareness of the distinctive features of anaphylaxis in the pediatric age-group.

Acute unsolicited adverse events following BNT162b2 vaccine in Saudi Arabia, a real-world data

Background

Acute adverse events and anaphylaxis were reported after the administration of coronavirus disease (COVID-19) mRNA vaccines. We aim to explore the nature and outcome of adverse events following BNT162B2 vaccine in a community vaccination center, Riyadh, Saudi Arabia.

Method

Within 30 min post vaccination, all acute adverse events (AAEs) that occurred before March 31st, 2021, and in people older than 16 years were reviewed (AAE group). We used the case definition of Brighton collaboration on vaccine safety to define anaphylaxis. Patients’ demographics, comorbidities, allergy history, and outcome at disposition were collected. Observation duration after vaccination was short (<15 min) or extended (<3 h). Statistical analysis was performed to study AAEs association with the study variables and outcomes.

Results

Out of 71,221 vaccine recipients, 144 (0.002%) had developed 345 AAEs, at a rate of 48.4 events per 10,000 dose administered. The majority of cases in AAE group were first dose recipients (93.8%) and previously healthy (59%), while the minority had a previous history of allergy (6.3%) or a laboratory-confirmed COVID-19 (4.2%). We found a significant association between female gender and the occurrence of any AAE (p-value = 0.002). Per every 10,000 doses administered, non-anaphylactic AAEs were dizziness (17.8), headache (9.7), nausea (7.1), or syncope (3.2). Only one in every ten AAEs was considered serious and resulted in an extended observation (4.8 per 10,000 doses), but only 1/144 required hospitalization for non-anaphylaxis reasons (0.1 per 10,000 doses). According to the Brighton collaboration definition of anaphylaxis, no single case of high certainty anaphylaxis was recorded. No death was documented in this cohort.

Conclusion

Acute adverse events due to BNT162b2 vaccine were rare and mostly non-serious with a tendency to occur more in women. Further prospective studies on larger vaccine recipients to evaluate the incidence of anaphylaxis in the Saudi population are warranted.

Severe anaphylaxis caused by intravenous anti-cancer drugs

Background

The incidence and risk factors of severe anaphylaxis by intravenous anti‐cancer drugs are unclear, whereas those of milder reactions have been reported.

Study Design

Electronic medical charts of cancer patients who have undergone intravenous chemotherapy between January 2013 and October 2020 in a university hospital were retrospectively reviewed. Non‐epithelial malignancies were also included in the analysis. "Severe anaphylaxis" was judged using Brown's criteria: typical presentation of anaphylaxis and one or more of hypoxia, shock, and neurologic compromise. (UMIN000042887).

Results

Among 5584 patients (2964 males [53.1%], 2620 females [46.9%], median age 66 years), 88,200 person‐day anti‐cancer drug administrations were performed intravenously, and 27 severe anaphylaxes were observed. The causative drugs included carboplatin (14 cases), paclitaxel (9 cases), and cisplatin, docetaxel, trastuzumab, and cetuximab (1 case each). The person‐based lifetime incidence of severe anaphylaxis for patients who received at least one intravenous chemotherapy was 0.48% (27/5584, 95% confidence interval (CI) 0.30%–0.67%) and the administration‐based incidence was 0.031% (27/88,200, 95% CI 0.019%–0.043%). Among 124 patients who received at least 10 carboplatin administrations, 10 patients experienced carboplatin‐induced severe anaphylaxis (10/124, 8.1%, 95% CI 3.0%–13.1%). Carboplatin caused severe anaphylaxis after at least 9‐min interval since the drip started. Thirteen out of 14 patients experienced carboplatin‐induced severe anaphylaxis within a 75‐day interval from the previous treatment. Paclitaxel infusion caused severe anaphylaxis after a median of 5 min after the first drip of the day at a life‐long incidence of 0.93% (9/968, 95% CI 0.27%–1.59%).

Conclusion

We elucidated the high‐risk settings of chemotherapy‐induced severe anaphylaxis.

Clinical effects and factors associated with adverse clinical outcomes of hymenopteran stings treated in a Thai Poison Centre: a retrospective cross-sectional study

OBJECTIVE

To describe clinical effects and outcomes of hymenopteran stings and to explore the non-laboratory factors associated with adverse clinical outcomes, a composite outcome including death, respiratory failure requiring intubation, acute kidney injury (AKI) requiring dialysis and hypotension requiring vasopressor use.

METHODS

A retrospective cross-sectional study was performed at the Ramathibodi Poison Center, a poison centre of a tertiary care hospital in Thailand. All cases of hymenopteran sting consultations from January 2015 to June 2019 were consecutively enrolled, and charts were reviewed. Demographics, initial clinical characteristics and outcomes were collected. Factors associated with adverse clinical outcome were explored.

RESULTS

One hundred and fourteen hymenopteran stings cases (wasp 48%, bee 33%, hornet 14% and carpenter bee 8.8%) were included (median age, 36.5 years (interquartile range 9-55); male 63%). The prevalence of adverse clinical outcomes was 12.3% (95%CI 6.88-12.8). At initial presentation, 100% of cases had local skin reactions, 11.4% were clinical anaphylaxis, and 8% had red urine. Adverse clinical outcomes included death (n = 10), respiratory failure requiring intubation (n = 9), AKI requiring dialysis (n = 6) and hypotension requiring vasopressor use (n = 2). None of the patients with carpenter bee or hornet stings developed adverse clinical outcomes. In univariable analysis, urticaria, wheezing, red urine, wasp sting and sting number > 10 were significantly associated with adverse clinical outcomes. In multivariable analysis, red urine (adjusted OR 11.1 (95% CI 1.57-216)), wheezing (adjusted OR 16.7 (95% CI 1.43-402)) and a number of stings > 10 (adjusted OR 21.5 (95% CI2.13-2557)) were significant.

CONCLUSIONS

Adverse clinical outcomes in hymenopteran stings were not uncommon among cases inquiring to a national Thai poison centre. At initial presentation, red urine, wheezing and a number stings >10 were significantly associated with adverse clinical outcomes. Larger epidemiologic studies are required to confirm these associations.

Effects of Glucocorticoids on Hospitalized Children With Anaphylaxis

BACKGROUND

The benefits of glucocorticoid treatment and recent trends of adjunctive treatments during episodes of anaphylaxis remain unclear.

OBJECTIVES

The aims of this study were to investigate the recent practice patterns and compare the effects of glucocorticoid for children hospitalized with anaphylaxis.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we compared the length of hospital stay, risk of 10-day readmission, and total hospitalization cost between the steroid and nonsteroid groups. We also evaluated recent trends of adjunctive treatments for anaphylaxis.

RESULTS

From 2010 to 2014, the proportions of H1-receptor antagonist use increased from 65.1% to 71.8% (Ptrend = 0.02). The proportions of H2-receptor antagonist use showed an upward trend, ranging from 12.8% to 16.7% (Ptrend = 0.01). No significant change in glucocorticoid use was observed (from 86.7% to 82.6%; Ptrend = 0.08). Stabilized inverse probability-weighting analyses showed that the total length of hospital stay was 0.39 days longer in the steroid group than in the nonsteroid group (95% confidence interval, 0.29-0.49 days). Total hospitalization cost was greater in the steroid group than in the nonsteroid group (difference, ¥3896; 95% confidence interval, ¥2464-¥5562). No significant difference in risk of 10-day readmission was observed between the groups. Instrumental variable analyses showed similar results to stabilized inverse probability-weighting analyses.

CONCLUSIONS

We observed increasing trends of H1- and H2-receptor antagonist use. Length of hospital stay and total hospitalization cost were greater in the steroid group than in the nonsteroid group, whereas readmission risks were similar between the 2 groups.

Novel diagnostic techniques and therapeutic strategies for IgE-mediated food allergy

Background: Immunoglobulin E (IgE) mediated food allergy is a potentially life-threatening condition and represents a heavy burden for patients and their families. Identification of the most suitable way for management of each patient has currently become the primary goal for physicians. Methods: This study reviewed the current literature related to IgE-mediated food allergy. Results: The use of innovative diagnostic tools, such as allergen-specific IgG4 determination, basophil activation test, and component-resolved diagnostics, is currently available to facilitate a proper diagnosis of food allergy. After several decades of "passive clinical management" of the disease, which was based only on avoidance of the allergenic food and the use of epinephrine in the event of anaphylaxis, there has been a switch to active treatment. The most recent evidence-practice guidelines strongly recommend the use of immunotherapy as an effective therapeutic option, particularly in cases of allergy to cow's milk, egg, or peanut. The use of omalizumab, in association with immunotherapy or alone, has been tested in several studies, and results on its effectiveness seemed to be encouraging. Other biologics, such as dupilumab, reslizumab, mepolizumab, and other anticytokines therapies, are being investigated. Another interesting future treatment strategy could be the use of DNA vaccines. Conclusion: In recent years, the management of IgE-mediated food allergy has greatly improved. Knowledge of pathogenetic mechanisms, understanding of the disease course, and the introduction of novel biomarkers led to more accurate diagnoses along with the active treatment of patients.

Clinical Guideline Highlights for the Hospitalist: Anaphylaxis Management in Adults and Children

Anaphylaxis-A 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis RELEASE DATE: April 2020 PRIOR VERSION: Anaphylaxis - a 2019 practice parameter and GRADE analysis DEVELOPER: American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma, and Immunology (ACAAI) FUNDING SOURCE: None TARGET POPULATION: Adult and pediatric patients with anaphylaxis.

Characteristics of Anaphylactic Reactions: A Prospective Observational Study in Japan

BACKGROUND

Anaphylaxis is a systemic, life-threating, allergic reaction in which the clinical features may vary in different populations or due to the allergic triggers. Moreover, the timing and characteristics of biphasic anaphylactic reactions remain unclear.

OBJECTIVES

The purpose of this study was to investigate the clinical characteristics of anaphylaxis cases assessed and treated in Japanese hospitals.

METHODS

This was a prospective observational study of anaphylactic reactions treated in the Emergency Department (ED) of two medical centers from June 2016 to May 2019. All patients diagnosed with anaphylaxis were enrolled in this study. Data collected included patient demographics, symptoms and signs, treatment, clinical course, and suspected triggers. Descriptive statistics and univariate methods were used in the analyses.

RESULTS

We enrolled 302 patients. The median age was 32 years (interquartile range 13-37) and the sample included 182 (60.3%) women. Of the 302 patients, 179 (59.3%) had a history of allergic reactions. The dermatologic, respiratory, gastrointestinal, and cardiac systems were involved in 297 (98.3%), 248 (82.1%), 150 (49.7%), and 55 (18.2%), respectively. Nineteen patients (6.3%) experienced biphasic anaphylactic reactions. Epinephrine use was associated with a lower incidence of biphasic anaphylactic reaction (odds ratio 0.3, 95% confidence interval 0.1-0.9). Time to recurrence of symptoms ranged from 2 to 48 h (median: 10 h).

CONCLUSIONS

In this prospective ED study, foods were the most common triggers of anaphylaxis, and epinephrine administration was associated with a decreased occurrence of biphasic anaphylactic reactions. Over half of patients experiencing biphasic anaphylactic reactions developed symptoms more than 10 h after presentation.

Gender aspects in food allergy

PURPOSE OF REVIEW

The difference of food allergy prevalence between male and female individuals is well documented and should have more impact for personalized diagnosis and management. Although in younger age male sex dominates, in adults more women are affected by food allergies. This sex disparity diminishes again around menopause, underlining the influence of sex hormones, but in addition, also metabolic gender-specific factors and differences in microbiome composition might contribute to the different expression of food allergy in the two genders. The sex-dependent and gender-dependent influence on development of food allergy, disease severity, as well as on social, dietary and neuropsychological factors in studies mainly published within past 18 months are discussed in this review.

RECENT FINDINGS

Sex and gender differences likely play a role in food allergy development, for instance via influence on immune cells and mediators, or on the composition of the microbiome, but only few controlled studies on this specific topic are available.

SUMMARY

Future prospective studies need to clearly take into account the sex and gender difference in order to provide personalized diagnosis, management and treatment of food allergy.

Allergic Anaphylactic Risk in Farming Activities: A Systematic Review

Allergic disorders in the agriculture sector are very common among farm workers, causing many injuries and occupational diseases every year. Agricultural employees are exposed to multiple conditions and various allergenic substances, which could be related to onset of anaphylactic reactions. This systematic review highlights the main clinical manifestation, the allergens that are mostly involved and the main activities that are usually involved. This research includes articles published on the major databases (PubMed, Cochrane Library, Scopus), using a combination of keywords. The online search yielded 489 references; after selection, by the authors, 36 articles (nine reviews and 27 original articles) were analyzed. From this analysis, the main clinical problems that were diagnosed in this category were respiratory (ranging from rhinitis to asthma) and dermatological (eczema, dermatitis, hives) in nature, with a wide symptomatology (from a simple local reaction to anaphylaxis). The main activities associated with these allergic conditions are harvesting or cultivation of fruit and cereals, beekeepers and people working in greenhouses. Finally, in addition to the allergens already known, new ones have emerged, including triticale, wine, spider and biological dust. For these reasons, in the agricultural sector, research needs to be amplified, considering new sectors, new technologies and new products, and ensuring a system of prevention to reduce this risk.

Decreased intracellular histamine concentration and basophil activation in anaphylaxis

BACKGROUND

Histamine is a crucial mediator in the development of anaphylaxis. Although histamine is promptly degraded because of its short half-life in plasma, basophils, which release histamine, remain in the blood for days. To explore basophils as a potential marker and their involvement in the pathogenesis of anaphylaxis, we evaluated the intracellular histamine concentration and the degree of basophil activation in anaphylaxis patients.

METHODS

We conducted a case-control study enrolling anaphylaxis patients and healthy controls. Basophil activation was evaluated by flow cytometry using up-regulation of CD203c expression.

RESULTS

We enrolled 23 patients and measured their blood histamine concentration. Basophil activation was analyzed in seven of 23 patients. The median intracellular histamine concentrations at admission were significantly lower in patients compared with controls (16.4 ng/mL [interquartile range {IQR}, 2.70 to 34.0] vs. 62.3 ng/mL [IQR, 46.0 to 85.1]; p < 0.0001). The median basophil number at admission was also significantly lower in patients compared with controls (2.21 cell/μL [IQR, 0.75 to 12.3] vs. 21.0 cell/μL [IQR, 19.5 to 28.9]; p = 0.027). CD203c expression was not up-regulated in any of the seven patients in vitro, but it was up-regulated in response to anti-IgE stimulation in vitro in two patients at admission and four patients at follow-up.

CONCLUSIONS

Anaphylaxis is associated with a decrease in intracellular histamine, and a reduced number and reactivity of peripheral basophils. Impaired basophil function and a decrease in their number and intracellular histamine levels in the circulation may reflect the underlying mechanism, suggesting that basophils may be a marker of anaphylaxis.

Estrogen and estrogen receptor signaling promotes allergic immune responses: Effects on immune cells, cytokines, and inflammatory factors involved in allergy

Hypersensitivity occurs when the body is stimulated by an antigen, resulting in an immune response, and leads to a physiological disorder or abnormal tissue trauma. Various immune cells, cytokines, and inflammatory mediators are involved in the immune responses related to allergic diseases, which are the core of anaphylaxis. Estrogen receptors are widely distributed in immune cells, which combine with estrogen and participate in allergic responses by affecting immune cells, cytokines, and inflammatory factors. We aimed to summarize the association between estrogen and allergic reactions to provide a scientific basis for understanding and studying the mechanisms of allergic diseases.

Anaphylaxis after vaccination reported to the Vaccine Adverse Event Reporting System, 1990-2016

BACKGROUND

Anaphylaxis, a rare and potentially life-threatening hypersensitivity reaction, can occur after vaccination.

OBJECTIVE

We sought to describe reports of anaphylaxis after vaccination made to the Vaccine Adverse Event Reporting System (VAERS) during 1990-2016.

METHODS

We identified domestic reports of anaphylaxis within VAERS using a combination of Medical Dictionary for Regulatory Activity queries and Preferred Terms. We performed a descriptive analysis, including history of hypersensitivity (anaphylaxis, respiratory allergies, and drug allergies) and vaccines given. We reviewed all serious reports and all nonserious reports with available medical records to determine if they met the Brighton Collaboration case definition for anaphylaxis or received a physician's diagnosis.

RESULTS

During the analytic period, VAERS received 467,960 total reports; 828 met the Brighton Collaboration case definition or received a physician's diagnosis of anaphylaxis: 654 (79%) were classified as serious, and 669 (81%) had medical records available. Of 478 reports in children aged less than 19 years, 65% were male; childhood vaccines were most commonly reported. Of 350 reports in persons aged 19 years or greater, 80% were female, and influenza vaccines were most frequently reported. Overall, 41% of reports described persons with no history of hypersensitivity. We identified 8 deaths, 4 among persons with no history of hypersensitivity.

CONCLUSION

Anaphylaxis after vaccination is rare in the United States and can occur among persons with no history of hypersensitivity. Most persons recover fully with treatment, but serious complications, including death, can occur.

Deciphering biochemical basis of Qingkailing injection-induced anaphylaxis in a rat model by time-dependent metabolomic profiling based on metabolite polarity-oriented analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Qingkailing injection (QKLI) is prepared from eight traditional Chinese medicinal materials or their extracts, which is widely used in clinical practice to treat the upper respiratory inflammation, pneumonia, high fever and viral encephalitis, nonetheless, suffering from serious anaphylaxis.

AIM OF STUDY

This study aims to develop an integrative metabolomics approach for deciphering the biochemical basis of QKLI induced anaphylaxis (QKLI-IA).

MATERIALS AND METHODS

The accuracy of animal modeling, the coverage of detected metabolites and the timeliness of pathological reaction are three key factors for revealing the biochemical basis of disease with untargeted metabolomics. In this study, firstly, the allergic rats (responders) were first screened by passive cutaneous anaphylaxis experiment and then were utilized for modeling. To cover a wider range of metabolites, a large-scale untargeted metabolomics based on metabolites polarity-oriented analysis was performed using ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Then, to evaluate the timeliness of QKLI-IA, a time-dependent metabolomic profiling including the early, mid and late anaphylaxis stages of QKLI-IA, was performed.

RESULTS

Corresponding to early, mid and late anaphylaxis stages of QKLI-IA, 14, 9 and 4 potential biomarkers were identified, respectively. Metabolism pathway analysis revealed that QKLI-IA resulted in dynamic changes in serum amino acid, fatty acid, glycerolipid, and phospholipid metabolisms. Twenty-four metabolites were found with identical fluctuating trends across the three stages of QKLI-IA. The results indicate that the pathogenesis of QKLI-IA is closely related to arachidonic acid metabolism.

CONCLUSION

This research provides a methodology reference for revealing the biochemical basis of disease using metabolomic profiling and offers a new insight to understand the pathogenesis of QKLI-IA.

Evaluation of the left venticular systolic function with the measurement of global longitudinal strain by Speckle tracking echocardiography in anaphylaxis

Background

It is not known how cardiac functions are affected during anaphylaxis.

Objective

Our aim was to measure the cardiac functions shortly after an anaphylaxis attack using a new technique that detects subclinical left ventricular dysfunction.

Methods

Patients in our hospital who experienced anaphylaxis and urticaria (control group) due to any cause were included in the study. Tryptase levels were measured on the third hour of the reaction and 6 weeks later. Left ventricular systolic functions were evaluated with global strain measurement using echocardiography, approximately 4 hours and 6-week post reaction.

Results

Twelve patients were included in the anaphylaxis group (83.3% female; mean age, 43.25 ± 9.9 years). The causes of anaphylaxis were drug ingestion (n = 11) and venom immunotherapy. Eight of the anaphylactic reactions (66.7%) were severe and in 9 reactions (75%) tryptase levels increased. In the anaphylaxis group, strain values measured shortly after anaphylaxis were significantly lower than those calculated 6 weeks later (p < 0.001) and tryptase levels significantly increased (p = 0.002). The strain values measured both shortly after anaphylaxis and 6 weeks later did not differ according to severity of anaphylaxis. In severe anaphylaxis, tryptase levels during anaphylaxis and 6 weeks later were significantly higher (p = 0.019, p = 0.035). The control group evidenced no differences regarding strain and tryptase levels measured at reaction and 6 weeks later. At reaction, in the anaphylaxis group, the tryptase levels were higher and the strain values were lower than those in the urticaria group (p = 0.007, p = 0.003).

Conclusion

Cardiac dysfunction may develop during an anaphylaxis independent of severity of reaction.

Anaphylaxis

Anaphylaxis is an acute, potentially fatal systemic allergic reaction with varied mechanisms and clinical presentations. Although prompt recognition and treatment of anaphylaxis are imperative, both patients and healthcare professionals often fail to recognize and diagnose early signs and symptoms of the condition. Clinical manifestations vary widely; however, the most common signs are cutaneous symptoms, including urticaria, angioedema, erythema and pruritus. Immediate intramuscular administration of epinephrine into the anterolateral thigh is first-line therapy, even if the diagnosis is uncertain. The mainstays of long-term management include specialist assessment, avoidance measures, and the provision of an epinephrine auto-injector and an individualized anaphylaxis action plan. This article provides an overview of the causes, clinical features, diagnosis and acute and long-term management of this serious allergic reaction.

Traditional Chinese medicine and drug-induced anaphylaxis: data from the Beijing pharmacovigilance database

Background Traditional Chinese medicine (TCM) is one of the major triggers for drug-induced anaphylaxis (DIA). Objective We aimed to use the Beijing pharmacovigilance database (BPD) to analyze TCM-induced DIAs in Beijing, China. Setting Drug allergy case reports from the BPD provided by the Beijing Center for Adverse Drug Reaction Monitoring. Method Drug allergy cases from January 2004 to December 2014 were adjudicated. DIA triggered by TCMs were analyzed and compared with those triggered by non-TCM drugs by calculating the reported risk ratio (RRR). We also calculated the RRRs based on severe DIA and death outcomes. Main outcome measure TCMs implicated in DIAs were identified and compared with non-TCM drugs. Results TCMs accounted for 1651 (18.2%) of the total 9074 allergic cases, in which 84.4% (1393/1651) were triggered by injections. Of the TCM allergic cases, 8.5% (141) were DIAs and 7.3% (120) were severe DIAs, and three patients died from injections. The RRR between TCMs and non-TCM-induced DIAs was 0.63. When anaphylactic cases were compared between TCMs to the top four non-TCM drug triggers, RRRs were 0.73 (95% CI 0.61-0.87) for antibiotics, 0.36 (95% CI 0.29-0.44) for radiocontrast agents, 0.55 (95% CI 0.43-0.68) for chemotherapeutics, and 0.29 (95% CI 0.23-0.37) for biologics. Compared to TCM oral or topic formulations, TCM injections had higher RRRs in each of the above comparisons. Conclusion TCM was associated with a decreased risk of DIA compared to non-TCM drugs in drug allergy cases, and the risk was higher for TCM injections.

Analysis of Hymenoptera venom allergy in own material. Clinical evaluation of reactions following stings, in patients qualified for venom immunotherapy

Introduction

Hymenoptera venom allergy (HVA) in some patients occurs with general symptoms involving respiratory and cardiovascular system with anaphylactic shock with constitutes a significant threat to life.

Aim

Assessment of the prevalence of HVA in our own material.

Material and methods

There were 498 patients after a general reaction to wasp and/or bee venom. The survey included questions: the type of stinging insect, body parts stung by insects, profession, frequency of stings by wasps and bees depending on professional activity, places of stings, clinical symptoms using the scale according to Muller, and the treatment following the sting. Among 498 patients, there were 281 women and 217 men.

Results

Wasp stings were more frequent and affected 382 (77%) persons, while bee stings affected 116 (23%) persons. Limbs constituted the most common area of the body stung by both wasps and bees. The sting was more frequent in rural areas and during summer rest. A severe systemic reaction (class III and IV according to Muller) occurred more often in people stung by bees. The most common medications included intravenous glucocorticosteroids, calcium preparations and antihistamines. Intramuscular Adrenaline injection was used in 48% of patients, while only 15% received its prescription as an emergency medication. Bee stings were the most common cause of severe systemic symptoms.

Conclusions

The treatment after the sting in a significant percentage of episodes still deviates from the recommendations of the guidelines, especially in the field of adrenaline recommendations for patients in case of a resting by an insect

Anaphylaxis and Clinical Utility of Real-World Measurement of Acute Serum Tryptase in UK Emergency Departments

BACKGROUND

British guidelines recommend that serial acute serum tryptase measurements be checked in all adults and a subset of children presenting with anaphylaxis. This is the first study reporting the clinical utility of acute serum tryptase in a "real-world" emergency department (ED) setting following the publication of the World Allergy Organization (WAO) criteria for anaphylaxis.

OBJECTIVES

To (1) assess sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of acute serum tryptase in anaphylaxis; (b) determine factors associated with higher acute serum tryptase levels; and (c) audit compliance of acute serum tryptase measurement in the ED.

METHODS

The methods used were retrospective electronic search for ED admissions to 3 acute care hospitals in Birmingham, UK, with anaphylaxis in 2012 using wide search terms followed by scrutiny of electronic clinical records and application of the WAO diagnostic criteria for anaphylaxis. Patients with an acute serum tryptase measurement were included in the analysis.

RESULTS

Acute serum tryptase level was measured in 141 of 426 (33.1%) cases. Mean time from the onset of symptoms to the measurement of acute serum tryptase level was 4 hours 42 minutes (SD ± 05:03 hours) and no patients had serial measurements conforming to British guidelines. Acute serum tryptase level of more than 12.4 ng/mL (75th centile) was associated with a sensitivity, specificity, PPV, and NPV of 28%, 88%, 0.93, and 0.17, respectively. Multiple regression analysis showed that male sex (odds ratio, 2.66; P = .003) and hypotension (odds ratio, 7.08; P = .001) predicted higher acute serum tryptase level.

CONCLUSIONS

An acute serum tryptase level of more than 12.4 ng/mL in an ED setting carries high PPV and specificity, but poor sensitivity and NPV.

Food allergy phenotypes: The key to personalized therapy

Food allergies (FAs) are of increasing public health concern and are characterized by a large spectrum of diseases. Their diversity is well known for immunologic pathways (IgE, non-IgE-mediated FAs) and natural history. Many other factors and patient characteristics are involved including type of food, exposure route, allergic comorbidities, gender, racial and ethnic backgrounds, cofactors and health conditions. Food allergen components and sensitization profiles are also involved in FA phenotypes. A new approach to chronic disorders based on the identification of phenotypes through extensive knowledge of all the complex components is also applicable to FAs and could lead towards integrative care management. Diagnostic biomarkers for FAs are emerging which also contribute to better care modalities. The aim of this article was to highlight current knowledge regarding the phenotypic diversity of FA. This review will focus on IgE-mediated FAs and how identifying phenotypes may help to better understand the pathophysiological complexity, improve diagnosis and lead to personalized treatment strategies.

Development and validation of an algorithm to identify drug-induced anaphylaxis in the Beijing Pharmacovigilance Database

Background Pharmacovigilance databases are utilized to identify serious adverse drug events (ADEs). In China, very few studies have evaluated the validity of using pharmacovigilance databases to identify drug-induced anaphylaxis (DIA). Objective We aimed to develop and validate an algorithm to identify DIA using the Beijing Pharmacovigilance Database (BPD). Setting ADEs from the BPD mainly spontaneously reported from 94 hospitals in Beijing, China. Method Using the diagnoses, we developed an algorithm to identify potential DIAs from the BPD between January 2004 and December 2014. A sample of 500 patients was randomly selected for chart abstraction. Two physician adjudicators assessed whether DIA occurred using the published clinical criteria as the gold standard. Main outcome measure Positive predictive values (PPVs) and 95% confidence intervals of the algorithm and algorithm criteria components were calculated. Results 500 patients (53.2% female; the mean age 48.2 years) with potential DIA were selected using the algorithm. 444 were adjudicated as having anaphylaxis by physicians. The PPV of the overall algorithm was 88.8% (95% CI 86.0-91.6%). PPV for the algorithm only using specific diagnoses of "anaphylactic shock", "anaphylactic reaction", and "anaphylactoid reaction [severe]" was 89.6% (95% CI 86.6-92.4%); this partial algorithm identified 387 (87.2%) DIAs. The diagnosis that identified the most DIAs (83.8%) was "anaphylactic shock", with a PPV of 91.6% (95% CI 88.9-94.3%). Conclusion The overall algorithm identified a greater number of DIAs than the algorithm that only used specific diagnoses; however, its PPV was slightly lower. We were able to identify DIAs with the algorithm we developed.

Genome-wide association study of self-reported food reactions in Japanese identifies shrimp and peach specific loci in the HLA-DR/DQ gene region

Food allergy is an increasingly important health problem in the world. Several genome-wide association studies (GWAS) focused on European ancestry samples have identified food allergy-specific loci in the HLA class II region. We conducted GWAS of self-reported reactivity with common foods using the data from 11011 Japanese women and identified shrimp and peach allergy-specific loci in the HLA-DR/DQ gene region tagged by rs74995702 (P = 6.30 × 10⁻¹⁷, OR = 1.91) and rs28359884 (P = 2.3 × 10⁻¹², OR = 1.80), respectively. After HLA imputation using a Japanese population-specific reference, the most strongly associated haplotype was HLA-DRB1*04:05-HLA-DQB1*04:01 for shrimp allergy (P = 3.92 × 10⁻¹⁹, OR = 1.99) and HLA-DRB1*09:01-HLA-DQB1*03:03 for peach allergy (P = 1.15 × 10⁻⁷, OR = 1.68). Additionally, both allergies’ associated variants were eQTLs for several HLA genes, with HLA-DQA2 the single eQTL gene shared between the two traits. Our study suggests that allergy to certain foods may be related to genetic differences that tag both HLA alleles having particular epitope binding specificities as well as variants modulating expression of particular HLA genes. Investigating this further could increase our understanding of food allergy aetiology and potentially lead to better therapeutic strategies for allergen immunotherapies.

Different clinical features of anaphylaxis according to cause and risk factors for severe reactions

BACKGROUND

Anaphylaxis is a life-threatening allergic reaction. Several studies reported different anaphylactic reactions according to the causative substances. However, a comparison of anaphylaxis for each cause has not been done. This study was conducted to identify common causes of anaphylaxis, characteristics of anaphylactic reaction for each cause and to analyze the factors related to the severity of the reaction.

METHODS

Medical records of patients who visited the emergency room of Ewha Womans University Mokdong Hospital from March 2003 to April 2016 and diagnosed with anaphylactic shock were retrospectively reviewed. We compared the clinical features of anaphylaxis according to the cause. In addition, the severity of anaphylaxis was analyzed and contributing factors for severe anaphylaxis were reviewed.

RESULTS

A total of 199 patients with anaphylaxis were analyzed. Food was the most common cause (49.7%), followed by drug reaction (36.2%), bee venom (10.1%), and unknown cause (4.0%). Cardiovascular symptoms of syncope and hypotension were more common in drug-induced anaphylaxis. The incidence of severe anaphylaxis was the highest in anaphylaxis due to drugs (54.2%). Urticaria and other skin symptoms were significantly more common in food-induced anaphylaxis. Risk factors for severe anaphylaxis included older age, male, and drug-induced one. Epinephrine treatment of anaphylaxis was done for 69.7% and 56.9% of patients with food-induced and drug-induced anaphylaxis, respectively.

CONCLUSIONS

More severe anaphylaxis developed with drug treatment and in males. Low rate of epinephrine prescription was also observed. Male patients with drug induced anaphylaxis should be paid more attention.

Clinical features and treatment of pediatric patients with drug-induced anaphylaxis: a study based on pharmacovigilance data

We assessed the clinical features and treatment of pediatric patients with drug-induced anaphylaxis in clinical settings. Pediatric drug-induced anaphylaxis cases collected by the Beijing Pharmacovigilance Database from 2004 to 2014 were analyzed. A total of 91 cases were identified. Drug-induced anaphylaxis was primarily caused by antibiotics (53%). Children of 0-5 years were more likely to develop cyanosis symptoms than children of 13-17 years (OR = 5.14, 95%CI [1.74, 15.20], P = 0.002). Children of 13-17 years were more likely to develop hypotension than children of 6-12 years (OR = 11.79, 95%CI [2.28, 60.87], P = 0.002), and to manifest both neurological symptoms (OR = 3.56, 95%CI [1.26, 10.08], P = 0.015) and severe anaphylaxis than children of 0-5 years (OR = 15.46, 95%CI [1.85, 129.33], P = 0.002). Supratherapeutic doses of epinephrine were more likely with intravenous (IV) bolus (92%) in contrast to either intramuscular (IM) (36%, OR = 19.25, 95%CI [1.77, 209.55], P = 0.009) or subcutaneous (SC) injections (36%, OR = 19.80, 95% CI [1.94, 201.63], P = 0.005). Only 62 (68%) patients received epinephrine treatment as the first-line therapy.

CONCLUSION

This study demonstrates that antibiotics were the most common cause of pediatric drug-induced anaphylaxis. Children may present with different anaphylactic signs/symptoms based on age groups. Epinephrine is under-utilized and provider education on the proper management of drug-induced anaphylaxis is warranted. What is Known: • The most common causes of anaphylaxis in children are allergies to foods. Drugs are the second most common cause of pediatric anaphylaxis. • IM epinephrine is the recommended initial treatment of anaphylaxis. What is New: • Drug-induced anaphylaxis in pediatric patients has age-related clinical features. • IV bolus epinephrine was overused and associated with supratherapeutic dosing.