Epidemiology of anaphylaxis

Associations between gender and health-related quality of life in people with IgE-mediated food allergy and their caregivers: A systematic review

OBJECTIVE

Understanding factors that impact health-related quality of life (HRQL) is essential to inform personalised food allergy management. However, there are inconsistencies about the impact of gender on HRQL in food allergy. This review aimed to collate all investigations of the association between gender and total or subdomain HRQL scores of individuals with food allergy and their caregivers.

DESIGN

This is a narrative systematic review. We descriptively synthesised and compared HRQL outcomes by participant and parent genders according to statistical and clinical significance. Study quality was assessed using the ROBINS-I, inclusive of all domains. Sensitivity analysis of non-interventional studies was conducted using the ROBINS-E.

DATA SOURCES

A systematic search of Medline and Embase databases was conducted on 4 April 2022 and updated on 5 December 2023.

ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they reported original data on the association between any sex and/or gender and HRQL, as measured with any validated instrument, in populations with IgE-mediated food allergy. Interventional and non-interventional studies were eligible.

RESULTS

A comparison of 34 eligible studies (10 interventional and 24 non-interventional) indicated females with food allergy (62.5% of studies of children, 83.3% of studies of adults) and mothers of children with food allergy (50% of studies of caregivers) experienced poorer self-reported baseline HRQL than their counterparts, notably in domains of physical, emotional or food anxiety-related well-being. Gender differences in child HRQL after food allergen immunotherapy were observed. However, selective reporting in included interventional studies meant the direction of this association could not be determined. The proxy-reported total HRQL of participants was not affected by caregiver gender, nor was caregiver HRQL likely impacted by child gender.

CONCLUSIONS

Gender should be considered an important modifier of participant HRQL outcomes in food allergy studies. Purposeful exploration of HRQL in all genders is needed to fully understand the implications of this construct on the lived experience of food allergy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42022329901).

Recent update on the management of anaphylaxis

Anaphylaxis is a life-threatening systemic allergic reaction presenting various clinical manifestations. Its prevalence has increased in almost all age groups and both sexes. Food, venom, and drugs are major causes in both children and adults; a higher prevalence of food-induced anaphylaxis is noted in children, while a higher prevalence of drug-induced anaphylaxis is noted in adults. The pathogenic mechanism is mediated by immunologic and nonimmunologic mechanisms, where mast cells and basophils are key cells that release mediators. A diagnosis of anaphylaxis is mainly based on clinical symptoms and physical findings; however, an increased serum tryptase level is a useful biomarker. Epinephrine is the first-line drug to treat acute symptoms, and an epinephrine auto-injector should be prescribed for each patient. Antihistamines and systemic corticosteroids are used to relieve symptoms. This review updates current issues in the management of anaphylaxis as well as the new guidelines for proper diagnosis and treatment.

Drug-Induced Anaphylaxis in a Vietnamese Pharmacovigilance Database: Trends and Specific Signals from a Disproportionality Analysis

INTRODUCTION

Despite the numerous studies investigating drug-induced anaphylaxis (DIA), understanding and quantitative data analysis in developing countries remain limited. The aim of our study is to describe and quantify DIA using the National Pharmacovigilance Database of Vietnam (NPDV).

METHODS

Spontaneous reporting of adverse drug reactions (ADRs) recorded between 2010 and 2016 were retrospectively analysed to identify DIA reports. The trend and characteristics of DIA cases were described. Multivariate disproportionality analysis was used for signal generation.

RESULTS

Overall, 4873 DIA cases (13.2% of total ADRs) were recorded in the NPDV, 111 of which resulted in death (82% of total ADR-induced deaths) over a 7-year period. There was a remarkable increase in DIA reporting over time (p < 0.001). The incidence rates of DIA reporting per total ADRs and per 100,000 inhabitants remained high (mean rates [95% CI] of 12.06 [9.88-14.24] and 0.77 [0.33-1.20], respectively). Concerning suspected drugs, systemic antibiotics (n = 3318, 68%) were mostly reported with a reporting odds ratio (ROR) and 95% CI of 2.35 [2.20-2.51]. In the case of antibiotic-induced anaphylaxis, the third-generation cephalosporins were predominant (n = 1961, 40.2%, ROR 2.39 [2.24-2.55]). We also noted drugs generally associated with DIA such as contrast agents (ROR 2.43 [2.04-2.88]) and anaesthetics (ROR 4.02 [3.30-4.89]). Furthermore, unexpected signals were observed for alpha-chymotrypsin (ROR 1.75 [1.23-2.44]) and amoxicillin/sulbactam (ROR 1.59 [1.18-2.10]), uncommonly reported in western countries.

CONCLUSION

In recent years, cases of drug-induced DIA have increased in Vietnam, mostly due to antibiotics and third-generation cephalosporins. The inappropriate use of these drugs should be taken into account. Our findings also highlighted typical Vietnamese signals for alpha-chymotrypsin- and amoxicillin/sulbactam-induced anaphylaxis, which may relate to a specific sociological context in resource-limited countries.

A review on Respiratory allergy caused by insects

Hypersensitivity or allergy encompasses a wide range of immunological reactions that generally have adverse consequences involving one or many organ systems of the body. Allergens are usually glycoprotein or chemically complex low molecular weight substances. The common allergens include pollen, fungal spores, house dust mite and house dust, animal danders, drugs, foods, insect emanations, and detritus, etc. Information on the role of insects in respiratory allergy is increasing in the literature. There are about 30 million living species of insects. These insects can broadly be classified as stinging insects, biting insects and non-stinging and non-biting insects. All materials form insets namely wings, scales, saliva; dried feces and venom can cause allergic diseases, such as rhinitis, conjunctivitis, asthma and urticaria. There are wide varieties of insects such as moths, butterflies, bees, wasps, hornets, yellow jackets, flies, beetles, cockroaches, and mosquitoes. Exposure to emanations and detritus of these insects may lead to several allergies in some genetically predisposed individuals. Therefore, it is of interest to review allergies caused by various insect's stings and bites and their adverse effect on the human body.

Increasing trends of anaphylaxis-related events: an analysis of anaphylaxis using nationwide data in Taiwan, 2001-2013

Background

Anaphylaxis is a severe, potentially fatal, and systemic allergic reaction. Previous studies document increasing trends in incidence rates of anaphylaxis-related events in Western countries, yet little is known about the incidence and trend of anaphylaxis in Asia. In this study, we aimed to determine time trends in incidence rates of anaphylaxis-related events in Taiwan from 2001 through 2013.

Methods

We utilized medical claims data from the National Health Insurance Research Databases in Taiwan. We identified anaphylaxis-related events (ICD-9-CM-codes: 995.0, 995.60–995.69, 999.41–999.42, and 999.49) and calculated incidence rates. Poisson regression models were applied to examine trends and incidence rates.

Results

A total of 2496 patients (mean age, 45.11 years; 56% male) with first-time anaphylaxis were identified during 34,430,000 person-years of observation time. The overall incidence of anaphylaxis was 7.25 (95% confidence interval (CI) = 6.97–7.53) per 100,000 person-years, increasing from 4.79 in 2001 to 8.20 in 2013, with an incidence rate ratio (IRR) of 1.05 (95%CI = 1.04–1.06). Over the 13-year period, the increasing trends were found in incident diagnosis of anaphylaxis-related outpatient or emergency department visits (IRR = 1.06, 95%CI = 1.05–1.08) and admissions to intensive care units (IRR = 1.06, 95%CI = 1.03–1.10), whereas the trends in incidence of anaphylaxis-related hospitalizations remained steady. The proportion of patients requiring hospitalizations among all patients with anaphylaxis (p_{_trend} = 0.01), as well as the proportion requiring intensive care treatment among patients who were hospitalized (p_{_trend} = 0.01), both increased with age.

Conclusion

The incidence rate of anaphylaxis in Taiwan has increased at an average rate of 5% annually since 2001, paralleling the rising trends in several Western countries.

Electronic supplementary material

The online version of this article (10.1186/s40413-018-0202-7) contains supplementary material, which is available to authorized users.

Drug-Induced Anaphylaxis

Drugs are among the main triggers of anaphylaxis, but identification of the culprit drug is frequently difficult. To confirm diagnosis of the causative agent, medical records and clinical history are fundamental. There are a few in vitro tests available in clinical practice, such as serum-specific IgE and basophil activation test. Skin tests are often useful for the diagnosis, although drug challenge is indicated in patients with inconclusive clinical history or to provide safe alternatives. Treatment of anaphylaxis is standard and intramuscular epinephrine is the main agent to prevent morbidity and mortality. Rapid desensitization may be indicated in selected cases.

Death by food

Although death from food is not an uncommon finding in forensic facilities worldwide, the range of underlying lethal mechanisms and associated conditions that should be sought at the time of autopsy is quite disparate. Deaths may occur from i) infectious agents including bacteria, viruses, protozoa, cestodes, nematodes and prions; ii) natural toxins including amanita toxins, tetrodotoxin, ciguatera and scombroid; iii) anaphylaxis; iv) poisoning; v) mechanical issues around airway and gut obstruction and/or perforation; and vi) miscellaneous causes. Food-related deaths are important in terms of global mortality, and thus autopsies need to be comprehensive with full ancillary testing. Medicolegal matters may involve issues concerning likely exposure to infectious agents, possible foods ingested, the declared content and possible components of food, the significance of toxicological analyses, and aspects of duty of care in cases of café coronary syndrome and gastroenteritis while in care.

‘Because it kind of falls in between, doesn’t it? Like an acute thing and a chronic’: The psychological experience of anaphylaxis in adulthood

Anaphylaxis is a serious, rare condition increasing in prevalence. This study explored the psychological experience of adult-onset anaphylaxis from patient, family and staff perspectives. Semi-structured interviews were conducted with 12 participants. Two global themes emerged from thematic analysis: ‘controllability’ (‘an unknown and distressing experience’, ‘the importance of control over triggers’ and ‘responsibility but no control: the impact on others’) and ‘conflict’ (‘rejecting illness identity’, ‘minimisation of risk’, ‘accessing specialist care: running in slow motion’ and ‘patient-centred versus service-centred care’). Findings highlight the importance of perceived control and emphasise the presence of conflict in the experience of this complex, episodic condition.

Epidemiology of anaphylaxis

Knowledge about the epidemiology of anaphylaxis is based on data from various sources: clinical practice, large secondary clinical and administrative databases of primary care or hospitalized patients, and recent surveys with representative samples of the general population. As several similar results are often reported in several publications and populations, such findings are highly like to be robust. One such finding is that the incidence and prevalence of anaphylaxis are higher than previously thought. Publications from the last 5 years reveal an incidence of between 50 and 112 episodes per 100 000 person-years; estimated prevalence is 0.3-5.1% depending on the rigour of the definitions used. Figures are higher in children, especially those aged 0-4 years. Publications from various geographical areas based on clinical and administrative data on hospitalized patients suggest that the frequency of admissions due to anaphylaxis has increased (5-7-fold in the last 10-15 years). Other publications point to a geographic gradient in the incidence of anaphylaxis, with higher frequencies recorded in areas with few hours of sunlight. However, these trends could be the result of factors other than a real change in the incidence of anaphylaxis, such as changes in disease coding and in the care provided. Based on data from the records of voluntary declarations of death by physicians and from large national databases, death from anaphylaxis remains very infrequent and stands at 0.35-1.06 deaths per million people per year, with no increases observed in the last 10-15 years. Although anaphylaxis can be fatal, recurrence of anaphylaxis--especially that associated with atopic diseases and hymenoptera stings--affects 26.5-54% of patients.

Optimal treatment of anaphylaxis: antihistamines versus epinephrine

Anaphylaxis is a rapid, systemic, often unanticipated, and potentially life-threatening immune reaction occurring after exposure to certain foreign substances. The main immunologic triggers include food, insect venom, and medications. Multiple immunologic pathways underlie anaphylaxis, but most involve immune activation and release of immunomodulators. Anaphylaxis can be difficult to recognize clinically, making differential diagnosis key. The incidence of anaphylaxis has at least doubled during the past few decades, and in the United States alone, an estimated 1500 fatalities are attributed to anaphylaxis annually. The increasing incidence and potentially life-threatening nature of anaphylaxis coupled with diagnostic challenges make appropriate and timely treatment critical. Epinephrine is universally recommended as the first-line therapy for anaphylaxis, and early treatment is critical to prevent a potentially fatal outcome. Despite the evidence and guideline recommendations supporting its use for anaphylaxis, epinephrine remains underused. Data indicate that antihistamines are more commonly used to treat patients with anaphylaxis. Although histamine is involved in anaphylaxis, treatment with antihistamines does not relieve or prevent all of the pathophysiological symptoms of anaphylaxis, including the more serious complications such as airway obstruction, hypotension, and shock. Additionally, antihistamines do not act as rapidly as epinephrine; maximal plasma concentrations are reached between 1 and 3 hours for antihistamines compared with < 10 minutes for intramuscular epinephrine injection. This demonstrates the need for improved approaches to educate physicians and patients regarding the appropriate treatment of anaphylaxis.

Demonstration of epinephrine autoinjectors (EpiPen and Anapen) by pharmacists in a randomised, simulated patient assessment: acceptable, but room for improvement

BACKGROUND

Successful treatment of anaphylaxis in the community relies on early and correct use of epinephrine autoinjectors. Community pharmacists supply these devices and have a crucial role teaching patients how to use them. Supply of epinephrine autoinjectors in Australia increased 70-fold in the past decade. New EpiPen and Anapen autoinjectors were launched in Australia in 2011 and 2012, with the potential to cause confusion. However there is no information about how pharmacists demonstrate epinephrine autoinjectors to patients. Therefore the aim of this study was to assess real-world community pharmacist demonstrations of EpiPen and Anapen. We also sought to identify consultation-based predictors of accurate demonstration.

METHODS

Demonstration accuracy was assessed in simulated patient visits to 300 randomly selected pharmacies. Pharmacists were asked by the simulated patient how to use original EpiPen, new-look EpiPen or Anapen, and assessed against the relevant Australasian Society of Clinical Immunology and Allergy (ASCIA) Action Plan for Anaphylaxis. Other anaphylaxis advice provided by the pharmacist was also recorded. Accuracy was analysed descriptively. Binary logistic regression was used to identify predictors of accurate demonstration.

RESULTS

All 300 pharmacies were visited. Of 250 pharmacist demonstrations, 46 (18.4%) accurately demonstrated all four steps on ASCIA Action Plan. Failure to state 'do not touch the needle' (74.8%) or 'massage injection site' (68.8%) reduced accuracy. However 163 (65.2%) accurately demonstrated the three steps required to inject epinephrine (no difference by device, p = 0.15). Associations with accurate demonstration were: checking if the patient had an anaphylaxis action plan (odds ratio, OR = 16.1; 95% CI: 3.86-67.3); stating to call an ambulance after use (OR = 4.0; 95% CI: 1.44-11.1); or explaining side effects of epinephrine (OR = 4.5; 95% CI: 1.48-13.4).

CONCLUSIONS

It is critical that anaphylaxis patients know how to use their prescribed epinephrine autoinjector correctly. Pharmacists have acceptable rates of EpiPen and Anapen demonstration accuracy, although more is needed to improve this. Those who pay attention to the need for action plans, emergency care after epinephrine use, and informing patients about the side effects of epinephrine may have better knowledge about anaphylaxis, and in turn significantly improve demonstration accuracy.

Long-term effectiveness of online anaphylaxis education for pharmacists

OBJECTIVE

To evaluate the long-term effectiveness of an Australasian Society of Clinical Immunology and Allergy (ASCIA) anaphylaxis e-learning program compared to lectures or no training.

DESIGN

A controlled interrupted-time-series study of Australian pharmacists and pharmacy students who completed ASCIA anaphylaxis e-learning or lecture programs was conducted during 2011-2013. Effectiveness was measured using a validated test administered pretraining, posttraining, and 3 and 7 months after training.

ASSESSMENT

All learning groups performed significantly better on all posttests compared to the pretest, and compared to a control group (p<0.001). The proportion of e-learners achieving the minimum standard for anaphylaxis knowledge improved from 45% at pretest to 87% at 7 months.

CONCLUSION

The ASCIA e-learning program significantly increased anaphylaxis knowledge. The high proportion of participants achieving the minimum standard at 7 months indicates long-term knowledge change.

Predictors of the severity and serious outcomes of anaphylaxis in korean adults: a multicenter retrospective case study

Purpose

Differences in definitions of the condition, relevant triggers, and the geographical locations of study centers, cause estimates of the prevalence of anaphylaxis to vary. Recent epidemiological data indicate that the incidence of anaphylaxis is rising.

Methods

To investigate the causes and clinical features of anaphylaxis in Korean adults, factors associated with the severity of the condition, and serious outcomes, a retrospective medical record review was performed on adult patients diagnosed with anaphylaxis between 2007 and 2011 in 15 University Hospitals of South Korea.

Results

A total of 1,806 cases (52% male, age 16-86 years) were reported. Cutaneous symptoms (84.0%), combined with respiratory (53.9%) and/or cardiovascular (55.4%) symptoms, were the most frequent presentations. Using a recognized grading system, 1,776 cases could be classified as either mild, 340; moderate, 690; or severe, 746. Although eliciting factors varied significantly by age, gender, and regional and seasonal factors, drugs (46.5%; including nonsteroidal anti-inflammatory drugs, antibiotics, and radiocontrast media) were the most common cause of anaphylaxis, followed by foods (24.2%), insect stings (16.4%), exercise (5.9%), and unknown etiology (7.0%). All of age, multi-organ involvement, a history of allergic disease, and drug-induced anaphylaxis, were significant predictors of serious outcomes requiring hospital admission or prolongation of hospital stay. Epinephrine auto-injectors were prescribed for 7.4% of reported cases.

Conclusions

The principal causes of anaphylaxis in Korean adults were drugs, food, and insect stings. Drug-associated anaphylaxis, a history of allergic disease, multi-organ involvement, and older age, were identified as predictors of serious outcomes.

Risk factors for severe anaphylaxis in patients receiving anaphylaxis treatment in US emergency departments and hospitals

BACKGROUND

Although reported risk factors for severe anaphylaxis include older age, presence of comorbid medical conditions, and concomitant medications, previous studies have used varying definitions for anaphylaxis and heterogeneous methodology.

OBJECTIVE

To describe risk factors for severe anaphylaxis among US patients treated in emergency departments (EDs) or hospitals for anaphylaxis.

METHODS

Individuals with an ED visit/hospitalization for anaphylaxis were identified from 2 MarketScan Research Databases using an expanded International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm. Eligibility for the current study required continuous medical and prescription coverage for at least 1 year before and after the index date. Severe anaphylaxis was defined as a reaction requiring hospital admission.

RESULTS

Among 11,972 individuals, 2,622 (22%) had severe anaphylaxis. Unadjusted analysis showed that severe anaphylaxis was associated with older age and higher comorbidity burden. These patients were also less likely to have filled an epinephrine autoinjector (EAI) prescription or visited an allergist/immunologist, but more likely to have had an ED visit/hospitalization (any cause). On multivariable analysis, filling an EAI prescription (odds ratio [OR], 0.64; 95% CI, 0.53-0.78) or visiting an allergist/immunologist (OR, 0.78; 95% CI, 0.63-0.95) before the index event was associated with a lower risk of severe anaphylaxis, while any previous ED visit (OR, 1.18; 95% CI, 1.07-1.30) or hospitalization (OR, 1.55; 95% CI, 1.36-1.75) was associated with a higher risk of severe anaphylaxis.

CONCLUSIONS

In this large cohort with an ED visit or hospitalization for anaphylaxis, 22% had severe anaphylaxis. Pre-index preventive anaphylaxis care (ie, EAI prescription fill and allergist/immunologist visit) was associated with a significantly lower risk, supporting the benefits of preventive anaphylaxis care in real-world practice.

Case fatality and population mortality associated with anaphylaxis in the United States

BACKGROUND

Anaphylaxis is a serious allergic reaction that can cause death; however, the actual risk of death is unclear.

OBJECTIVE

We sought to estimate the case fatality rate among hospitalizations or emergency department (ED) presentations for anaphylaxis and the mortality rate associated with anaphylaxis for the general population.

METHODS

This was a population-based epidemiologic study using 3 national databases: the Nationwide Inpatient Sample (NIS; 1999-2009), the Nationwide Emergency Department Sample (NEDS; 2006-2009), and Multiple Cause of Death Data (MCDD; 1999-2009). Sources for these databases are hospital and ED discharge records and death certificates, respectively.

RESULTS

Case fatality rates were between 0.25% and 0.33% among hospitalizations or ED presentations with anaphylaxis as the principal diagnosis (NIS+NEDS, 2006-2009). These rates represent 63 to 99 deaths per year in the United States, approximately 77% of which occurred in hospitalized patients. The rate of anaphylaxis-related hospitalizations increased from 21.0 to 25.1 per million population between 1999 and 2009 (annual percentage change, 2.23%; 95% CI, 1.52% to 2.94%), contrasting with a decreasing case fatality rate among hospitalizations (annual percentage change, -2.35%; 95% CI, -4.98% to 0.34%). Overall mortality rates ranged from 0.63 to 0.76 per million population (186-225 deaths per year, MCDD) and appeared stable in the last decade (annual percentage change, -0.31%; 95% CI, -1.54% to 0.93%).

CONCLUSION

From 2006 to 2009, the overwhelming majority of hospitalizations or ED presentations for anaphylaxis did not result in death, with an average case fatality rate of 0.3%. Anaphylaxis-related hospitalizations increased steadily in the last decade (1999-2009), but this increase was offset by the decreasing case fatality rate among those hospitalized; both inpatient and overall mortality rates associated with anaphylaxis appeared stable and were well under 1 per million population. Although anaphylactic reactions are potentially life-threatening, the probability of dying is actually very low. With the prevalence of anaphylaxis on the increase, practitioners need to stay vigilant and follow the treatment guidelines to further reduce anaphylaxis-related deaths.

Combined effects of food and exercise on anaphylaxis

Food-dependent exercise-induced anaphylaxis (FDEIAn) is induced by different types and various intensities of physical activity, and is distinct from food allergies. It has been shown that consumption of allergenic food followed by exercise causes FDEIAn symptoms. Intake of allergenic food or medication before exercise is a major predisposing factor for FDEIAn. Urticaria and severe allergic reactions are general symptoms of FDEIAn. Dermatological tests and serum IgE assays are the typical prescreening methods, and have been used for several decades. However, these screening tests are not sufficient for detecting or preventing FDEIAn. It has been found that exercise may stimulate the release of mediators from IgE-dependent mast cells that can result in FDEIAn when a certain threshold level has been exceeded. Mast cell degradation might be a major factor to induce FDEIAn but this has not been determined. A number of foods have been reported to be involved in the onset of FDEIAn including wheat, eggs, chicken, shrimp, shellfish, nuts, fruits, and vegetables. It is also known that aspirin increases the occurrence of type I allergy symptoms when combined with specific foods. Moreover, high intensity and frequent exercise are more likely to provoke an attack than low intensity and less frequent exercise. In this paper, we present the current views of the pathophysiological mechanisms underlying FDEIAn within the context of exercise immunology. We also present a detailed FDEIAn definition along with etiologic factors and medical treatment for cholinergic urticaria (UC) and exercise-induced anaphylaxis (EIA).

Progress in understanding the epigenetic basis for immune development, immune function, and the rising incidence of allergic disease

The profile of allergic disease worldwide continues to change as the number of severe IgE-mediated allergies increases. This phenomenon is thought to reflect the outcome of combined genetic/environmental/developmental/stochastic effects on immune development, but understanding this remains a challenge. Epigenetic disruption at key immune genes during development has been proposed as a potential explanation for how environmental exposures may alter immune cell development and function. This represents an emerging area of research with the potential to yield new understanding of how disease risk is modified. Here, we examine recent developments in this field that are defining new epigenetic paradigms of allergic disease.

IgE-Mediated Anaphylaxis to Foods, Venom, and Drugs: Influence of Serum Angiotensin Converting Enzyme Levels and Genotype

Circulating angiotensin-II protects the circulation against sudden falls in blood pressure and is generated by the enzymatic action of angiotensin converting enzyme (ACE) on angiotensin-I. The ACE genes have 2 allelic forms, “I” and “D.” The “D” genotype has both highest angiotensin-II generation and serum ACE levels compared to “I”. 120 patients with IgE-anaphylaxis, 119 healthy controls, and 49 atopics had serum ACE levels, ACE genotype, and renin levels determined. Plasma renin levels were identical for all groups. Serum ACE levels and genotypes were similar for healthy controls (HC) and atopics, but lower in anaphylaxis (P = 0.012), with ACE genotypes also showing increased “I” genes (P = 0.009). This effect was more pronounced in subjects manifesting airway angioedema and cardiovascular collapse (AACVS) than mild cutaneous and respiratory (CRA) symptoms. AACVS was significantly associated with the presence of “I” genes. For “ID” genotype OR is 5.6, 95% CI 1.8 to 17.4, and for “II” genotype OR is 44, 95% CI 5 to 1891 within the anaphylaxis group = 0.001. The results show a difference in the genotype frequency between control and anaphylaxis, suggesting a role for the renin angiotensin system in anaphylaxis manifesting with airway angioedema and cardiovascular collapse.

Anaphylaxis in Latin American children and adolescents: the Online Latin American Survey on Anaphylaxis (OLASA)

OBJECTIVES

To identify the main clinical manifestations, triggers, and treatment of severe allergic reactions (SAR) in children and adolescents (n=191, up to 18 years of age) seen by allergologists and registered in the Online Latin American Survey of Anaphylaxis (OLASA).

RESULTS

53.0% of the patients were males and the aetiological agent was identified in 85.5% of them as follows: foods (36.1%), drugs (27.7%), and insect stings (26.2%). The most common symptoms during an acute episode were cutaneous (94.2%), and respiratory (78.5%). Most patients were treated in emergency setting, yet only 34.6% received parenteral epinephrine and 14.3% had to be hospitalised.

CONCLUSION

Cutaneous symptoms ranked the order of clinical presentation of SAR. Food was the main triggering agent in the younger cases and insect sting and drugs in the adolescents. Treatment provided for SAR was not appropriate. It is necessary to improve educational programmes in order to enhance the knowledge on this potentially fatal emergency.

Harmonization process for the identification of medical events in eight European healthcare databases: the experience from the EU-ADR project

OBJECTIVE

Data from electronic healthcare records (EHR) can be used to monitor drug safety, but in order to compare and pool data from different EHR databases, the extraction of potential adverse events must be harmonized. In this paper, we describe the procedure used for harmonizing the extraction from eight European EHR databases of five events of interest deemed to be important in pharmacovigilance: acute myocardial infarction (AMI); acute renal failure (ARF); anaphylactic shock (AS); bullous eruption (BE); and rhabdomyolysis (RHABD).

DESIGN

The participating databases comprise general practitioners' medical records and claims for hospitalization and other healthcare services. Clinical information is collected using four different disease terminologies and free text in two different languages. The Unified Medical Language System was used to identify concepts and corresponding codes in each terminology. A common database model was used to share and pool data and verify the semantic basis of the event extraction queries. Feedback from the database holders was obtained at various stages to refine the extraction queries.

MEASUREMENTS

Standardized and age specific incidence rates (IRs) were calculated to facilitate benchmarking and harmonization of event data extraction across the databases. This was an iterative process.

RESULTS

The study population comprised overall 19 647 445 individuals with a follow-up of 59 929 690 person-years (PYs). Age adjusted IRs for the five events of interest across the databases were as follows: (1) AMI: 60-148/100 000 PYs; (2) ARF: 3-49/100 000 PYs; (3) AS: 2-12/100 000 PYs; (4) BE: 2-17/100 000 PYs; and (5) RHABD: 0.1-8/100 000 PYs.

CONCLUSIONS

The iterative harmonization process enabled a more homogeneous identification of events across differently structured databases using different coding based algorithms. This workflow can facilitate transparent and reproducible event extractions and understanding of differences between databases.

Undernotification of anaphylaxis deaths in Brazil due to difficult coding under the ICD-10

BACKGROUND

Undernotification is well recognized as a key challenge to the study of anaphylaxis mortality, but it is seldom mentioned that one of its reasons is the difficult coding of the condition under the tenth revision of the international classification of diseases (ICD-10), given that there are no anaphylaxis-specific ICD-10, which are considered valid for coding underlying causes-of-death, and that official mortality statistics consider exclusively the underlying and disregard the contributing causes-of-death data recorded on death certificates. Brazilian mortality data were used as a case study to call attention to the inadequacy of the ICD-10 for the measurement of anaphylaxis deaths.

METHODS

Underlying and contributing causes-of-death data were used to estimate the rates of anaphylaxis deaths in the country over the years 2008-2010.

RESULTS

Of 498 anaphylaxis deaths were found, of which 75% were classified as 'definite' and 25% as 'possible anaphylaxis deaths'. The average national rate for these years was 0.87 per million per year. None of these deaths would have been found had we exclusively considered information from the underlying cause-of-death field.

CONCLUSION/RECOMMENDATIONS

The study of anaphylaxis mortality using secondary data requires the use of information derived from the underlying as well as from the contributing causes-of-death fields. Coding definitions should be standardized with a view of enabling trend analyses and international comparisons. The ICD-11 revision is a unique opportunity to improve the coding system so as to facilitate epidemiological studies of anaphylaxis mortality. Educational interventions targeted at improving the quality of death certificate completion are urgently needed.

Severe ranitidine-induced anaphylaxis: a case report and literature review

WHAT IS KNOWN AND OBJECTIVE

Ranitidine is a generally well-tolerated drug, and serious side effects are rare. However, ranitidine-induced anaphylaxis has been reported on rare occasions. We report on such a case and review other cases reported in the literature.

CASE SUMMARY

A 36-year-old man with no history of other medications, illnesses or allergic diseases, especially to drugs, consulted our emergency department because of renal colic and epigastric discomfort. He was given 50 mg of ranitidine as a slow intravenous bolus and 20 mg of piroxicam intramuscularly. Within the first minute, the patient developed a cold sweat, trembling, dyspnoea and deterioration of his consciousness. The condition was considered as an anaphylactic shock, and cardiopulmonary resuscitation and inotropic support were immediately commenced. Two days later, he was weaned off the ventilator as he was haemodynamically stable. He was discharged after 7 days. Four weeks later, skin prick tests to ranitidine and piroxicam were performed on the forearm of the patient. He reacted strongly to ranitidine about 10 min later but not to piroxicam. To assess cross-reactivity to other H2- and H1-receptor antagonists in our patient, we subsequently performed prick tests to famotidine, cimetidine and desloratadine and all were negative.

WHAT IS NEW AND CONCLUSION

We re-emphasize a potentially serious, albeit very rare, adverse effect of ranitidine and summarize other reported cases. This case demonstrates that commonly used, generally safe drugs may on occasions cause serious adverse effects.

Epidemiology and risk factors for drug allergy

The aim of this review was to describe the current evidence-based knowledge of the epidemiology, prevalence, incidence, risk factors and genetic associations of drug allergy. Articles published between 1966 and 2010 were identified in MEDLINE using the key words adult, adverse drug reaction reporting systems, age factors, anaphylactoid, anaphylaxis, anaesthetics, antibiotics, child, drug allergy, drug eruptions, ethnic groups, hypersensitivity, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, sex factors, Stevens Johnson syndrome and toxic epidermal necrolysis. Additional studies were identified from article reference lists. Relevant, peer-reviewed original research articles, case series and reviews were considered for review. Current epidemiological studies on adverse drug reactions (ADRs) have used different definitions for ADR-related terminology, often do not differentiate immunologically and non-immunologically mediated drug hypersensitivity, study different study populations (different ethnicities, inpatients or outpatients, adults or children), utilize different methodologies (spontaneous vs. non-spontaneous reporting, cohort vs. case-control studies), different methods of assessing drug imputability and different methods of data analyses. Potentially life-threatening severe cutaneous adverse reactions (SCAR) are associated with a high risk of morbidity and mortality. HLA associations for SCAR associated with allopurinol, carbamazepine and abacavir have been reported with the potential for clinical use in screening prior to prescription. Identification of risk factors for drug allergy and appropriate genetic screening of at-risk ethnic groups may improve the outcomes of drug-specific SCAR. Research and collaboration are necessary for the generation of clinically-relevant, translational pharmacoepidemiological and pharmacogenomic knowledge, and success of health outcomes research and policies on drug allergies.

Exercise-induced anaphylaxis: an update on diagnosis and treatment

Exercise-induced anaphylaxis (EIA) and food-dependent, exercise-induced anaphylaxis (FDEIA) are rare but potentially life-threatening clinical syndromes in which association with exercise is crucial. The range of triggering physical activities is broad, including as mild an effort as a stroll. EIA is not fully repeatable (ie, the same exercise may not always result in anaphylaxis in a given patient). In FDEIA, the combined ingestion of sensitizing food and exercise is necessary to precipitate symptoms. Clinical features and management do not differ significantly from other types of anaphylaxis. The pathophysiology of EIA and FDEIA is not fully understood. Different hypotheses concerning the possible influence of exercise on the development of anaphylactic symptoms are taken into consideration. These include increased gastrointestinal permeability, blood flow redistribution, and most likely increased osmolality. This article also describes current diagnostic and therapeutic possibilities, including changes in lifestyle and preventive properties of antiallergic drugs as well as acute treatment of these dangerous syndromes.

The HealthNuts population-based study of paediatric food allergy: validity, safety and acceptability

BACKGROUND

The incidence of hospital admissions for food allergy-related anaphylaxis in Australia has increased, in line with world-wide trends. However, a valid measure of food allergy prevalence and risk factor data from a population-based study is still lacking.

OBJECTIVE

To describe the study design and methods used to recruit infants from a population for skin prick testing and oral food challenges, and the use of preliminary data to investigate the extent to which the study sample is representative of the target population.

METHODS

The study sampling frame design comprises 12-month-old infants presenting for routine scheduled vaccination at immunization clinics in Melbourne, Australia. We compared demographic features of participating families to population summary statistics from the Victorian Perinatal census database, and administered a survey to those non-responders who chose not to participate in the study.

RESULTS

Study design proved acceptable to the community with good uptake (response rate 73.4%), with 2171 participants recruited. Demographic information on the study population mirrored the Victorian population with most the population parameters measured falling within our confidence intervals (CI). Use of a non-responder questionnaire revealed that a higher proportion of infants who declined to participate (non-responders) were already eating and tolerating peanuts, than those agreeing to participate (54.4%; 95% CI 50.8, 58.0 vs. 27.4%; 95% CI 25.5, 29.3 among participants).

CONCLUSION

A high proportion of individuals approached in a community setting participated in a food allergy study. The study population differed from the eligible sample in relation to family history of allergy and prior consumption and peanut tolerance, providing some insights into the internal validity of the sample. The study exhibited external validity on general demographics to all births in Victoria.

Anaphylaxis in Latin America: a report of the online Latin American survey on anaphylaxis (OLASA)

OBJECTIVES

The aims of the Online Latin American Survey of Anaphylaxis (OLASA) were to identify the main clinical manifestations, triggers, and treatments of severe allergic reactions in patients who were seen by allergists from July 2008 to June 2010 in 15 Latin American countries and Portugal (n =634).

RESULTS

Of all patients, 68.5% were older than 18 years, 41.6% were male, and 65.4% experienced the allergic reaction at home. The etiologic agent was identified in 87.4% of cases and predominantly consisted of drugs (31.2%), foods (23.3%), and insect stings (14.9%). The main symptom categories observed during the acute episodes were cutaneous (94.0%) and respiratory (79.0%). The majority of patients (71.6%) were treated initially by a physician (office/emergency room) within the first hour after the reaction occurred (60.2%), and 43.5% recovered in the first hour after treatment. Most patients were treated in an emergency setting, but only 37.3% received parenteral epinephrine alone or associated with other medication. However, 80.5% and 70.2% were treated with corticosteroids or antihistamines (alone or in association), respectively. A total of 12.9% of the patients underwent reanimation maneuvers, and 15.2% were hospitalized. Only 5.8% of the patients returned to the emergency room after discharge, with 21.7% returning in the first 6 hours after initial treatment.

CONCLUSION

The main clinical manifestations of severe allergic reactions were cutaneous. The etiologic agents that were identified as causing these acute episodes differed according to age group. Following in order: drugs (31.2%), foods (23.3% and insect stings (14.9%) in adults with foods predominance in children. Treatment provided for acute anaphylactic reactions was not appropriate. It is necessary to improve educational programs in order to enhance the knowledge on this potentially fatal emergency.

Anaphylaxis and insect allergy

PURPOSE OF REVIEW

Anaphylaxis is an acute-onset and potentially life-threatening allergic reaction that can be caused by numerous allergic triggers including stinging insects. This review focuses on recent advances, natural history, risk factors and therapeutic considerations.

RECENT FINDINGS

Recent work suggests that concerns over insect allergy diagnosis continue to exist. This is especially true with individuals who have a convincing history of a serious life-threatening anaphylactic event, but lack the necessary diagnostic criteria of venom-specific IgE by skin test or in-vitro diagnostic methods to confirm the diagnosis. The role of occult mastocytosis or increased basophile reactivity may play a role in this subset population. Additionally, epinephrine continues to be underutilized as the primary acute intervention for an anaphylactic reaction in the emergent setting.

SUMMARY

The incidence of anaphylaxis continues to rise across all demographic groups, especially those less than 20 years of age. Fortunately, the fatalities related to anaphylaxis appear to have decreased over the past decades. Our understanding of various triggers, associated risk factors, as well as an improved understanding and utilization of biological markers such as serum tryptase have improved. Our ability to treat insect anaphylaxis by venom immunotherapy is highly effective. Unfortunately, anaphylaxis continues to be underappreciated and undertreated especially in regard to insect sting anaphylaxis. This includes the appropriate use of injectable epinephrine as the primary acute management tool. These findings suggest that continued education of the general population, primary care healthcare providers and emergency departments is required.