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

Evidence-based data support strategies for the prevention of Hymenoptera venom anaphylaxis

PURPOSE OF REVIEW

This review aims to identify phenotypes at-risk of Hymenoptera venom-induced anaphylaxis (HVA), focusing on different perspectives (epidemiological, clinical, and therapeutic) in order to adapt future preventive strategies.

RECENT FINDINGS

HVA remains one of the leading causes of anaphylaxis, with a broad pattern of symptoms. Although most cases occur outside healthcare settings, data indicate a high emergency admission rate due to insect stings. Mortality is often underestimated because of the lack of witnesses and difficulties in recognizing the signs and the culprit. Targeting risk factors could be a clue to improve these statistics and the prognosis of the disease.Potential risk factors for severe HVA in the European population are basal serum tryptase (BST) above 8 μg, mast cell disorders, the absence of skin symptoms, and cardiovascular conditions requiring the use of beta blockers and ACE inhibitors. Identifying these criteria, mainly based on clinical patterns, helps to develop personalized strategies for management and prevention.

SUMMARY

With a personalized medicine approach, phenotypes must be characterized to adapt to the management of patients suffering from Hymenoptera venom anaphylaxis (HVA), including venom immunotherapy (VIT). In this systematic review, all articles mentioned systemic reactions with heterogeneous severity degrees. Half of those reported grade III-IV systemic reactions (Ring and Messmer). HVA clinical patterns could be worsened by one Hymenoptera sting, a patient's history with mast cell disorders, or cardiovascular diseases. VIT failure was attributed to bee venom extract and monotherapy in two-thirds of publications. Findings stress the difficulty of having uniform epidemiological data on HVA and the lack of financial support in some world regions to support appropriate management of these conditions. Although observing a heterogeneity of data, we were able to identify potential risk factors, in particular for the severe cases. We believe our work will support allergists and health professionals to implement improved personalized management of patients suffering from severe HVA.

Who is at-risk for severe anaphylaxis in France?

Background

The understanding of risk factors related to severe anaphylaxis is key to implementing prevention strategies. We present the first French population-based nine-year anaphylaxis hospitalization study evaluating specific trends and factors related to severe anaphylaxis (SA), to support identification of phenotypes at-risk.

Methods

This study used descriptive data from the French hospitalization database for the years 2012-2021, and included all patients hospitalized with anaphylaxis using International Classification of Diseases (ICD)-10 codes listed as a primary diagnosis. SA were cases that either required a hospitalization in intensive care units or resulted in death. Potential risk factors were identified according to corresponding ICD codes, available as secondary data during the patient's hospitalization.

Results

The average hospitalization rate of all cases of anaphylaxis (SA and non-SA) was 1.34/100,000/year, and rate of admissions for SA was 0.08/100,000/year. Among the 5463 SA, 37.7% had unspecified coding label, when trigger was not identified. For SA cases in which trigger was identified, most were related to drugs (45.6%), followed by food (9.3%) and insect sting (7.2%). Overall, admissions due to anaphylaxis (SA and non-SA) were more frequent in males (57%). However, when the trigger was drugs, the proportion was significantly higher in females. For children aged 5-9 years, the most common trigger for SA was food. Patients for which SA was triggered by insect stings were identified exclusively in the 10-14 years age group. Chronic spontaneous urticaria was associated with insect sting-induced anaphylaxis, regardless of the severity. Angioedema was associated with all causes of SA. Cases of anaphylaxis presenting with urticaria and angioedema included cases with identified and unidentified triggers. Asthma and a personal history of allergy were associated with drug- and food-induced anaphylaxis.

Conclusion

This is the first study to provide data on severe phenotypes of anaphylaxis in France. Data presented is key to the implementation of public health actions and preventive strategies to improve quality care.

Allergic and hypersensitivity condition in the International Patients' Summary (IPS) standard: The need of updates through the International Classification of Diseases (ICD)-11

In 2010, the United States Human and Health Services (US HHS) and the European Union's (EU) Directorate General for Communications Networks, Content and Technology signed a memorandum of understanding to stimulate cooperation surrounding health-related information communications technology. The key project that emerged from this agreement is the International Patient Summary (IPS), intended to provide succinct clinically relevant patient summaries, which are generalizable and condition-independent, that can be readily used by all clinicians for the care of patients. Although allergies are included in the main information required by the IPS library and framework, it is misrepresented which leads to underdiagnosis or misdiagnosis of patients suffering from allergic and hypersensitivity conditions (A/H). The French and Montpellier World Health Organization (WHO) Collaborating Centres have provided arguments for supporting representation of A/H in the IPS. These are based on the relevance of the new classification of A/H in the WHO International Classification of Diseases 11th version (ICD-11), and the need for alignment of eHealth tools with harmonized health information. We first present the A/H in the IPS initiative with the mission of producing an international information system that can be used globally in electronic health records to standardize clinical diagnoses and facilitate communication between clinicians caring for patients with A/H diseases. It is believed this initiative will provide a strong voice for the allergy community and an effective process for improving the quality of health data that will optimize medical care for our patients worldwide.

Drug allergy awareness and perspectives with the implementation of the International Classification of Diseases-11

PURPOSE OF REVIEW

To understand the current global scale of drug hypersensitivity (DH) and drug allergy (DA), and to identify possible strategies to increase the accuracy of epidemiological data.

RECENT FINDINGS

Global patterns of DH/DA seem to be changing and increasing worldwide, but there are still great challenges in capturing quality DH/DA mortality and morbidity statistics (MMS). DH/DA MMS may gain new perspectives with the global implementation of the International Classification of Diseases (ICD)-11. Improving the quality of epidemiological data related to DH/DA should clarify areas of uncertainty, which would lead to better strategies to reduce the burden of these conditions.

SUMMARY

DH/DA remains a complex and unaddressed problem globally that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. DH/DA labels should contribute to people well being, by protecting true allergic individuals from being re-exposed to their allergic drugs and providing needed medications to individuals wrongly labeled as allergic or who have lost allergic sensitivity. The true rate of DH/DA is in fact unknown due to a number of factors, such as misdiagnosis, miscoding and under- and over-notification, among others. Moreover, there is lack of data about DH/DA epidemiology in many countries. Difficulties on collecting accurate and comparable data should be acknowledged, with great impact in the correct labeling DH/DA in electronic health records and official statistics. More accurate definitions, classification and coding may contribute to a better-quality MMS thanks to the ICD-11, under implementation worldwide. Improving the quality of epidemiological data related to DH/DA should clarify areas of uncertainty, which would lead to better strategies to reduce the burden of these conditions. As knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to DH/DA in the ICD-11 will allow the collection of more accurate epidemiological data to support quality management of patients, and facilitate healthcare planning to implement public health measures to prevent and reduce the morbidity and mortality attributable to these conditions.

Fatal food anaphylaxis in adults and children

Anaphylaxis is a life-threatening reaction characterized by the acute onset of symptoms involving different organ systems and requiring immediate medical intervention. The incidence of fatal food anaphylaxis is 0.03 to 0.3 million/people/year. Most fatal food-induced anaphylaxis occurs in the second and third decades of life. The identified risk factors include the delayed use of epinephrine, the presence of asthma, the use of recreational drugs (alcohol, nicotine, cannabis, etc.), and an upright position. In the United Kingdom (UK) and Canada, the reported leading causal foods are peanuts and tree nuts. In Italy, milk seems to be the most common cause of fatal anaphylaxis in children < 18 years. Fatal food anaphylaxis in Italian children and adolescents almost always occurs outside and is characterized by cardiorespiratory arrest; auto-injectable adrenaline intramuscular was available in few cases. Mortality from food anaphylaxis, especially in children, is a very rare event with stable incidence, but its risk deeply impacts the quality of life of patients with food allergy and their families. Prevention of fatal food anaphylaxis must involve patients and their families, as well as the general public, public authorities, and patients' associations.

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

Fatal and Near-Fatal Anaphylaxis: Data From the European Anaphylaxis Registry and National Health Statistics

BACKGROUND

Anaphylaxis is a serious systemic reaction-data on fatal and near-fatal reactions are limited.

OBJECTIVE

To better understand clinical patterns and risks factors of severe anaphylaxis by a deep analysis of data from fatal and near-fatal anaphylaxis.

METHODS

Data from the European Anaphylaxis Registry on fatal/near-fatal anaphylactic reactions and national data on anaphylaxis fatalities were investigated.

RESULTS

A total of 305 fatal/near-fatal reactions among children and adults including 35 fatalities from the European Anaphylaxis Registry were identified. The most frequent elicitors were drugs, insects, and food. Male patients (66%/60%) were more frequently affected. Male sex, higher age, concomitant mastocytosis, and cardiovascular disease were associated with a more severe outcome. With increasing reaction severity, skin symptoms were less frequently observed (45% of fatal reactions). In parallel, anaphylaxis mortality rates were studied. The data show that anaphylaxis mortality rates increased in Germany from 0.48 (2009) to 0.59 per 1,000,000 population per year (2020). This increase was apparent only in the female population. In this data set, drugs were the most frequent elicitor of anaphylaxis fatalities, and the rate for this increased over time.

CONCLUSIONS

We identified not only elicitors but also individual factors to be associated with an increased risk of fatal anaphylaxis. Such patients should be recognized and managed with great caution. The increase in drug-induced fatalities points to the need for a better allergological care of patients suffering from drug hypersensitivity.

Global disparities in availability of epinephrine auto-injectors

Background

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions and can cause death. Given the prevalence of anaphylaxis within healthcare systems, it is a high priority public health issue. However, management of anaphylaxis - both acute and preventative - varies by region.

Methods

The World Allergy Organization (WAO) Anaphylaxis Committee and the WAO Junior Members Steering Group undertook a global online survey to evaluate local practice in the diagnosis and management of anaphylaxis across regions.

Results

Responses were received from WAO members in 66 countries. While intramuscular epinephrine (adrenaline) is first-line treatment for anaphylaxis, some countries continue to recommend alternative routes in contrast to guidelines. Epinephrine auto-injector (EAI) devices, prescribed to individuals at ongoing risk of anaphylaxis in the community setting, are only available in 60% of countries surveyed, mainly in high-income countries. Many countries in South America, Africa/Middle-East and Asian-Pacific regions do not have EAI available, or depend on individual importation. In countries where EAIs are commercially available, national policies regarding the availability of EAIs in public settings are limited to few countries (16%). There is no consensus regarding the time patients should be observed following emergency treatment of anaphylaxis.

Conclusion

This survey provides a global snapshot view of the current management of anaphylaxis, and highlights key unmet needs including the global availability of epinephrine for self-injection as a key component of anaphylaxis management.

Epidemiology of anaphylaxis: is the trend still going up?

PURPOSE OF REVIEW

To understand the current global scale of anaphylaxis and identify possible strategies to increase the accuracy of epidemiological data.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics may gain new perspectives with the global implementation of the ICD-11. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate health care planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

The true rate of anaphylaxis is unknown due to a number of factors, such as misdiagnosis, miscoding and undernotification. Moreover, there is lack of information about anaphylaxis epidemiology in many countries. Difficulties on collecting accurate and comparable data should be acknowledged and anaphylaxis data can vary widely. Currently, most robust data are derived from hospitalization datasets and national mortality databases. Anaphylaxis accounts for up to 0.26% of overall hospital admissions. It is suggested that the number of hospital admissions for anaphylaxis is increasing in many countries, both with respect to all-causes of anaphylaxis and by trigger, but the mortality rate remains low. However, there are still great challenges in capturing quality anaphylaxis mortality and morbidity statistics. Better understanding of anaphylaxis trends should clarify some areas of uncertainty about risk factors and prospect effective prevention strategies. As the knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support high quality management of patients, and to better facilitate health care planning to implement public health measures, reduce the morbidity and mortality attributable to anaphylaxis.

Extrinsic and Intrinsic Modulators of Anaphylaxis

The severity of anaphylaxis is determined by many factors. The allergenic source as well as the age of the affected individual and the route of allergen exposure encompass the major contributors of the clinical outcome. Moreover, the severity can be modulated further by intrinsic and extrinsic factors. Among these, the genetic predisposition, certain comorbidities such as uncontrolled asthma, and hormonal fluctuations have been proposed as intrinsic and antihypertensive medications or physical activity as extrinsic factors. Recent advances have highlighted immunologic pathways that may exacerbate the response to allergens through receptors on mast cells, basophils, platelets, and other granulocytes. Atopy, platelet-activating factor acetylhydrolase deficiency, hereditary alpha tryptasemia, and clonal mast cell disorders are examples associated with genetic alterations that may predispose to severe anaphylaxis. Identifying risk factors that lower the threshold of reactivity or increase the severity of multisystem reactions is important in the management of this patient population.

Direct Versus Indirect Query Performance of ICD-9/-10 Coding to Identify Anaphylaxis

BACKGROUND

Anaphylaxis is an often under =diagnosed, severe allergic event for which epidemiological data are sporadic. Researchers have leveraged administrative and claims data algorithms to study large databases of anaphylactic events; however, little longitudinal data analysis is available after transition to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM).

OBJECTIVE

Study longitudinal trends in anaphylaxis incidence using direct and indirect query methods.

METHODS

Emergency department (ED) and inpatient data were analyzed from a large state health care administration database from 2011 to 2020. Incidence was calculated using direct queries of anaphylaxis ICD-9-CM and ICD-10-CM codes and indirect queries using a symptom-based ICD-9-CM algorithm and forward mapped ICD-10-CM version to identify undiagnosed anaphylaxis episodes and to assess algorithm performance at the population level.

RESULTS

An average of 2.4 million inpatient and 7.5 million ED observations/y were analyzed. Using the direct query method, annual ED anaphylaxis cases increased steadily from 1,454 (2011) to 4,029 (2019) then declined to 3,341 in 2020 during the coronavirus disease 2019 (COVID-19) pandemic. In contrast, inpatient cases remained relatively steady, with a slight decline after 2015 during the ICD version transition, until a significant drop occurred in 2020. Using the indirect queries, anaphylaxis cases increased markedly after the ICD transition year, especially involving drug-related anaphylaxis.

CONCLUSIONS

Nontypical drug associations with anaphylaxis episodes using the ICD-10-CM version of the algorithm suggest poor performance with drug-related codes. Further, the increased granularity of ICD-10-CM identified potential limitations of a previously validated symptom-based ICD-9-CM algorithm used to detect undiagnosed cases.

Trends and determinants of epinephrine prescriptions: a proxy of anaphylaxis epidemiology?

PURPOSE OF REVIEW

Epinephrine autoinjectors (EAIs) are recommended to all patients previously experiencing anaphylaxis reaction in order to prevent further reactions and fatalities. Under that perspective, EAI prescription could be considered as a proxy of anaphylaxis epidemiology. Nevertheless EAI prescription rates are still unacceptably low.

RECENT FINDINGS

The review focuses on potential determinants, in addition to clinical indications, which might impact EAI prescription rates by exploring the scientific literature published within the past 18 months, wherever available. Although some controversial results, age, sex, ethnicity, geographical setting and socioeconomic conditions might influence both physician prescription behaviour and EAIs' accessibility from the patient's side, which hampers the accuracy of EAI prescription as a proxy of anaphylaxis. Low EAI prescription and refill rates have been recorded even in the absence of significant socioeconomic barriers, suggesting that economical limitations only partially account for the issue, and cultural restrictions have also to be considered and addressed.

SUMMARY

In addition to providing the same opportunities in terms of EAI availability in all countries worldwide, implementing the resources for anaphylaxis management in terms of practical knowledge, education, and allergy specialist networks is an urgent need, even in the absence of socioeconomic barriers.

Food allergy in the World Health Organization's International Classification of Diseases (ICD)-11

There are increasing global data regarding the prevalence of food allergy and food-induced anaphylaxis. However, knowledge in morbidity and mortality epidemiological data is still not optimal, and international comparable standards remain poorly accessed. This information could in turn support better clinical practice and possibly prevent future severe reactions and avoidable fatalities. The International Classification of Diseases (ICD) is the standard diagnostic tool used for epidemiology, health management, and clinical purposes supported by the World Health Organization (WHO). It is also used to determine health care payment and reimbursement of providers and health care services in hospitals. Thanks to the academic and technical efforts under the ALLERGY in ICD-11 initiative the pioneer "Allergy and hypersensitivity conditions" section has been built under the "Disorders of the Immune System" chapter of the ICD-11. The "Food hypersensitivity" (FH) subsection is classified under the "Complex allergic or hypersensitivity conditions" section and "Food-induced anaphylaxis" is under the "Anaphylaxis" section. In order to inform the development of strategies to reduce preventable FHs/food allergies, the burden of disease in different healthcare settings and patient populations and their common etiologies need to be understood. Besides, greater specificity regarding clinical conditions and services delivered will provide payers, policy makers, and providers with better information to make major refinements to countries payment and reimbursement systems, including the design and implementation of pay-for-performance program.The new classification addressed to FHs will enable the collection of more accurate epidemiological data to support quality management of patients with FHs/food allergies, and better facilitate health care planning and decision-making and public health measures to prevent and reduce their morbidity and mortality. The improved logic and standardized definitions through the ICD-11 (and other WHO classifications) will also facilitate international comparisons of quality care and the sharing of best practice globally.

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.

Anaphylaxis in Brazil between 2011 and 2019

BACKGROUND

There is a lack of population-based studies of anaphylaxis from low- and middle-income countries. This hampers public health planning and investments and may influence availability of adrenaline auto-injectors.

OBJECTIVE

We conducted the first national population-based study of anaphylaxis hospitalization in Brazil.

METHODS

Descriptive study using routinely reported data to the Brazilian Hospital Information System for the years 2011-2019. Information available is coded based on the International Classification of Diseases (ICD)-10 and covers main cause of hospitalization (primary cause) and any conditions contributing to it (secondary cause).

RESULTS

Over 9 years, we identified 5716 admissions due to anaphylaxis for all causes. The average hospitalization rate related to anaphylaxis was 0.71/100,000 population per year, with a 2.4% (95% CI 1.9%, 2.9%) increase per annum over the study period. Admissions were more frequent among females (52.8%), except for cases due to insect sting. Most admissions occurred in adulthood, from 30 to 59 years (36.3%) but 13.8% in preschool children (0-4 years). There were more young children admitted for food-related anaphylaxis, and more adults admitted for drug/iatrogenic-related anaphylaxis. There were 334 cases (5.8% of admissions) of fatal anaphylaxis over the study period, with increased case fatality rate over time.

CONCLUSIONS AND CLINICAL RELEVANCE

This is the first study of anaphylaxis hospital admissions using nation-wide data from a low- or middle-income country. Hospital admissions and fatalities from anaphylaxis in Brazil appear to be increasing.

What We Know about Sting-Related Deaths? Human Fatalities Caused by Hornet, Wasp and Bee Stings in Europe (1994-2016)

Simple Summary

Information about fatalities due to stinging insects is scarce. Hymenopteran-related deaths (n = 1691) in 32 European countries based on official registers over a 23-year period (1994–2016) are described. Male adults (25–64 years) were the most common group to be fatally injured and almost half of the fatalities were recorded at “unspecified places”. Fatalities per million inhabitants per year ranged from 0 to 2.24 with an average of 0.26. Geographic, environmental, and ecological factors influence the frequency of stings, and its subsequent reaction. It is necessary to produce and interpret knowledge using diverse sources and in an interdisciplinary way. As part of the One Health philosophy, people and hornets, wasps and bees, as well as the environment that they share are closely connected.

Abstract

Epidemiology of Hymenopteran-related deaths in Europe, based on official registers from WHO Mortality Database (Cause Code of Death: X23), are presented. Over a 23-year period (1994–2016), a total of 1691 fatalities were recorded, mostly occurring in Western (42.8%) and Eastern (31.9%) Europe. The victims tended to concentrate in: Germany (n = 327; 1998–2015), France (n = 211; 2000–2014) and Romania (n = 149; 1999–2016). The majority of deaths occurred in males (78.1%) between 25–64 years (66.7%), and in an “unspecified place” (44.2%). The highest X23MR (mortality rate) were recorded in countries from Eastern Europe (0.35) followed by Western (0.28), Northern (0.23) and Southern Europe (0.2). The countries with the highest and lowest mean X23MR were Estonia (0.61), Austria (0.6) and Slovenia (0.55); and Ireland (0.05), United Kingdom (0.06) and the Netherlands (0.06), respectively. The X23 gender ratio (X23GR; male/female) of mortality varied from a minimum of 1.4 for Norway to a maximum of 20 for Slovenia. Country-by-country data show that the incidence of insect-sting mortality is low and more epidemiological data at the regional level is needed to improve our understanding of this incidence. With the expansion of non-native Hymenopteran species across Europe, allergists should be aware that their community’s exposures are continually changing

Allergy in the World Health Organization's International Classification of Diseases (ICD)-11

The International Classification of Diseases (ICD) provides a common language for use worldwide as a diagnostic and classification tool for epidemiology, clinical purposes, and health management. The change in the hierarchy in ICD-11 permitted the construction of the pioneer section addressed to allergic and hypersensitivity conditions (A/H), which may result in more accurate mortality and morbidity statistics, including more accurate accounting for mortality due to anaphylaxis, strengthen classification, terminology, and definitions. The ICD-11 was presented and adopted by the 72nd World Health Assembly in May 2019, and the implementation is ongoing worldwide. The Montpellier World Health Organization (WHO) Collaborating Centre on Classification Scientific Support was designated in 2018 and is responsible for supporting the WHO through representing A/H in the international classifications and quality care of patients from the public health perspective.

Food-induced anaphylaxis morbidity: Emergency department and hospitalization data support preventive strategies

BACKGROUND

Anaphylaxis is a recognized public health issue. There is no doubt that food-induced anaphylaxis (FIA) has tremendous impact on the quality of life of patients and their families and increases direct and indirect costs. FIA is associated with increasing rates of emergency department admissions and hospitalizations and implies the risk of death. Morbidity epidemiological data are a key to tailor public health actions to this non-communicable disease. The aim of this article was to review published morbidity epidemiological data relating to FIA and potential risk factors, in order to provide evidence-based recommendations to reduce the risk of severe adverse outcomes.

METHODS

We identified published studies available in PUBMED/MEDLINE (1966-2020), EMBASE (1980-2020) and CINAHL (1982-2020). The systematic review was carried out using MeSH terms related to FIA ED admissions and hospitalizations.

RESULTS

A total of 25 articles were selected, 80% published in the last 5 years. After critical analysis of methodological and clinical characteristics reported in the data selected, we were able to propose preventive strategies.

CONCLUSION

Anaphylaxis is a recognized public health issue. FIA is associated with increasing rates of ED admissions and hospitalizations and imply in risk of death. More than reviewing and critically interpreting the key patterns related to FIA morbidity published data, we proposed strategies in order to promote quality care of patients suffering from FIA. Our World Health Organization Collaborative Center is deeply involved in this process, and we believe that the proposed strategies will inform future healthcare policies on anaphylaxis. The long-term objective would be to improve clinical care and quality of life of patients and their families, and develop risk-stratified, cost-effective preventive measures.

Validity of hospital ICD-10-GM codes to identify anaphylaxis

PURPOSE

Anaphylaxis (ANA) is an important adverse drug reaction. We examined positive predictive values (PPV) and other test characteristics of ICD-10-GM code algorithms for detecting ANA as used in a multinational safety study (PASS).

METHODS

We performed a cross-sectional study on routine data from a German academic hospital (2004-2019, age ≥ 18). Chart review was used for case verification. Potential cases were identified from the hospital administration system. The main outcome required at least one of the following: any type of specific in-hospital code (T78.2, T88.6, and T80.5) OR specific outpatient code in combination with a symptom code OR in-hospital non-specific code (T78.4, T88.7, and Y57.9) in combination with two symptom codes. PPV were calculated with 95% confidence interval. Sensitivity analyses modified type of codes, unit of analysis, verification criteria and time period. The most specific algorithm used only primary codes for ANA (numbers added in brackets).

RESULTS

Four hundred and sixteen eligible cases were evaluated, and 78 (37) potential ANA cases were identified. PPV were 62.8% (95% CI 51.1-73.5) (main) and 77.4% (58.9-90.4) (most specific). PPV from all modifications ranged from 12.9% to 80.6%. The sensitivity of the main algorithm was 66.2%, specificity 91.5%, and negative predictive value 92.6%. Corresponding figures for the most specific algorithm were 32.4%, 98.0%, and 87.0%.

CONCLUSIONS

The PPV of the main algorithm seems of acceptable validity for use in comparative safety research but will underestimate absolute risks by about a third. Restriction to primary discharge codes markedly improves PPV to the expense of reducing sensitivity.

Prediction of skin disease using a new cytological taxonomy based on cytology and pathology with deep residual learning method

With the development of artificial intelligence, technique improvement of the classification of skin disease is addressed. However, few study concerned on the current classification system of International Classification of Diseases, Tenth Revision (ICD)-10 on Diseases of the skin and subcutaneous tissue, which is now globally used for classification of skin disease. This study was aimed to develop a new taxonomy of skin disease based on cytology and pathology, and test its predictive effect on skin disease compared to ICD-10. A new taxonomy (Taxonomy 2) containing 6 levels (Project 2–4) was developed based on skin cytology and pathology, and represents individual diseases arranged in a tree structure with three root nodes representing: (1) Keratinogenic diseases, (2) Melanogenic diseases, and (3) Diseases related to non-keratinocytes and non-melanocytes. The predictive effects of the new taxonomy including accuracy, precision, recall, F1, and Kappa were compared with those of ICD-10 on Diseases of the skin and subcutaneous tissue (Taxonomy 1, Project 1) by Deep Residual Learning method. For each project, 2/3 of the images were included as training group, and the rest 1/3 of the images acted as test group according to the category (class) as the stratification variable. Both train and test groups in the Projects (2 and 3) from Taxonomy 2 had higher F1 and Kappa scores without statistical significance on the prediction of skin disease than the corresponding groups in the Project 1 from Taxonomy 1, however both train and test groups in Project 4 had a statistically significantly higher F1-score than the corresponding groups in Project 1 (P = 0.025 and 0.005, respectively). The results showed that the new taxonomy developed based on cytology and pathology has an overall better performance on predictive effect of skin disease than the ICD-10 on Diseases of the skin and subcutaneous tissue. The level 5 (Project 4) of Taxonomy 2 is better on extension to unknown data of diagnosis system assisted by AI compared to current used classification system from ICD-10, and may have the potential application value in clinic of dermatology.

SARS-CoV-2 Vaccination and Anaphylaxis: Recommendations of the French Allergy Community and the Montpellier World Health Organization Collaborating Center

Vaccines against COVID-19 (and its emerging variants) are an essential global intervention to control the current pandemic situation. Anaphylactic reactions have been reported after SARS-CoV2 RNA vaccines. Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. This risk is estimated at 1/1,000,000 in the context of vaccine safety surveillance programs. The COVID-19 vaccination is rolling-out vastly in different courtiers and surveillance programs are key to monitor severe adverse reactions, such as anaphylaxis. Anaphylaxis due to vaccine is extremely rare and specific cases should receive individualized investigation and care. The here presented recommendations and follow-up from the French allergy community and the Montpellier WHO Collaborating Center in order to support the vaccination program and intends to support to healthcare professionals in their daily basis.

Epidemiology of anaphylaxis

PURPOSE OF REVIEW

To understand the current global epidemiological data of anaphylaxis and identify potential strategies to improve patients' care and prevention.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics (MMS) may gain new perspectives with the implementation of the International Classification of Diseases (ICD)-11 in the forthcoming years. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate healthcare planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

Anaphylaxis is a complex noncommunicable diseases with adverse impact on health-related quality of life of patients and their carriers and a significant proportion of deaths may be preventable. It requires an integrated holistic plan to improve quality of healthcare and gathering accurate and comparable epidemiological data is key. Morbidity related to anaphylaxis seems to be increasing worldwide whereas mortality of anaphylaxis appears to be low and stable, but this still has great challenges in capturing quality anaphylaxis MMS. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk. As knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support quality management of patients, and better facilitate healthcare planning to implement public health measures to prevent and reduce the morbidity and mortality attributable to these conditions.

Increasing anaphylaxis events in Western Australia identified using four linked administrative datasets

Background

Anaphylaxis events are increasing worldwide, based on studies of single administrative datasets including hospital admissions, emergency room presentations, and prescription and medical claims data. Linking multiple administrative datasets may provide better epidemiological estimates, by capturing a greater number of anaphylaxis events occurring at the individual level. In this linked data study in Western Australia, we combined 4 population-based datasets to identify anaphylaxis events, factors influencing occurrence, and change in event rates from 2002 to 2013.

Methods

Four linked administrative datasets from the Western Australian Data Linkage System were used, representing ambulance attendances, emergency department presentations, hospital inpatient admissions and death registrations. An anaphylaxis cohort was identified using ICD-9-CM, ICD-10-AM and additional anaphylaxis diagnosis codes, with event rates calculated. We explored the impact of age, gender, cause, Indigenous status and socioeconomic index on event rates. Standard Poisson regression models were used to examine the significance of the change in anaphylaxis event rates over time.

Results

A total 12,637 individuals (mean age 31.8 years, 49.6% female) experienced 15,462 anaphylaxis events between 2002 and 2013 (97.5% in non-Indigenous patients and 59.5% residing in the area of greatest socioeconomic advantage). Anaphylaxis event rates increased from 15.4 to 82.5/10⁵ population between 2002 and 2013. The greatest increase in anaphylaxis events was seen in those coded as unspecified anaphylaxis (all ages, males and females combined, p < 0.001), with the highest rates of unspecified anaphylaxis in males 0–4 years (171.9/10⁵ population in 2013), and females 15–19 years (104.0/10⁵ in 2013). The average annual percent increase (95% CI) for food-related anaphylaxis was 9.2% (6.6–12.0); for medication-related anaphylaxis was 5.8% (4.5–7.1); and for unspecified anaphylaxis was 10.4% (9.8–11.0); all p < 0.001. There was a significant increase in ambulance attendance, emergency presentations and inpatient admissions for anaphylaxis between 2002 and 2013, with emergency presentations (56.0/10⁵ population), inpatient admissions (43.2/10⁵), and ambulance attendance (21.6/10⁵) highest in 2013. Only 25 anaphylaxis-related deaths were recorded in the mortality register with no significant change in rates over time.

Conclusion

Using multiple linked administrative datasets, we identified significantly higher rates of total anaphylaxis than previously reported, with more than 5-fold increases in anaphylaxis events between 2002 and 2013. While the combination of 4 population-level datasets provides a more comprehensive capture of cases, even at the individual dataset level, admission rates for anaphylaxis in Western Australia are substantially higher than those previously reported for similar time periods, both in Australia and worldwide.

A Proposal from the Montpellier World Health Organization Collaborating Centre for Better Management and Prevention of Anaphylaxis

Since the first description of anaphylaxis in 1902, its clinical importance as an emergency condition has been recognized worldwide. Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction characterized by rapid onset and the potential to endanger life through respiratory or circulatory compromise. It is usually, although not always, associated with skin and mucosal changes. Although the academic/scientific communities have advocated to promote greater awareness and protocols for the management of anaphylaxis based on best evidence, there are few efforts documenting feedback as to the success of these efforts. In this article, we review the key unmet needs related to the diagnosis and management of anaphylaxis, and propose a public health initiative for prevention measures and a timetable action plan that intends to strengthen the collaboration among health professionals and especially primary care physicians dealing with anaphylaxis, which can encourage enhanced quality of care of patients with anaphylaxis. More than calling for a harmonized action for the best management of anaphylaxis to prevent undue morbidity and mortality, the Montpellier World Health Organization Collaborating Centre here proposes an action plan as a baseline for a global initiative against anaphylaxis. We strongly believe that these collaborative efforts are a strong public health and societal priority that is consistent with the overarching goals of providing optimal care of allergic patients and best practices of allergology.

Fatal anaphylaxis in Italy: Analysis of cause-of-death national data, 2004-2016

BACKGROUND

Epidemiological data on fatal anaphylaxis are underestimated worldwide. Few Italian data do exist. The aims of the study are to determine the anaphylaxis mortality rate in Italy and its associations with demographic characteristics (gender, age, and geographical distribution), and to investigate which are the most common triggers of fatal anaphylaxis.

MATERIAL AND METHODS

This is a descriptive study analyzing data reported to the National Register of Causes of Death database and managed by the Italian National Institute of Statistics for the years 2004-2016. An analytical method was developed to identify all the ICD-10 codes related to anaphylaxis deaths, which were divided into two classes: "Definite anaphylaxis deaths" and "Possible anaphylaxis deaths."

RESULTS

From 2004 through 2016, 392 definite anaphylaxis deaths and 220 possible anaphylaxis deaths were recorded. The average mortality rate for definite anaphylaxis, from 2004 to 2016, was 0.51 per million population per year. Definite fatal anaphylaxis was mostly due to the use of medications (73.7%), followed by unspecified causes (20.7%) and hymenoptera stings (5.6%). Concerning possible anaphylaxis deaths, the most common cause was venom-stinging insect (51.4%). We did not find any data on food fatal anaphylaxis. Unspecified anaphylaxis accounted for 21%-28% of all cases, underlining the difficulty in accurately ascertaining the causes of fatal anaphylaxis and therefore in assigning the proper ICD-10 code.

CONCLUSION

This is the first study of anaphylaxis-related mortality coming from an official database of the whole Italian population. However, the actual number of deaths by anaphylaxis, and their related triggers, is probably underreported, mostly due to limitations of the current recording system, and to a poor allergy education. Corrective actions should be undertaken for the benefit of the Health System.

Global implementation of the world health organization's International Classification of Diseases (ICD)-11: The allergic and hypersensitivity conditions model

The International Classification of Diseases (ICD) provides a common language for use worldwide as a diagnostic and classification tool for epidemiology, clinical purposes and health management. Since its first edition, the ICD has maintained a framework distributing conditions according to topography, with the result that some complex conditions, such as allergies and hypersensitivity disorders (A/H) including anaphylaxis, have been poorly represented. The change in hierarchy in ICD-11 permitted the construction of the pioneer section addressed to A/H, which may result in more accurate mortality and morbidity statistics, including more accurate accounting for mortality due to anaphylaxis, strengthen classification, terminology and definitions. The ICD-11 was presented and adopted by the 72nd World Health Assembly in May 2019, and the implementation is ongoing worldwide. We here present the outcomes from an online survey undertaken to reach out the allergy community worldwide in order to peer review the terminology, classification and definitions of A/H introduced into ICD-11 and to support their global implementation. Data are presented here for 406 respondents from 74 countries. All of the subsections of the new A/H section of the ICD-11 had been considered with good accuracy by the majority of respondents. We believe that, in addition to help during the implementation phase, all the comments provided will help to improve the A/H classification and to increase awareness by different disciplines of what actions are needed to ensure more accurate epidemiological data and better clinical management of A/H patients.

Asthma and anaphylaxis

PURPOSE OF REVIEW

Both asthma and anaphylaxis are recognized noncommunicable hypersensitivity conditions, which should be correctly diagnosed and treated/controlled in order to decrease avoidable deaths. Nevertheless, their association is not completely clear. We here propose to review the current and new evidence-based data of asthma and anaphylaxis in the view of the new knowledge in the field that can support the quality practice and empower allergists and health professionals in treating symptoms and preventing death.

RECENT FINDINGS

Hypersensitivity life-threatening conditions, such as anaphylaxis and asthma can coexist, mimic or worse each other. Asthma itself is not a strong predictor of more severe anaphylaxis. However, poor asthma control associated with more severe anaphylaxis reactions in all ages. In children, asthma is associated with the severity and recurrences of anaphylactic reactions.

SUMMARY

Although recent data point for the association between asthma and anaphylaxis, we still do not have harmonized evidence to confirm if we are dealing with two independent comorbidities one worsening each other. However, as far as this review is covering two relevant public health problems in the field of allergy, it is mandatory put in place decisions supporting recommendations to better manage the affected patients and reduce the risk.General strategies should include regular notification of this association, optimization of the classification and coding for anaphylaxis and asthma (new ICD 11 allergy codes) in order to harmonize epidemiological stratified data, early diagnosis of asthma in childhood, regular investigation of asthma in cases of anaphylaxis and optimization of the asthma control and lung function for all patients with indication to provocation tests, desensitization or allergen immunotherapy regardless to the trigger. Implementation of these strategies will involve national and international support for ongoing efforts in relationship with networks of centres of excellence to provide personalized management for the most at-risk patients and prevent death.

Anaphylaxis diagnosis and management in the Emergency Department of a tertiary hospital in the Philippines

Background

In the Emergency Department (ED), diagnosis and management of anaphylaxis are challenging with at least 50% of anaphylaxis episodes misdiagnosed when the diagnostic criteria of current guidelines are not used.

Objective

Objective of our study was to assess anaphylaxis diagnosis and management in patients presenting to the ED.

Methods

Retrospective chart review conducted on patients presenting to The Medical City Hospital ED, the Philippines from 2013–2015 was done. Cases were identified based on International Statistical Classification of Diseases, 10th revision coding for either anaphylaxis or other allergic related diagnosis. Cases fitting the definition of anaphylaxis as identified by the National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network (NIAID/FAAN) were included. Data collected included demographics, signs and symptoms, triggers and management.

Results

A total of 105 cases were evaluated. Incidence of anaphylaxis for the 3-year study period was 0.03%. Of the 105 cases, 35 (33%) were diagnosed as “urticaria” or “hypersensitivity reaction” despite fulfilling the NIAID/FAAN anaphylaxis criteria. There was a significant difference in epinephrine administration between those given the diagnosis of anaphylaxis versus misdiagnosed cases (61 [87%] vs. 12 [34%], χ² = 30.77, p < 0.01); and a significant difference in time interval from arrival at the ED to epinephrine administration, with those diagnosed as anaphylaxis (48%) receiving epinephrine within 10 minutes, versus ≥ 60 minutes for most of the misdiagnosed group (χ² = 52.97, p < 0.01).

Conclusion

Despite current guidelines, anaphylaxis is still misdiagnosed in the ED. Having an ED diagnosis of anaphylaxis significantly increases the likelihood of epinephrine administration, and at a shorter time interval.

Capturing anaphylaxis through medical records: Are ICD and CPT codes sufficient?

OBJECTIVE

The identification of anaphylaxis cases is imperative for optimal clinicalprovider knowledge deficiencies in diagnosis and treatment and the efficacy of reimbursement codes, such as International Classification of Diseases (ICD) and current procedural terminology (CPT) codes, in detecting anaphylaxis.

DATA SOURCES

Pubmed.

STUDY SELECTIONS

Recent and clinically relevant literature on anaphylaxis and provider knowledge, ICD, CPT, Healthcare Common Procedural Coding System (HCPCS), and E-codes were selected and reviewed.

RESULTS

Reimbursement codes are used to detect anaphylaxis in administrative claims databases. Inaccurate recognition of the diagnosis by providers, underreporting, and cause identification are challenges faced by health researchers using reimbursement codes for anaphylaxis case identification. Anaphylactic shock-specific ICD codes were noted to have a positive predictive value (PPV) of 52% to 53% of anaphylaxis events compared with physician chart review, which was improved to 63% to 67.3% when used in conjunction with anaphylaxis symptom-specific ICD, CPT, HCPCS, and E-codes 31, 34, and 35.

CONCLUSION

Education of providers to properly diagnose and treat anaphylaxis requires systematic and educational investments. The ICD codes specific to anaphylactic shock have suboptimal PPV to identify anaphylaxis in administrative claims databases. Use of algorithms incorporating other reimbursement codes improve the PPV, but they are limited by inaccurate diagnoses and underreporting of anaphylaxis. Future ICD-11 reclassification may improve anaphylaxis detection by reimbursement codes.

Changing the history of anaphylaxis mortality statistics through the World Health Organization's International Classification of Diseases-11

We review the history of the classification and coding changes for anaphylaxis and provide current and perspective information in the field. In 2012, an analysis of Brazilian data demonstrated undernotification of anaphylaxis-related deaths because of the difficulties of coding using the International Classification of Diseases, 10th Revision. This work triggered strategic international actions supported by the Joint Allergy Academies and the International Classification of Diseases World Health Organization (WHO) leadership to update the classification of allergic disorders for the International Classification of Diseases, 11th Revision (ICD-11), which resulted in construction of the pioneer "Allergic and hypersensitivity conditions" chapter. The usability of the new framework has been tested by evaluating the same data published in 2012 from the ICD-11 perspective. Coding accuracy was much improved, reaching 95% for definite anaphylaxis. As the results were provided to the WHO Mortality Reference Group, coding rules have been changed, allowing anaphylaxis to be recorded as an underlying cause of death in official mortality statistics. The mandatory use of ICD-11 from January 2022 for documenting cause of death could have 2 immediate consequences: (1) the reported number of anaphylaxis-related deaths might increase because of more appropriate coding and (2) the cross-sectional and longitudinal mortality data generated might ultimately lead to a better understanding of anaphylaxis epidemiology and improved health policies directed at reducing anaphylaxis-related mortality.

Food-induced fatal anaphylaxis: From epidemiological data to general prevention strategies

BACKGROUND

Anaphylaxis hospitalizations are increasing in many countries, in particular for medication and food triggers in young children. Food-related anaphylaxis remains an uncommon cause of death, but a significant proportion of these are preventable.

AIM

To review published epidemiological data relating to food-induced anaphylaxis and potential risk factors of fatal and/or near-fatal anaphylaxis cases, in order to provide strategies to reduce the risk of severe adverse outcomes in food anaphylaxis.

METHODS

We identified 32 published studies available in MEDLINE (1966-2017), EMBASE (1980-2017), CINAHL (1982-2017), using known terms and synonyms suggested by librarians and allergy specialists.

RESULTS

Young adults with a history of asthma, previously known food allergy particularly to peanut/tree nuts are at higher risk of fatal anaphylaxis reactions. In some countries, cow's milk and seafood/fish are also becoming common triggers of fatal reactions. Delayed adrenaline injection is associated with fatal outcomes, but timely adrenaline alone may be insufficient. There is still a lack of evidence regarding the real impact of these risk factors and co-factors (medications and/or alcohol consumption, physical activities, and mast cell disorders).

CONCLUSIONS

General strategies should include optimization of the classification and coding for anaphylaxis (new ICD 11 anaphylaxis codes), dissemination of international recommendations on the treatment of anaphylaxis, improvement of the prevention in food and catering areas, and dissemination of specific policies for allergic children in schools. Implementation of these strategies will involve national and international support for ongoing local efforts in relationship with networks of centres of excellence to provide personalized management (which might include immunotherapy) for the most at-risk patients.

[Recommendation of ICD-10 codes for surveillance of adverse drug reactions and drug intoxication]

ICD-10 is the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization. It contains codes for diseases, signs and symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or diseases. Associations between variables were evaluated using Pearson's chi-squared test and multiple correspondence analysis. Six hundred and ninety-one (691) codes were identified related to adverse drug reactions (52.1%) and drug poisoning (47.9%). A total of 687 (99.4%) and 511 (73.9%) codes were validated in 1st and 2nd validation, respectively. There were statistically significant differences (p <0.05) between adverse reactions and drug poisoning in the variables used to characterize the reference list. The association between drug and hospital admission and death was statistically significant when stratified by type of adverse event (p <0.001). Three groupings of codes were identified in multiple correspondence analysis where there are associations between categories of response assessed. The reference list can be a useful tool in pharmacovigilance actions in Brazil.

Difficulties Coding Dermatological Disorders Using the ICD-10: The DIADERM Study

BACKGROUND AND OBJECTIVES

The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) has some shortcomings when it comes to coding certain dermatological disorders. To overcome these shortcomings, a compatible version of the ICD-10 specifically adapted to dermatology was produced in Spain in 1999. The recent DIADERM study recorded 10 999 dermatological diagnoses using a representative sample of dermatologists working at outpatient clinics in Spain. The aims of the current study were to identify diagnoses from the DIADERM study that could not be coded using the adapted ICD-10, determine why, and check if they could be coded using the draft ICD-11.

MATERIAL AND METHODS

We included all dermatological diagnoses from the DIADERM study that could not be assigned a code from the adapted ICD-10. We then quantified and recorded all the diagnoses that could not be coded using either the adapted ICD-10 or the draft ICD-11.

RESULTS

Of the 10 999 diagnoses analyzed, 41 had not been assigned a code. Of these, 19 were assigned an adapted ICD-10 code on reassessment. However, the adapted ICD-10 and the draft ICD-11 lacked specific codes for 22 and 17 diagnoses, respectively.

CONCLUSIONS

The adapted ICD-10 can be used to correctly code the vast majority of dermatological diagnoses seen in routine clinical practice. Nevertheless, the system does have some minor shortcomings when it comes to coding certain diseases, particularly newly discovered and emerging diseases. Some of these problems, however, were resolved with the new ICD-11. Based on our findings, we propose some modifications to the ICD-11.

Fatal Anaphylaxis: Mortality Rate and Risk Factors

Up to 5% of the US population has suffered anaphylaxis. Fatal outcome is rare, such that even for people with known venom or food allergy, fatal anaphylaxis constitutes less than 1% of total mortality risk. The incidence of fatal anaphylaxis has not increased in line with hospital admissions for anaphylaxis. Fatal drug anaphylaxis may be increasing, but rates of fatal anaphylaxis to venom and food are stable. Risk factors for fatal anaphylaxis vary according to cause. For fatal drug anaphylaxis, previous cardiovascular morbidity and older age are risk factors, with beta-lactam antibiotics, general anesthetic agents, and radiocontrast injections the commonest triggers. Fatal food anaphylaxis most commonly occurs during the second and third decades. Delayed epinephrine administration is a risk factor; common triggers are nuts, seafood, and in children, milk. For fatal venom anaphylaxis, risk factors include middle age, male sex, white race, cardiovascular disease, and possibly mastocytosis; insect triggers vary by region. Upright posture is a feature of fatal anaphylaxis to both food and venom. The rarity of fatal anaphylaxis and the significant quality of life impact of allergic conditions suggest that quality of life impairment should be a key consideration when making treatment decisions in patients at risk for anaphylaxis.

What can we learn in drug allergy management from World Health Organization's international classifications?

Drug hypersensitivity reactions (DHRs) represent growing health problem worldwide, affecting more than 7% of the general population, and represent an important public health problem. However, knowledge in DHRs morbidity and mortality epidemiological data is still not optimal and international comparable standards remain poorly accessed. Institutional databases worldwide increasingly use the WHO International Classification of Diseases (ICD) system to classify diagnoses, health services utilization, and death data. The misclassification of disorders in the ICD system contributes to a lack of ascertainment and recognition of their importance for healthcare planning and resource allocation. It also hampers clinical practice and prevention actions. To further inform the allergy community and to ensure that the revision process is transparent as advised in the WHO ICD-11 revision agenda, we report the advances and use of the pioneering "Drug hypersensitivity" subsection of ICD-11 and implementation in the WHO International Classification of Health Interventions (ICHI). The new classification addressed to DHRs will enable the collection of more accurate epidemiological data to support quality management of patients with drug allergies and better facilitate healthcare planning and decision-making and public health measures to prevent and reduce the morbidity and mortality attributable to DHRs.

Critical view of anaphylaxis epidemiology: open questions and new perspectives

In contrast to the majority of allergic or hypersensitivity conditions, worldwide anaphylaxis epidemiological data remain sparse with low accuracy, which hampers comparable morbidity statistics. Data can differ widely depending on a number of variables. In the current document we reviewed the forms on which anaphylaxis has been defined and classified; and how it can affect epidemiological data. With regards to the methods used to capture morbidity statistics, we observed the impact of the anaphylaxis coding utilizing the World Health Organization's International Classification of Diseases. As an outcome and depending on the anaphylaxis definition, we extracted the cumulative incidence, which may not reflect the real number of new cases. The new ICD-11 anaphylaxis subsection developments and critical view of morbidity statistics data are discussed in order to reach new perspectives on anaphylaxis epidemiology.