Decreasing the undernotification of anaphylaxis deaths in Brazil through the International Classification of Diseases (ICD)-11 revision

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.

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.

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.

Liquid chromatography with tandem mass spectrometric method for determination of 52 antibiotics in human whole blood and urine and application to forensic cases

PURPOSE

A rapid and reliable method was developed and validated for the simultaneous analysis of 52 antibiotics (cephalosporins, penicillins, carbapenems, lincosamides, quinolones, nitroimidazoles, macrolides, sulfonamides, tetracyclines, glycopeptide) in urine and whole blood by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

METHOD

Analytes were extracted by dilution or protein precipitation and analyzed on an Agilent 1260 HPLC system coupled to an Agilent 6470 Triple Quadrupole Mass Spectrometer.

RESULTS

The method attended method validation criteria. The limits of detection were equal or lower than 2.0 ng/mL, whereas the limits of quantification ranged from 0.1 to 10.0 ng/mL, from 0.1 to 5.0 ng/mL, in urine and whole blood, respectively. For all analytes, the bias and intra- and inter-day precision values were less than 14.7%. The ranges of recovery values of all antibiotics were 76.5-124.5% in whole blood and 76.3-121.8% in urine, values of the effects were lower than 25% in two matrices. No evidence of carryover was observed. The study of sample stability showed that almost all analytes were stable at 24 °C for 24 h, all analytes were stable at -20 °C for 14 days and at -80 °C for 30 days. Freeze-thaw cycles stability showed that antibiotics were stable except for imipenem. Autosampler stability study showed that all analytes were stable for 24 h, except for imipenem and amoxicillin. Applicability was proven by analyzing authentic whole blood (n = 86) and urine (n = 79) samples from patients under antibiotics treatment. Therefore, this method was applied to the analysis 3 forensic allergy cases, which were positive for at least one analyte.

CONCLUSIONS

A simple, sensitive and high-throughput method for the simultaneous determination of different classes of antibiotics in urine and whole blood samples was developed and applied. This sensitive method was successfully applied to forensic cases.

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.

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.

Economic burden of drug-induced anaphylaxis: what can we do better?

PURPOSE OF REVIEW

This systematic review evaluates published data related to the economic burden of drug-induced anaphylaxis (DIA) to understand preventive cost saving measures that could reduce the burden of these conditions.

RECENT FINDINGS

Although DIA has a relevant societal impact, there are limited and heterogenous available data related to its cost. Direct costs related to the management of acute phase of DIA was estimated by $529.6 to $3125, depending on the number of emergency room visits/hospitalizations, emergency kits and transports in ambulance. Direct costs of investigations of DIA varied from $288 to $2292.95 and the desensitization was estimated by $6796. Main variables for this were: personnel, allergy screening procedures, medical consumables and space cost. The mean indirect cost was based on a mean absenteeism of 3 days per DIA corresponding to $381.2.

SUMMARY

More than reviewing the published data, we were able to identify variables that, if correctly managed, can reduce the economic burden of DIA, such as adjusting the timing of referral and etiological diagnosis, identification of potential risk and/or co-factors, correct written recommendations to patients. The evidence presented highlights the need of optimization of healthcare patients to patients suffering from DIA.

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.

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.

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.

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.

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.

Highlights and recent developments in food and drug allergy, and anaphylaxis in EAACI Journals (2017)

This review highlights research advances and important achievements in food allergy, anaphylaxis, and drug allergy that were published in the Journals of the European Academy of Allergy and Clinical Immunology (EAACI) in 2017. Food allergy and anaphylaxis research have continued to rapidly accelerate, with increasing numbers of outstanding developments in 2017. We saw new studies on the mechanisms, diagnosis, prevention of food allergy, and novel food allergens. Drug hypersensitivity, as well as hereditary angioedema, has been highlighted in the present review as the focus of recent developments. The EAACI owns three journals: Allergy, Pediatric Allergy and Immunology (PAI), and Clinical and Translational Allergy (CTA). One of the major goals of the EAACI is to support health promotion in which prevention of allergy and asthma plays a critical role and to disseminate the knowledge of allergy to all stakeholders including the EAACI junior members. This paper summarizes the achievements of 2017 in anaphylaxis, and food and drug allergy.

New modalities of allergen immunotherapy

Allergen immunotherapy is a rapidly evolving field. Although subcutaneous immunotherapy has been practiced for over a hundred years, improved understanding of the underlying immunological mechanisms has led to the development of new, efficacious and better tolerated allergen-derivatives, adjuvants and encapsulated allergens. Diverse routes of allergen immunotherapy - oral, sublingual, epicutanoeus and intralymphatic - are enabling immunotherapy for anaphylactic food allergies and pollen-food allergy syndrome, while improving the tolerability and effectiveness of aeroallergen immunotherapy. The addition of Anti-IgE therapy decreases adverse effects of subcutaneous and oral immunotherapy.

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.

How to manage anaphylaxis in primary care

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction characterized by rapidly developing airway and/or circulation problems. It presents with very different combinations of symptoms and apparently mild signs and can progress to fatal anaphylactic shock unpredictably. The difficulty in recognizing anaphylaxis is due, in part, to the variability of diagnostic criteria, which in turn leads to a delay in administration of appropriate treatment, thus increasing the risk of death. The use of validated clinical criteria can facilitate the diagnosis of anaphylaxis. Intramuscular epinephrine (adrenaline) is the medication of choice for the emergency treatment of anaphylaxis. Administration of corticosteroids and H1-antihistamines should not delay the administration of epinephrine, and the management of a patient with anaphylaxis should not end with the acute episode. Long-term management of anaphylaxis should include avoidance of triggers, following confirmation by an allergology study. Etiologic factors suspected in the emergency department often differ from the real causes of anaphylaxis. Evaluation of patients with a history of anaphylaxis should also include an assessment of personal data, such as age and comorbidities, which may increase the risk of severe reactions. Special attention should also be paid to co-factors, as these may easily confound the cause of the anaphylaxis. Patients experiencing anaphylaxis should administer epinephrine as soon as possible. Education (including the use of Internet and social media), written personalized emergency action plans, and self-injectable epinephrine have proven useful for the treatment of further anaphylaxis episodes.

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.

Field-testing the new anaphylaxis' classification for the WHO International Classification of Diseases-11 revision

BACKGROUND

To consolidate the new classification model addressed to the allergic and hypersensitivity conditions according to the International Classification of Diseases (ICD)-11 revision timeline, we here propose real-life application of quality assurance methodology to evaluate sensitivity and accuracy of the 'Anaphylaxis' subsection.

METHODS

We applied field-testing methodology by analysing all the consecutive inpatients' files documented as allergies from the University Hospital of Montpellier electronic database for the period of 1 year. The files clinically validated as being anaphylaxis were manually blind-coded under ICD-10 and current ICD-11 beta draft. The correspondence of coding and the impressions regarding sensibility were evaluated.

RESULTS

From all 2318 files related to allergic or hypersensitivity conditions, 673 had some of the anaphylaxis ICD-10 codes; 309 files (46%) from 209 patients had anaphylaxis and allergic or hypersensitivity comorbidities description. The correspondence between the two coders was perfect for 162 codes from all 309 entities (52.4%) (Cohen-kappa value 0.63) with the ICD-10 and for 221 codes (71.5%) (Cohen-kappa value 0.77) with the ICD-11. There was a high agreement regarding sensibility of the ICD-11 usability (Cohen-kappa value 0.75).

CONCLUSION

We here propose the first attempt of real-life application to validate the new ICD-11 'Anaphylaxis' subsection. Clearer was the improvement in accuracy reaching 71.5% of agreement when ICD-11 was used. By allowing all the relevant diagnostic terms for anaphylaxis to be included into the ICD-11 framework, WHO has recognized their importance not only to clinicians but also to epidemiologists, statisticians, healthcare planners and other stakeholders.

Fatal anaphylaxis registries data support changes in the who anaphylaxis mortality coding rules

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. The difficulty of coding anaphylaxis fatalities under the World Health Organization (WHO) International Classification of Diseases (ICD) system is recognized as an important reason for under-notification of anaphylaxis deaths. On current death certificates, a limited number of ICD codes are valid as underlying causes of death, and death certificates do not include the word anaphylaxis per se. In this review, we provide evidences supporting the need for changes in WHO mortality coding rules and call for addition of anaphylaxis as an underlying cause of death on international death certificates. This publication will be included in support of a formal request to the WHO as a formal request for this move taking the 11^th ICD revision.