An update on epidemiology of anaphylaxis in children and adults

Update in pediatric anaphylaxis: a systematic review

Anaphylaxis is common in children and has many differences across age groups. A systematic review of the literature from the past 5 years was conducted with the goal of updating the pediatrician. Food is the most common trigger in children, but insect venom and drugs are other typical causes. Clinical diagnostic criteria include dermatological, respiratory, cardiovascular, and gastrointestinal manifestations. A biphasic reaction is seen in some, with recurrence usually within 8 hours of the initial episode. Epinephrine is the drug of choice for acute reactions and the only medication shown to be lifesaving when administered promptly, but it is underutilized. Patients should have ready access to ≥2 doses of an epinephrine autoinjector, with thorough training regarding correct use of a given device and an emergency action plan. Management of anaphylaxis in schools presents distinct challenges. Pediatricians are in a unique position to assess and treat these patients chronically.

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

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

What's new in the diagnosis and management of food allergy in children?

This article reviews the recent advances in the diagnosis and management of IgE mediated food allergy in children. It will encompass the emerging technology of component testing; moves to standardization of the allergy food challenge; permissive diets which allow for inclusion of extensively heated food allergens with allergen avoidance; and strategies for accelerating tolerance and food desensitization including the use of adjuvants for specific tolerance induction.

IgE mediated food allergy in Korean children: focused on plant food allergy

Food allergy (FA) is a worldwide problem, with increasing prevalence in many countries, and it poses a clearly increasing health problem in Korea. In Korea, as a part of International Study of Asthma and Allergy in Childhood (ISAAC), a series of nation-wide population studies for prevalence of allergic disease in children were carried out, with the Korean version of ISAAC in 1995, 2000, and 2010. From the survey, the twelve-month prevalence of FA showed no significant differences from 1995 to 2000 in both age groups (6-12 years-old, 6.5% in 1995 and 5.7% in 2000; 12-15 year-olds, 7.4% in 1995 and 8.6% in 2000). The mean lifetime prevalence of FA which had ever been diagnosed by medical doctor was 4.7% in 6-12 year-olds and 5.1% in 12-15 year-olds respectively in 2000. In Korean children, the major causes of FA are almost same as in other countries, although the order prevalence may vary, a prime example of which being that peanut and tree nut allergies are not prevalent, as in western countries. Both pediatric emergency department (ED) visits and deaths relating to food induced anaphylaxis have also increased in western countries. From a study which based on data from the Korean Health Insurance Review and Assessment Service (KHIRA) from 2001 to 2007, the incidence of anaphylaxis under the age of 19 was 0.7-1 per 100,000 person-year, and foods (24.9%) were the most commonly identified cause of childhood anaphylaxis. In another epidemiologic study, involving 78889 patients aged 0-18 years who visited the EDs of 9 hospitals during June 2008 to Mar 2009, the incidence of food related anaphylaxis was 4.56 per 10,000 pediatric ED visits. From these studies, common causes of food related anaphylaxis were seafood, buckwheat, cow's milk, fruits, peanut and tree nuts. Although systematic epidemiologic studies have not reported on the matter, recently, plant foods related allergy has increased in Korean children. Among 804 children with moderate to severe atopic dermatitis, we reveals that the peanut sensitization rate in Korea reaches 18%, and that, when sensitized to peanut, patients showed a significant tendency to have co-sensitization with house dust mites, egg white, wheat, and soybean. The higher specific IgE to peanut was related to the likelihood of the patient developing severe systemic reactions. In another study, based on the data analysis of 69 patients under 4 years of age who had suspected peanut and tree nut allergy, 22 (31.9%) were sensitized to walnut (>0.35 kU/L, 0.45-27.4 kU/L) and 6 (8.7%) experienced anaphylaxis due to a small amount of walnut exposure. Furthermore, in this review, clinical and immunological studies on plant food allergies, such as buckwheat allergy, rice allergy, barley allergy, and kiwi fruit allergy, in Korean children are discussed.

Anaphylaxis in a tertiary adult allergy clinic: a retrospective review of 516 patients

BACKGROUND

Anaphylaxis is a life-threatening acute allergic reaction that can occur at any age.

OBJECTIVE

To determine the frequency, triggering factors, and clinical features of anaphylaxis among adult patients who were referred to a tertiary health care facility.

METHODS

A retrospective medical chart review was performed including all patients referred to the outpatient clinic of the adult allergy department in our university hospital between January 1, 2008 and December 30, 2011 to determine cases involving anaphylaxis.

RESULTS

A total of 516 (2.11%) patients among 24,443 admissions were diagnosed with anaphylaxis. Although the second highest frequency of anaphylaxis cases took place in 2008, a gradual rise in the frequency was determined from 2009 to 2011. Drugs (90.7%) were the most frequent cause, followed by Hymenoptera stings (5.4%), foods (1.6%), latex (0.4%), and exercise (0.2%) respectively. The clinical manifestations during anaphylaxis reported by patients were cutaneous (n = 292, 56.6%), respiratory (n = 253, 49%), cardiovascular (n = 212, 41%), neuropsychiatric (n = 60, 11.6%), and gastrointestinal (n = 52, 10.1%), respectively. Approximately one fifth of the patients received epinephrine, whereas 43% of patients did not receive epinephrine during their treatment in the emergency room. An epinephrine auto-injector was prescribed to 42 patients (8.1%).

CONCLUSION

In this study, the second pattern of National Institute of Allergy and Infectious Disease (NIAID) and the Food Allergy and Anaphylaxis Network (FAAN) diagnostic criteria for anaphylaxis predominated among adult patients. Drugs were the leading triggering factor, followed by Hymenoptera stings, foods, latex, and exercise, respectively. Atopy, asthma, and allergic rhinitis were rarely detected.

Oral immunotherapy in hen's egg-allergic children increases a hypo-proliferative subset of CD4+ T cells that could constitute a marker of tolerance achievement

BACKGROUND

Food allergy affects a significant number of children and its prevalence, and persistence is undergoing an important increase in the last years. Specific oral tolerance induction (SOTI) is a promising therapy for food allergy. However, little is known about the immune mechanisms implicated in the desensitization to allergens. Our purpose was to study which immune parameters are modified during the process of tolerance achievement with the goal of identifying markers of tolerance induction.

METHODS

We performed an extensive immune analysis in 19 allergic children following SOTI with hen's egg before and after the immunotherapy. Changes in lymphocyte subpopulations and serum cytokines were identified in children with desensitization achievement.

RESULTS

Sixteen children achieved complete tolerance to egg, and the immune analysis reveals that desensitization was accompanied in all the cases by a significant decrease in the percentage and absolute counts of effector-memory CD4+ T cells (T(EM) ) and a marked increase in the absolute counts of a subset of CD4(+) CD38(+) CD45RO(-) cells. Additionally, we also observed a marked reduction in the plasma levels of different Th1 and Th2 cytokines after tolerance achievement.

CONCLUSIONS

Acquisition of tolerance in children after oral immunotherapy is accompanied by a decrease in the T(EM) population and the increase in a particular subset of CD4+ T cells with a hypo-proliferative and non-reactive phenotype. This hypo-proliferative subset of cells could constitute a marker of the development of oral tolerance, and the study of this subset could contribute to the better understanding of the immune responses in allergic subjects.

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

OBJECTIVE

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

DESIGN

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

MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

[Food-associated anaphylaxis. Data from the anaphylaxis registry]

Severe allergic reactions are reported to the anaphylaxis registry in German-speaking countries. The data provides knowledge regarding the diagnosis and management of patients suffering from anaphylaxis. The ranking of the most frequent elicitors inducing anaphylaxis is age-dependent and also influenced by the group which is reporting the data. The list of food allergens inducing anaphylaxis also varies with age. In children and adolescents peanuts are common elicitors of food-dependent anaphylaxis: in adults wheat is the most frequent cause. Furthermore, the data from the anaphylaxis registry provides information about rare triggers, as well as alerting us to those causative agents which are increasing in frequency. The relevance of augmentation factors is most likely age-dependent, whereas co-morbidities including atopic diseases like atopic dermatitis and allergic asthma occur frequently in children suffering from food-dependent anaphylaxis. The present manuscript provides data on food allergens such as peas and cauliflower, which have been reported as rare causes of anaphylaxis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION/RECOMMENDATIONS

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

Non-dioxin-like AhR ligands in a mouse peanut allergy model

Recently, we have shown that AhR activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suppresses sensitization to peanut at least in part by inducing a functional shift toward CD4(+)CD25(+)Foxp3(+) T cells. Next to TCDD, numerous other AhR ligands have been described. In this study, we investigated the effect of three structurally different non-dioxin-like AhR ligands, e.g., 6-formylindolo[3,2-b]carbazole (FICZ), β-naphthoflavone (β-NF), and 6-methyl-1,3,8-trichlorodibenzofuran (6-MCDF), on peanut sensitization. Female C57BL/6 mice were sensitized by administering peanut extract (PE) by gavage in the presence of cholera toxin. Before and during peanut sensitization, mice were treated with FICZ, β-NF, or 6-MCDF. AhR gene transcription in duodenum and liver was investigated on day 5, even as the effect of these AhR ligands on CD4(+)CD25(+)Foxp3(+) T(reg) cells in spleen and mesenteric lymph nodes (MLNs). Mice treated with TCDD were included as a positive control. Furthermore, the murine reporter cell line H1G1.1c3 (CAFLUX) was used to investigate the possible role of metabolism of TCDD, FICZ, β-NF, and 6-MCDF on AhR activation in vitro. TCDD, but not FICZ, β-NF, and 6-MCDF, suppressed sensitization to peanut (measured by PE-specific IgE, IgG1, IgG2a and PE-induced interleukin (IL)-5, IL-10, IL-13, IL-17a, IL-22, and interferon-γ). In addition, FICZ, β-NF, and 6-MCDF treatments less effectively induced AhR gene transcription (measured by gene expression of AhR, AhRR, CYP1A1, CYP1A2, CYP1B1) compared with TCDD-treated mice. Furthermore, FICZ, β-NF and 6-MCDF did not increase the percentage of CD4(+)CD25(+)Foxp3(+) T(reg) cells in spleen and mesenteric lymph nodes compared with PE-sensitized mice, in contrast to TCDD. Inhibition of metabolism in vitro increased AhR activation. Together, these data shows that TCDD, but not FICZ, β-NF, and 6-MCDF suppresses sensitization to peanut. Differences in metabolism, AhR binding and subsequent gene transcription might explain these findings and warrant further studies to investigate the role of the AhR in food allergic responses.

Anaphylactic reactions to oligosaccharides in red meat: a syndrome in evolution

OBJECTIVE

While most allergic responses to food are directed against protein epitopes and occur within 30 minutes of ingesting the allergen, recent studies suggest that delayed reactions may occur, sometimes mediated by IgE antibodies directed against carbohydrate moieties. The objective of this review is to summarize the clinical features and management of delayed hypersensitivity reactions to mammalian meat mediated by IgE antibodies to galactose-alpha 1,3-galactose (alpha-gal), an oligosaccharide.

METHODS

A PubMed search was conducted with MeSH terms: galactosyl-(1,3) galactose, oligosaccharides, cetuximab, allergy/hypersensitivity, and anaphylaxis. Reported cases with alpha-gal-mediated reactions were reviewed. This research study was approved by the Institutional Review Board of East Tennessee State University.

RESULTS

Thirty-two cases of adults presenting with red-meat induced allergy thought to be related to oligosaccharides have been reported in the literature so far, making this a rare and evolving syndrome. Most of these patients demonstrated delayed reactions to beef, as was seen in the case reported by us in this manuscript. IgE specific to alpha-gal was identified in most patients with variable response to skin testing with beef and pork. Inhibition studies in some cases showed that the IgE antibodies to beef were directed towards alpha-gal in the meat rather than the protein. The patients often reported history of tick bites, the significance of which is unclear at present. Reactions to cetuximab, a monoclonal antibody, are mediated by a similar mechanism, with IgE antibodies directed against an alpha-gal moiety incorporated in the drug structure.

CONCLUSION

Alpha-gal is an oligosaccharide recently incriminated in delayed anaphylactic reactions to mammalian meats such as to beef, pork, and lamb. It appears that anaphylactic reactions to the anti-cancer biological agent, cetuximab, may be linked mechanistically to the same process. More studies are required to understand the underlying molecular basis for these delayed reactions in specific, and their broader implications for host defense in general.