Incidence Rate Of Anaphylaxis Research Articles

COVID-19 vaccine safety: Background incidence rates of anaphylaxis, myocarditis, pericarditis, Guillain-Barré Syndrome, and mortality in South Korea using a nationwide population-based cohort study.

To properly assess an association between vaccines and specific adverse events requires a comparison between the observed and background rates; however, studies in South Korea are currently limited. Therefore, in this study, we estimated the background incidence of anaphylaxis, myocarditis, pericarditis, Guillain-Barré syndrome (GBS), and mortality in South Korea. A retrospective cohort study was conducted using the National Sample Cohort (NSC) data. Using NSC, the background incidence rate was estimated by dividing the number of episodes during 2009-2019 by the total population by year and then multiplying by 100,000. Using Statistics Korea data, the background mortality rate was estimated by dividing the number of deaths, during 2009-2019 by the standard population for that year and then multiplying by 100,000. Using background mortality rates, we predicted mortality rates for 2021 using autoregressive integrated moving average models. Further, the expected mortality rates were compared with observed mortality rates. The age-adjusted incidence rate (AIR) of anaphylaxis increased from 4.28 to 22.90 cases per 100,000 population (p = 0.003); myocarditis showed no significant increase, changing from 0.56 to 1.26 cases per 100,000 population (p = 0.276); pericarditis increased from 0.94 to 1.88 cases per 100,000 population (p = 0.005); and GBS increased from 0.78 to 1.21 cases per 100,000 population (p = 0.013). The age-adjusted mortality rate decreased from 645.24 to 475.70 deaths per 100,000 population (p <0.001). The 2021 observed/expected mortality rates for overall (ratio: 1.08, 95% confidence interval [CI]: 1.07-1.08), men (ratio: 1.07, 95% CI: 1.07-1.08), and women (ratio: 1.08, 95% CI: 1.07-1.09), were all significantly higher. When stratified by age group, those aged ≥80 (ratio: 1.16, 95% CI: 1.15-1.17), 60-69 (ratio: 1.11, 95% CI: 1.10-1.13), and 20-29 years old (ratio: 1.07, 95% CI: 1.02-1.13) were also significantly higher. Through the estimation of background rates related to anaphylaxis, myocarditis, pericarditis, GBS, and mortality, we established a reference point for evaluating the potential excess occurrence of adverse events following COVID-19 vaccination. This reference point serves as substantive evidence supporting the safety profile of COVID-19 vaccines.

Incidence of anaphylaxis to YF-VAX® yellow fever vaccination: a retrospective evaluation of vaccine adverse event reports 1999-2018.

The incidence of anaphylaxis after receipt of yellow fever (YF) vaccine is highly variable based upon previously published reports. Anaphylaxis after receiving the YF vaccine has been reported to range from 0 up to 22 per 1 000 000 doses. Our clinical experience suggested increased incidence, which prompted our investigation. We sought to evaluate the current incidence rate of anaphylaxis after receipt of the 17D-204 strain YF-VAX® brand reported in the US. We performed a retrospective review of the Vaccine Adverse Event Reporting System (VAERS) reports of anaphylaxis after receiving the YF-VAX vaccine occurring between 1 October 1999 and 30 September 2018. We utilized the Brighton Collaboration Case Definition and inclusion determination was made by a board-certified allergist. We also obtained the total number of YF-VAX doses distributed across the US during this same time-period and then calculated an updated incidence rate of YF-VAX vaccine-associated anaphylaxis. We identified 132 potential cases of possible or probable anaphylaxis. Of these, 111 met inclusion criteria: level 1 (n = 51), level 2 (n = 59) and level 3 (n = 1). The manufacturer reported a total distribution of 7 624 160 doses of YF-VAX from 1 October 1999 to 30 September 2018. The calculated incidence rate of YF-VAX vaccine-associated anaphylaxis is estimated at 14.6 events per 1 000 000 doses. We conclude the estimated rate of anaphylaxis per VAERS reports is 14.6 events per 1 000 000 doses after YF-VAX vaccination. This is consistent with some previous reports and substantially higher than rates of anaphylaxis after other vaccines.

846-P: Risk of Anaphylaxis among New Users of Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs)

GLP-1 RAs are peptides used to treat patients with T2D. Anaphylaxis has been observed with these treatments, and in the lixisenatide development program, more cases of anaphylaxis were reported for lixisenatide than placebo (0.2% vs 0.1%). The aim was to assess anaphylaxis incidence rates (IRs) among patients with T2D initiating GLP-1 RAs, with a focus on lixisenatide. We conducted a cohort study in 3 large US claims databases using data from 2017-2021. We included new users of GLP-1 RAs with T2D aged ≥18 years and enrolled ≥6 months in the database before GLP-1 RA initiation (start of follow-up). Medications included were: lixisenatide and insulin glargine/lixisenatide, exenatide, liraglutide and insulin degludec/liraglutide, dulaglutide, and semaglutide. We identified the first anaphylaxis event during follow-up using a validated algorithm. We report anaphylaxis crude IRs and 95% confidence intervals (CIs) for each medication cohort, pooled across data sources. There were 696,089 new users with 456,612 person-years (p-y) of exposure to GLP-1 RAs. Baseline characteristics (demographics, medications, medical conditions) were similar across the medication cohorts. IRs ranged from 1.0 (lixisenatide) to 6.0 (exenatide) per 10,000 p-y with wide 95% confidence intervals (Figure). Anaphylaxis is rare with GLP-1 RA treatments. Lixisenatide is unlikely to confer higher risk of anaphylaxis than other GLP-1 RAs. Disclosure M.S.Anthony: Other Relationship; Sanofi. C.W.Saltus: Other Relationship; Sanofi. S.Berreghis: Employee; Sanofi. L.E.Parlett: Employee; HealthCore Inc., Research Support; Sanofi. C.Bocage: Employee; Anthem, Inc, Stock/Shareholder; Anthem, Inc. K.E.Walsh: Consultant; Sanofi. J.Juhaeri: Employee; Sanofi. C.Johannes: Other Relationship; Sanofi-Aventis U.S. L.Djebarri: Employee; Sanofi. D.C.Beachler: Employee; Anthem, Inc, HealthCore Inc. V.R.Aroda: Consultant; Applied Therapeutics Inc., Fractyl Health, Inc., Novo Nordisk, Pfizer Inc., Sanofi, Other Relationship; Janssen Pharmaceuticals, Inc., Research Support; Applied Therapeutics Inc., Eli Lilly and Company, Fractyl Health, Inc., Novo Nordisk, Sanofi. B.Calingaert: Other Relationship; Sanofi. C.Pan: None. C.Crowe: Employee; HealthCore Inc. S.Lanes: None. K.J.Rothman: None.

Incidence Rate of Bee Venom Acupuncture Related Anaphylaxis: A Systematic Review.

Background: Bee venom acupuncture (BVA) is an effective treatment method for various diseases. Bee venom, however, can cause adverse effects, even rarely including life-threatening anaphylaxis, so safety-related evidence is required. In this study, we systematically estimated the incidence rate of anaphylaxis in response to BVA. Methods: We searched eight databases (MEDLINE (Pubmed), EMBASE, Cochrane Central Register of Controlled, KISS, KMBASE, Koreamed, OASIS, and NDSL) and systematically reviewed the articles that met the inclusion/exclusion criteria. Results: Among 225 potentially relevant articles, 49 were selected for this study. The overall incidence rate of anaphylaxis in response to BVA was 0.045% (95% CI 0.028–0.062). Women (0.083%, 95% CI 0.010–0.157) showed a higher incidence rate than men (0.019%, 95% CI −0.018 to 0.055), while the incidence for patients who had a skin test conducted (0.041%, 95% CI 0.011–0.072) was not significantly different compared to that obtained for patients for which there was no information about a skin test (0.047%, 95% CI 0.026–0.067). The publication year affected the incidence rate: it was highest before 1999 (1.099%, 95% CI −1.043 to 3.241), lower between 2000 and 2009 (0.049%, 95% CI 0.025–0.073), and lowest between 2010 and 2021 (0.037% 95% CI 0.014–0.060). Conclusions: In this study, we provide reference data about risk size and factors of BVA-related anaphylaxis, which is essentially required for BVA application in clinics.

Comorbidities and Cofactors of Anaphylaxis in Patients with Moderate to Severe Anaphylaxis. Analysis of Data from the Anaphylaxis Registry for West Pomerania Province, Poland.

Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction that is still rarely diagnosed. For safety reasons, patients should visit an allergologist to identify potential causes and cofactors of this reaction. This paper presents the analysis of data from the Anaphylaxis Registry gathered over ten years at the Allergy Clinic, Pomeranian Medical University (PMU). A questionnaire-based survey was used for patients visiting the Allergy Clinic to identify potential augmentation factors/comorbidities and/or cofactors of anaphylaxis in patients with a history of moderate to severe anaphylaxis. The registry comprised patients with grade II or higher anaphylaxis. The gathered data concerned chronic comorbidities (cardiovascular diseases, respiratory diseases, and others), recurrence of anaphylaxis, and potential cofactors in anaphylaxis. In the analyzed group, the incidence rate of anaphylaxis was the highest for women aged 19–60 years. Most common comorbidities in patients with moderate to severe anaphylaxis included: cardiovascular diseases, respiratory tract diseases, features of atopy, and thyroid diseases. More than 30% of drug-induced reactions were anaphylactic reactions due to the re-exposure to the same drug, which points to the need for educational initiatives in this area. The incidence rate of anaphylaxis induced by Hymenoptera stings was comparable in patients who had a previous generalized reaction and those who had good tolerance to the previous sting. It is important to take these cofactors into consideration when evaluating patients with anaphylaxis as they may play a role in future anaphylactic reactions.

Increasing incidence of anaphylaxis in Hong Kong from 2009 to 2019\u2014discrepancies of anaphylaxis care between adult and paediatric patients

BackgroundAnaphylaxis has been increasing in developed countries but there is very little published data on the burden of anaphylaxis and the pattern of adrenaline autoinjector (AAI) prescription from Asia. We aim to determine the incidence rates of anaphylaxis and prescription rates of AAI over the past decade in Hong Kong.MethodsUsing a centralized electronic database of Hong Kong’s sole public-funded healthcare provider, we obtained and analysed all patients between 2009 and 2019 with physician-reported diagnosis of anaphylaxis. Incidence rates were calculated using population statistics as the denominator. Patients’ prescriptions on discharge were collected to determine the AAI prescription rates.ResultsThe overall 10-year estimated incidence rate of anaphylaxis was 3.57 per 100,000 person-years. An increasing trend over time across both paediatric and adult populations from 2009 to 2014 was found, which remained stable until 2019. This was more marked among the paediatric population (paediatric vs adult incidence rate ratio in 2019: 3.51 [95% CI 1.12–2.66] vs 1.82 [95% CI 1.05–1.60]). There was an overall increasing rate of AAI prescription for patients admitted for anaphylaxis, but the overall AAI prescription rate was less than 15% and was significantly less likely to be prescribed for the adult compared to paediatric patients (36.5% vs. 89.4%, p < 0.001).ConclusionsAn increasing trend of anaphylaxis incidence rates over the past decade is evident in Asian populations, with a discrepantly low rate of AAI prescription, particularly in the adult patients.

Incidence Rate of Hypersensitivity Reactions to Bee-Venom Acupuncture.

IntroductionBee-venom acupuncture (BVA) has been widely applied to various disorders including pain-related diseases; however, patients are often warned of adverse reactions such as anaphylaxis. This study aimed to estimate the risk of hypersensitivity reactions to BVA and to determine their clinical features.MethodsWe retrospectively surveyed the medical records of patients treated by BVA between January 2010 and April 2019 in Dunsan Hospital of Daejeon University, and all cases of allergic reactions and their clinical symptoms were analyzed.ResultsA total of 8,580 patients (males 4,081 and females 4,499) were treated with BVA which amounts to a total of 60,654 treatments (average 7.1 ± 14.8 times). A total of fifteen patients (7 males and 8 females) reported an allergic reaction (0.175%, 95% CI, 0.086–0.263) of type 1 hypersensitivity, indicating a rate of allergic reaction in 0.025% (95% CI, 0.012–0.037) of the total BVA treatments. The average number of BVA treatments in those patients was 6.9 ± 6.5 (males: 4.1 ± 3.4 and females: 9.3 ± 7.9). Among the cases of hypersensitivity reactions, 4 involved anaphylactic shock; therefore, the incidence rate of anaphylaxis was 0.047% (95% CI, 0.001–0.092) for the 8,580 subjects and 0.007% (95% CI, 0.000–0.013) for the 60,654 treatments. All grade 1 cases were recovered within 1 day, whereas others took up to 30 days for complete recovery.ConclusionOur results may emphasize paying attention to unforeseeable risks of anaphylaxis after bee-venom acupuncture. This study could be essential reference data for the guidelines of appropriate use of bee-venom acupuncture and bee-venom-derived interventions in clinical applications.

Antibiotic prophylaxis for the prevention of infective endocarditis for dental procedures is not associated with fatal adverse drug reactions in France.

BackgroundOne of the major reasons to stop antibiotic prophylaxis (AP) to prevent infective endocarditis (IE) in the United Kingdom but not in the rest of the world was that it would result in more deaths from fatal adverse drug reactions (ADRs) than the number of IE deaths. The main aim of this study was to quantify and describe the ADRs with amoxicillin or clindamycin for IE AP. The second aim was to infer a crude incidence of anaphylaxis associated with amoxicillin for IE AP.Material and MethodsThe Medical Dictionary for Regulatory Activities (MedDRA) was used to group ADRs for IE AP using the broad Standardized MedDRA Queries “Anaphylactic reaction, Amoxicillin, Clindamycin, Clostridium Difficile infection” to the French Pharmacovigilance Database System. From this first-line collection, we selected all cases occurring for IE AP and ultimately, the cases for IE AP for a dental procedure. Then, each case was analyzed.ResultsOf 11639 first-line recorded ADRs, 100 were for IE AP but no fatal anaphylaxis to amoxicillin or clindamycin and no C. difficile infection associated with clindamycin were identified. Only 17 cases of anaphylaxis to amoxicillin related to dental procedures were highlighted. The estimation of the crude incidence rate of anaphylaxis associated with amoxicillin for IE AP for invasive dental procedure was 1/57 000 (95% CI 0.2-0.6).ConclusionsFatal or severe ADRs with amoxicillin or clindamycin is not a rational argument to stop IE AP before invasive dental procedures. Key words:Infective endocarditis, antibiotic prophylaxis, anaphylaxis, adverse drug reaction, amoxicillin, clindamycin, pharmacovigilance.

Patients with urticaria are at a higher risk of anaphylaxis: A nationwide population-based retrospective cohort study in Taiwan.

The clinical features of urticaria and anaphylaxis are similar, and they share common causal immune-mediated pathways. We aimed to investigate the risk of anaphylaxis among patients with urticaria. A 12-year population-based retrospective cohort study was conducted. Investigated subjects were identified from the Taiwan National Health Insurance Research Database by the International Classification of Disease, Ninth Revision, Clinical Modification. We included 126 031 subjects with newly diagnosed urticaria and 252 062 matched controls between 2000 and 2013. Risk of anaphylaxis among patients with urticaria was calculated by calculating adjusted hazards ratios (HR) after matching for confounding comorbidities. Urticaria was more common in women than it was in men (58% vs 42%), with a peak onset age of 20-40 years. The number of comorbidities including asthma, allergic rhinitis, herpes zoster, hepatitis B and C, rheumatoid arthritis and gout were higher in patients with urticaria than that in age- and sex-matched controls. The crude HR for anaphylaxis among urticaria subjects was 2.883 (95% confidence interval [CI], 2.787-2.982; P < 0.001). After adjustment for potential confounders which have been proposed to increase the risk of anaphylaxis, patients with urticaria were found to be at a significantly high risk of anaphylaxis with an adjusted HR of 2.529 (95% CI, 2.442-2.619; P < 0.001). We conclude that the incidence rate of anaphylaxis is significantly high in patients with urticaria in Taiwan.

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

Background Anaphylaxis is a severe, potentially fatal, and systemic allergic reaction. Previous studies document increasing trends in incidence rates of anaphylaxis-related events in Western countries, yet little is known about the incidence and trend of anaphylaxis in Asia. In this study, we aimed to determine time trends in incidence rates of anaphylaxis-related events in Taiwan from 2001 through 2013.Methods We utilized medical claims data from the National Health Insurance Research Databases in Taiwan. We identified anaphylaxis-related events (ICD-9-CM-codes: 995.0, 995.60–995.69, 999.41–999.42, and 999.49) and calculated incidence rates. Poisson regression models were applied to examine trends and incidence rates.Results A total of 2496 patients (mean age, 45.11 years; 56% male) with first-time anaphylaxis were identified during 34,430,000 person-years of observation time. The overall incidence of anaphylaxis was 7.25 (95% confidence interval (CI) = 6.97–7.53) per 100,000 person-years, increasing from 4.79 in 2001 to 8.20 in 2013, with an incidence rate ratio (IRR) of 1.05 (95%CI = 1.04–1.06). Over the 13-year period, the increasing trends were found in incident diagnosis of anaphylaxis-related outpatient or emergency department visits (IRR = 1.06, 95%CI = 1.05–1.08) and admissions to intensive care units (IRR = 1.06, 95%CI = 1.03–1.10), whereas the trends in incidence of anaphylaxis-related hospitalizations remained steady. The proportion of patients requiring hospitalizations among all patients with anaphylaxis (p_trend = 0.01), as well as the proportion requiring intensive care treatment among patients who were hospitalized (p_trend = 0.01), both increased with age.Conclusion The incidence rate of anaphylaxis in Taiwan has increased at an average rate of 5% annually since 2001, paralleling the rising trends in several Western countries.

Patterns of anaphylaxis after diagnostic workup: A follow-up study of 226 patients with suspected anaphylaxis.

Most published studies on anaphylaxis are retrospective or register based. Data on subsequent diagnostic workup are sparse. We aimed to characterize patients seen with suspected anaphylaxis at the emergency care setting (ECS), after subsequent diagnostic workup at our Allergy Center (AC). Prospective study including patients from the ECS, Odense University Hospital, during May 2013-April 2014. Possible anaphylaxis cases were daily identified based on a broad search profile including history and symptoms in patient records, diagnostic codes and pharmacological treatments. At the AC, all patients were evaluated according to international guidelines. Among 226 patients with suspected anaphylaxis, the diagnosis was confirmed in 124 (54.9%) after diagnostic workup; 118 of the 124 fulfilled WAO/EAACI criteria of anaphylaxis at the ECS, while six were found among 46 patients with clinical suspicion but not fulfilling the WAO/EAACI criteria at the ECS. The estimated incidence rate of anaphylaxis was 26 cases per 100 000 person-years and the one-year period prevalence was 0.04%. The most common elicitor was drugs (41.1%) followed by venom (27.4%) and food (20.6%). In 13 patients (10.5%), no elicitor could be identified. Mastocytosis was diagnosed in 7.7% of adult patients and was significantly associated with severe anaphylaxis. Atopic diseases were significantly associated only with food-induced anaphylaxis. Cofactors were present in 58.1% and were significantly associated with severe anaphylaxis. A broad search profile in the ECS and subsequent diagnostic workup is important for identification and classification of patients with anaphylaxis. Evaluation of comorbidities and cofactors is important.

True rise in anaphylaxis incidence: Epidemiologic study based on a national health insurance database.

The incidence trend of anaphylaxis in Asia is not well investigated. The aim of this study is to estimate the entire population-based incidence of anaphylaxis in Korea using a nationwide administrative database.Data over a 7-year period (2008–2014) was obtained from the Korean National Health Insurance (NHI) claims database which covers 97.9% of the entire Korean population. Using diagnosis codes from the International Classification of Diseases-10 for anaphylaxis (T78.0, T78.2, T80.5, and T88.6), we identified the annual number of patients who had visited any hospital with a primary diagnosis of anaphylaxis. Incidence rates were calculated using the population distribution data of all NHI beneficiaries.The incidence of anaphylaxis in Korea was 32.19 episodes per 100,000 person-years in 2014, which nearly doubled from 2008 (16.02 episodes per 100,000 person-years). The incidence of anaphylaxis increased continuously throughout these years regardless of gender and age groups (P for trend < 0.001). Female was significantly less predisposed than male (adjusted odds ratio [OR], 0.69; 95% confident interval [CI], 0.66–0.72; P < 0.001). The incidence was the lowest in 0 to 19 age group and the highest in 40 to 69 age group (adjusted OR, 2.41; 95% CI, 2.29–2.54; P < 0.001).In conclusion, we report the increasing time trend of anaphylaxis incidence rates using nationwide claims database for the first time in Asia.

Trends, characteristics, and incidence of anaphylaxis in 2001-2010: A population-based study

Anaphylaxis is a potentially life-threatening systemic allergic reaction. We aimed to determine the incidence rate and causes of anaphylaxis during a 10-year period in Olmsted County, Minnesota. Using the resources of the Rochester Epidemiology Project, a comprehensive records linkage system, we performed a population-based incidence study in Olmsted County, Minnesota, from 2001 through 2010. All cases with a diagnosis of anaphylactic shock and 20% of cases with related diagnoses were manually reviewed. The relationships of age group, sex, and year of anaphylaxis with incidence rates were assessed by fitting Poisson regression models. Six hundred thirty-one cases of anaphylaxis were identified. The median age was 31years (interquartile range, 19-44years). The overall age- and sex-adjusted incidence rate was 42 (95% CI, 38.7-45.3) per 100,000 person-years. There was a significant increase in the overall incidence of anaphylaxis during the study period, with an average increase of 4.3% per year (P<.001). In addition, there was a 9.8% increase per year in the incidence rate of food-related anaphylaxis. Food-related anaphylaxis was most common in children aged 0 to 9years, venom-related anaphylaxis was most common in those 20 to 39years of age, and medication-related anaphylaxis was most common in those 30 to 39years of age. The overall incidence rate of anaphylaxis was 42 per 100,000 person-years from 2001-2010 in Olmsted County, Minnesota. The incidence of anaphylaxis increased over time,and several inciting triggers were uniquely associated withdifferent age groups.

Anaphylaxis and ethnicity: higher incidence in British South Asians.

The incidence of anaphylaxis in South Asians (Indian, Pakistani and Bangladeshi ethnicity) is unknown. Birmingham is a British city with a disproportionately large population of South Asians (22.5%) compared with the rest of the UK (4.9%). The main aims of this study were to determine the incidence and severity of anaphylaxis in this population and to investigate the differences between the South Asian and White populations. A retrospective electronic search of emergency department attendances at three hospitals in Birmingham during 2012 was carried out. Wide search terms were used, medical notes were scrutinized, and the World Allergy Organization diagnostic criteria for anaphylaxis were applied. Patients' age, sex, ethnicity and home postal code were collected, reactions were graded by severity, and other relevant details including specialist assessment were extracted. Multivariate analysis was undertaken using 2011 UK census data. Age-, sex- and ethnicity-standardized incidence rate of anaphylaxis was 34.5 per 100 000 person-years. Multivariate logistic regression which controlled for the confounders of age, sex and level of socioeconomic deprivation showed that incidence was higher in the South Asian population (OR 1.48, P = 0.005). Incidence rate in the South Asian population was 58.3 cases per 100 000 person-years compared to 31.5 in the White population. South Asian children were more likely to present with severe anaphylaxis (OR 5.31, P = 0.002). Incidence of anaphylaxis is significantly higher in British South Asians compared to the white population. British South Asian children are at a greater risk of severe anaphylaxis than White children.

Pediatric anaphylactic adverse events following immunization in Victoria, Australia from 2007 to 2013

BackgroundAnaphylaxis is a rare life-threatening adverse event following immunization (AEFI). Variability in presentation can make differentiation between anaphylaxis and other AEFI difficult. This study summarizes pediatric anaphylaxis AEFI reported to an Australian state-based passive surveillance system. MethodsAll suspected and reported pediatric (<18 years) anaphylaxis AEFI notified to SAEFVIC (Surveillance of Adverse Events Following Vaccination In the Community) Melbourne, Australia, between May 2007 to May 2013 were analyzed. Clinical descriptions of the AEFI, using the internationally recognized Brighton Collaboration case definition (BCCD) and final outcome were documented. Results93% (25/27) of AEFI classified as anaphylaxis met BCCD criteria, with 36% (9/25), assessed as the highest level of diagnostic certainty (Level 1). Median age was 4.7 years (range 0.3–16.2); 48% of cases were male. The vaccine antigens administered included: diphtheria, tetanus, acellular pertussis (DTaP) alone or in combination vaccines containing other antigens in 11 of 25 cases (44%); and live attenuated measles mumps rubella (MMR) vaccine for six (five also had other vaccines concomitantly administered). The estimated incidence rate of anaphylaxis for DTaP vaccines was 0.36 cases per 100,000 doses, and 1.25 per 100,000 doses for MMR vaccines. The majority of cases had rapid onset, but in 24% (6/25) of cases, first symptoms of anaphylaxis developed ≥30min after immunization. In 60% (15/25) of cases, symptoms resolved ≤60min of presentation. Intramuscular adrenaline was administered in 90% (18/25) of cases. All cases made a full recovery with no sequelae identified. ConclusionThis comprehensive case series of pediatric anaphylaxis as an AEFI identified that diagnostic criteria are useful when applied to a passive vaccine surveillance system when adequate clinical information is available. Anaphylaxis as an AEFI is rare and usually begins within 30min of vaccination. However, healthcare professionals and vaccinees/parents should be aware that onset of anaphylaxis can be delayed beyond 30min following immunization and that medical attention should be sought promptly if anaphylaxis is suspected.

Food-induced anaphylaxis: Clinical highlights and knowledge gaps

An infant was born at full term after a normal first pregnancy with no family history of allergic disease. At six months of age, he developed atopic dermatitis. He was diagnosed to be allergic to peanut and egg proteins, with a strongly positive skin prick test reactivity of >10 mm and >12 mm respectively, although he never had a known exposure to either food. He was prescribed an epinephrine autoinjector, and his parents were advised to avoid products containing peanut or egg. At three years of age, he was brought to the emergency department with generalized hives, swelling of his lips and eyelids, and wheezing immediately after he had eaten candy that had a pre-cautionary label of ‘may contain peanuts’. He was treated with intramuscular epinephrine, oral antihistamine, oral steroids and an inhaled short-acting β2-agonist with good response. The child was discharged after 4 h of observation. The treating physician verified that the family had an epinephrine autoinjector and were aware of the importance of allergen avoidance. LEARNING POINTS Adverse reactions to foods include nonimmune (food intolerances) and immune-mediated hypersensitivity reactions (food allergies). It is crucial to establish the presence of an immunoglobulin E (IgE)-mediated food allergy because this may present as anaphylaxis (1). Anaphylaxis is a severe, life-threatening generalized hypersensitivity reaction (2) accounting for 100 to 125 deaths/year in the United States (3). The overall incidence rate of anaphylaxis is 49.8 per 100,000 person-years, and foods, mainly peanuts and nuts, continue to be major inciting agents (33.2% of reactions [4]). Recently in Canada, it was estimated that peanut allergy affects 1.68% of children (5). A 2011 CPSP survey (6) involving 114 allergists and 613 nonallergists, demonstrated substantial disparities between these two groups regarding the management of food-induced anaphylaxis. The survey also revealed the underuse of epinephrine for severe reactions. Clinically, IgE-mediated food allergy usually presents within seconds to 2 h after exposure (7,8). Anaphylaxis reactions involve several organ systems, including: ○ the skin (80% to 90%): urticaria, pruritus, flushing or angioedema ○ respiratory tract (70%): stridor, breathing difficulties or wheezing ○ gastrointestinal tract (30% to 45%): vomiting and abdominal pain ○ cardiovascular (10% to 45%): mainly loss of blood pressure ○ central nervous system (10% to 15%): mainly loss of consciousness (9). The diagnosis of an IgE-mediated food allergy requires corroboration of the patient’s clinical history with appropriate confirmatory tests, including skin prick tests, food-specific IgE levels and food challenges, as shown in Table 1. TABLE 1 Prompt administration of intramuscular doses of epinephrine remains the gold standard. ○ More rapid absorption and higher plasma concentration have been shown with intramuscular administration, compared with subcutaneous administration of epinephrine. Auto-injectors such as Epipen and Epipen Jr (Mylan Inc, USA), and Twinject (Shionogi Pharma Inc, USA) should always be prescribed for those with a known anaphylactic trigger and must be self-carried at all times (2). ○ Delay in the administration of epinephrine is associated with poor outcome, and the benefits of epinephrine use far outweigh the risks in otherwise healthy individuals (10). Following administration of epinephrine, all patients should be transported to a medical facility because they may require additional treatments such as oxygen, inhaled β2-agonist, intravenous fluid and corticosteroids. H1 and H2 histamine antagonists are considered to be second-line treatments for anaphylaxis (2). Because a biphasic reaction can occur from 1 h to 72 h after initial recovery in up to 20% of anaphylactic cases, there should be a 4 h to 6 h postanaphylactic observation period that can be extended for patients exhibiting severe or refractory symptoms (2). Patients with food allergies and their families should be instructed to diligently avoid foods with potential allergens by carefully reading food labels on prepackaged foods and inquiring about ingredients when eating outside one’s home (11). The use of an identifying tag indicating the presence of a food allergy, such as the MedicAlert bracelet, should be considered.

Perspectives on Anaphylaxis Epidemiology in the United States with New Data and Analyses

Anaphylaxis incidence rates and time trends in the United States have been reported using different data sources and selection methods. Larger studies using diagnostic coding have inherent limitations in sensitivity and specificity. In contrast, smaller studies using chart reviews, including reports from single institutions, have better case characterization but suffer from reduced external validity due to their restricted nature. Increasing anaphylaxis hospitalization rates since the 1990s have been reported abroad. However, we report no significant overall increase in the United States. There have been several reports of increasing anaphylaxis rates in northern populations in the United States, especially in younger people, lending support to the suggestion that higher anaphylaxis rates occur at higher latitudes. We analyzed anaphylaxis hospitalization rates in comparably sized northern (New York) and southern (Florida) states and found significant time trend differences based on age. This suggests that the relationship of latitude to anaphylaxis incidence is complex.

Anaphylaxis epidemiology in patients with and patients without asthma: A United Kingdom database review

There are currently limited data regarding the epidemiology of anaphylaxis. To estimate the incidence of anaphylaxis from all causes, to explore the variety of diagnoses that may predispose to an anaphylactic episode, and to estimate the rate of recurrence of anaphylaxis in patients with no asthma, nonsevere asthma, and severe asthma. The Health Improvement Network database provided data on individuals 10 to 79 years old who had been enrolled for at least 1 year with a general practitioner in the United Kingdom and had at least 1 health contact in the year before entering the study. Anaphylaxis incidence rates (per 100,000 person-years) were 21.28 (95% CI, 17.64-25.44) and 50.45 (95% CI, 44.67-56.76) in the no asthma and overall asthma cohorts, respectively. Risk of anaphylaxis was greater in the nonsevere asthma (relative risk, 2.07; 95% CI, 1.65-2.60) and severe asthma (relative risk, 3.29; 95% CI, 2.47-3.47) subgroups compared with the no asthma cohort. The incidence rate of anaphylaxis was higher in women than men (22.65 vs 19.56 per 100,000 person-years). Within the overall asthma population, patients at significantly increased risk of anaphylaxis included those with allergic rhinitis or atopic dermatitis, and current users of antihistamines, oral steroids, or antibiotics (compared with nonusers). Drug and food allergies were the most common known causes of anaphylaxis. Patients with asthma have a greater risk of anaphylaxis than those without asthma, and the risk is greater in severe than nonsevere asthma. Women are at higher risk of anaphylaxis than men, especially those with severe asthma.

Epidemiology of anaphylaxis in Olmsted County: A population-based study

Background: Awareness of the clinical features of anaphylaxis and its causative triggers is important if recurrent episodes are to be avoided. The incidence of anaphylaxis in the general population is often underreported, and epidemiologic studies are few. Because an accurate profile of anaphylaxis could heighten awareness of this problem, we investigated the epidemiology of anaphylaxis in the general population of Olmsted County, Minn. Objective: The purpose of this study was to describe the epidemiology of anaphylaxis in Olmsted County residents from 1983 through 1987. Methods: This was a retrospective population-based cohort study. The medical records of 1255 Olmsted County residents identified by computer-linked, medical diagnostic indices (the Rochester Epidemiology Study) were reviewed retrospectively to identify residents whose clinical episodes met the criteria for anaphylaxis. We determined the incidence and rate of occurrence of anaphylaxis, rate of recurrence, prevalence of atopy, cause of anaphylaxis, frequency of referral to an allergy specialist, hospital admission rate, and case-fatality rate. Results: There were 133 residents who experienced 154 anaphylactic episodes during the 5-year period: 116 residents had 1 episode of anaphylaxis, 13 residents had 2 episodes, and 4 residents had 3 episodes. The anaphylaxis occurrence rate was 30 per 100,000 person-years (95% confidence interval, 25-35). There were 110 residents who had a first lifetime episode of anaphylaxis (that was medically evaluated) during the years 1983 to 1987. The average annual incidence rate of anaphylaxis was 21 per 100,000 person-years (95% confidence interval, 17-25). Atopy was present in 53% of the cohort, and allergy consultation was obtained in 52%. A suspect allergen was identified in 68% of the cohort, most frequently a food, medication, or insect sting. The hospitalization rate was 7%, and 1 patient died. Conclusion: The incidence of anaphylaxis is less than 1%, and death rarely occurs. People with atopy experience anaphylaxis more frequently than people without atopy. Anaphylaxis frequently is not recognized by patients and physicians. (J Allergy Clin Immunol 1999;104:452-6.)