Differences in Self-Reported Food Allergy and Food-Associated Anaphylaxis by Race and Ethnicity Among SAPPHIRE Cohort Participants.

BACKGROUND: Although food allergies are considered common, relatively little is known about disparities in food allergy by race in the United States. OBJECTIVE: To evaluate differences in reported food allergy and food-associated anaphylaxis among individuals enrolled in a longitudinal cohort study from metropolitan Detroit, Michigan. METHODS: Participants in the Study of Asthma Phenotypes and Pharmacogenomic Interactions by Race-Ethnicity (SAPPHIRE) were asked about food allergies, including the inciting food and associated symptoms. Individuals were considered to have food-associated anaphylaxis if symptoms coincided with established clinical criteria. Logistic regression was used to assess whether race difference persisted after adjusting for and stratifying by potential confounders. African genetic ancestry was individually estimated among African American SAPPHIRE participants to assess whether ancestry was associated with food allergy. RESULTS: Within the SAPPHIRE cohort, African American participants were significantly more likely to report food allergy (26.1% vs 17%; P = 3.47 × 10-18) and have food-associated anaphylactic symptoms (12.7% vs 7%; P = 4.65 × 10-14) when compared with European American participants. Allergy to seafood accounted for the largest difference (13.1% vs 4.6%; P = 1.38 × 10-31). Differences in food allergy by race persisted after adjusting for potential confounders including asthma status. Among African American participants, the proportion of African ancestry was not associated with any outcome evaluated. CONCLUSION: Compared with European Americans, African Americans appear to be at higher risk for developing food allergy and food-associated anaphylaxis, particularly with regard to seafood allergy. The lack of association with genetic ancestry suggests that socioenvironmental determinants may play a role in these disparities.

Improving Methods of Identifying Anaphylaxis for Medical Product Safety Surveillance Using Natural Language Processing and Machine Learning.

We sought to determine whether machine learning and natural language processing (NLP) applied to electronic medical records could improve performance of automated health-care claims-based algorithms to identify anaphylaxis events using data on 516 patients with outpatient, emergency department, or inpatient anaphylaxis diagnosis codes during 2015-2019 in 2 integrated health-care institutions in the Northwest United States. We used one site's manually reviewed gold-standard outcomes data for model development and the other's for external validation based on cross-validated area under the receiver operating characteristic curve (AUC), positive predictive value (PPV), and sensitivity. In the development site 154 (64%) of 239 potential events met adjudication criteria for anaphylaxis compared with 180 (65%) of 277 in the validation site. Logistic regression models using only structured claims data achieved a cross-validated AUC of 0.58 (95% CI: 0.54, 0.63). Machine learning improved cross-validated AUC to 0.62 (0.58, 0.66); incorporating NLP-derived covariates further increased cross-validated AUCs to 0.70 (0.66, 0.75) in development and 0.67 (0.63, 0.71) in external validation data. A classification threshold with cross-validated PPV of 79% and cross-validated sensitivity of 66% in development data had cross-validated PPV of 78% and cross-validated sensitivity of 56% in external data. Machine learning and NLP-derived data improved identification of validated anaphylaxis events.

Anaphylaxis across Europe: are pollen food syndrome and lipid transfer protein allergy so far apart?

PURPOSE OF REVIEW: Traditionally pollen-food syndrome (PFS) is considered to be a mild cross-reacting food allergy affecting only Northern Europe, with lipid transfer protein (LTP) allergy being more severe and mainly occurring in Southern Europe. This review seeks to update the reader on both types of plant food allergy and to determine whether the stereotypical presentations of these plant food allergies remain the same, with a particular focus on reaction severity. RECENT FINDINGS: Recent findings suggest that both these types of plant food allergy occur in children and adults. Although it is true that PFS allergy is more prevalent in Northern Europe and LTP allergy is more well known in Southern Europe, these conditions are not hidebound by geography, and the increasing spread and allergenicity of pollen due to global warming continues to change their presentation. Both conditions have a spectrum of symptom severity, with PFS sometimes presenting with more severe symptoms, including anaphylaxis and LTP allergy with milder reactions. SUMMARY: It is important to consider that in many parts of Europe, reactions to plant foods, especially fruits or vegetables, could be mediated either by pollen cross-reactivity or primary sensitization to LTP allergens. All those presenting with symptoms to plant foods will benefit from a detailed clinical history and appropriate tests so that an accurate diagnosis can be made, and correct management implemented.

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.

Estimating Baseline Incidence of Conditions Potentially Associated with Vaccine Adverse Events: a Call for Surveillance System Using the Korean National Health Insurance Claims Data.

BACKGROUND: Vaccines against coronavirus disease 2019 (COVID-19) are raising concerns about vaccine safety, particularly in the context of large-scale immunization. To address public concerns, we measured the baseline incidence rates of major conditions potentially related to vaccine-related adverse events (VAEs). We aimed to provide a basis for evaluating VAEs and verifying causality. METHODS: Conditions of interest were selected from the US Vaccine Adverse Event Reporting System Table of Reportable Events and a recent report from a European consortium on vaccine surveillance. We used the National Health Insurance Service database in Korea to identify the monthly numbers of cases with these conditions. Data from January 2006 to June 2020 were included. Prediction models were constructed from the observed incidences using an autoregressive integrated moving average. We predicted the incidences of the conditions and their respective 95% confidence intervals (CIs) for January through December 2021. In addition, subgroup analysis for the expected vaccination population was conducted. RESULTS: Mean values (95% CIs) of the predicted monthly incidence of vasovagal syncope, anaphylaxis, brachial neuritis, acute disseminated encephalomyelitis, Bell's palsy, Guillain-Barré syndrome, encephalopathy, optic neuritis, transverse myelitis, immune thrombocytopenic purpura, and systemic lupus erythematosus in 2021 were 23.89 (19.81-27.98), 4.72 (3.83-5.61), 57.62 (51.37-63.88), 0.03 (0.01-0.04), 8.58 (7.90-9.26), 0.26 (0.18-0.34), 2.13 (1.42-2.83), 1.65 (1.17-2.13), 0.19 (0.14-0.25), 0.75 (0.61-0.90), and 3.40 (2.79-4.01) cases per 100,000 respectively. The majority of the conditions showed an increasing trend with seasonal variations in their incidences. CONCLUSION: We measured the incidence of a total of 11 conditions that could potentially be associated with VAEs to predict the monthly incidence in 2021. In Korea, conditions that could potentially be related to VAEs occur on a regular basis, and an increasing trend is observed with seasonality.

Identification and Validation of Anaphylaxis Using Electronic Health Data in a Population-based Setting.

BACKGROUND: Anaphylaxis is a life-threatening allergic reaction that is difficult to identify accurately with administrative data. We conducted a population-based validation study to assess the accuracy of ICD-10 diagnosis codes for anaphylaxis in outpatient, emergency department, and inpatient settings. METHODS: In an integrated healthcare system in Washington State, we obtained medical records from healthcare encounters with anaphylaxis diagnosis codes (potential events) from October 2015 to December 2018. To capture events missed by anaphylaxis diagnosis codes, we also obtained records on a sample of serious allergic and drug reactions. Two physicians determined whether potential events met established clinical criteria for anaphylaxis (validated events). RESULTS: Out of 239 potential events with anaphylaxis diagnosis codes, the overall positive predictive value (PPV) for validated events was 64% (95% CI = 58 to 70). The PPV decreased with increasing age. Common precipitants for anaphylaxis were food (39%), medications (35%), and insect bite or sting (12%). The sensitivity of emergency department and inpatient anaphylaxis diagnosis codes for all validated events was 58% (95% CI = 51 to 65), but sensitivity increased to 95% (95% CI = 74 to 99) when outpatient diagnosis codes were included. Using information from all validated events and sampling weights, the incidence rate for anaphylaxis was 3.6 events per 10,000 person-years (95% CI = 3.1 to 4.0). CONCLUSIONS: In this population-based setting, ICD-10 diagnosis codes for anaphylaxis from emergency department and inpatient settings had moderate PPV and sensitivity for validated events. These findings have implications for epidemiologic studies that seek to estimate risks of anaphylaxis using electronic health data.

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.

Can patients with oral allergy syndrome be at risk of anaphylaxis?

PURPOSE OF REVIEW: Oral allergy syndrome, also known as pollen-food syndrome (PFS), is a condition usually associated with adults and characterized by mild transient oropharyngeal symptoms. The purpose of this review is to determine whether systemic or anaphylactic reactions do occur and if so, who is affected and what are the triggers. RECENT FINDINGS: An increasing number of studies demonstrate that PFS occurs all age groups, and a significant number of affected adults do experience systemic and anaphylactic reactions. The upsurge in the adoption of vegan lifestyles, increase in consumption of fruits and vegetables including smoothies and juices, and use of plant foods in nutritional or body-building supplements, could exacerbate this. Changes in pollen and pollution levels, cofactors and sensitization to other plant food allergens may also be involved. SUMMARY: While the majority of those with PFS will continue to experience mild symptoms, all individuals should be properly advised regarding the dangers of concentrated or unusual forms of plant food allergens such as smoothies, juices, soy/nut milks and nutritional supplements. Further well characterized studies are needed to determine risk factors for severe reactions, and sensitization patterns to pollens and plant food allergens.

Anaphylaxis - Lessons learnt when East meets West.

The rapidly increasing prevalence of allergic disorders over the past 2 decades highlights the need to understand the epidemiology of anaphylaxis. In Europe, the United States, and Australia, the incidence of anaphylaxis is estimated to be between 60 and 950 cases per 100 000 population, with a lifetime prevalence of anaphylaxis of 0.05%-2%. The incidence appears to be increasing over time. Although the existing Asian literature is heterogeneous and limited by under-reporting, it also suggests a similar increasing trend in anaphylaxis incidence in Asia. Anaphylaxis triggers in Asia, such as the predominance of shellfish and wheat in older children and adolescents, differ from those seen in Western populations. Triggers unique to Asia such as traditional Chinese medications, galacto-oligosaccharides, and food delicacies have also been reported. Low usage of adrenaline as first-line treatment of anaphylaxis is evident across all countries and is particularly concerning. There is a need to establish prospective, standardized protocols for anaphylaxis data collection and reporting, to enhance the collective understanding of anaphylaxis and its burden, gaps in management and to identify areas for future research and intervention in each region. Understanding of the underlying reasons explaining the difference between East and West will facilitate future primary preventive strategies.

Safety profile of traditional Chinese herbal injection: An analysis of a spontaneous reporting system in China.

PURPOSE: Although a series of serious adverse events have continually raised concerns about the potential toxicity of traditional Chinese medicine injections (TCM injections), studies on this subject are still sparse. We conducted a descriptive analysis of a spontaneous reporting system in China to describe the safety profile of TCM injections. METHODS: The safety profile of TCM injections is described by descriptive analysis of 559 066 adverse reports collected from Guangdong Provincial Center for adverse drug reaction (ADR) Monitoring in China during 2003 to 2017. RESULTS: The percentage of new or serious ADRs of TCM injections is much higher than average percentage of China's spontaneous reporting system (SRS) as a whole (48.70% vs <25%). Compared with conventional injections, TCM injections have a slightly lower percentage of serious ADRs (6.02% vs 6.72%) and much higher percentage of unknown (new) ADRs (46.74% vs 24.13%). The gender and age distribution for TCM injections are similar to conventional injections. The reporting rates of ADRs increased with age. Anaphylactic shock and anaphylactoid reaction are high-risk ADRs for TCM injections and, anaphylactic shock is ranked number 1 in causing deaths (50.00%). CONCLUSIONS: There are some differences and similarities on the safety profile between TCM injections and conventional injections. TCM injections have higher risk of adverse effects than any other dosage forms of TCM medications and higher percentage of new or serious adverse effects than conventional injections. A lot of work need to be done to clarify the huge amount of potential unknown adverse effects related to TCM injections.

Ferumoxytol for the treatment of iron deficiency anemia.

INTRODUCTION: Ferumoxytol is a superparamagnetic molecule originally developed as a contrast agent for magnetic resonance imaging. Elemental iron is contained within the carbohydrate core and is released slowly after infusion allowing a large dose of iron to be administered in a short period of time. Ferumoxytol, originally approved for iron deficiency in chronic kidney disease, received a broad label for any cause of iron deficiency after oral iron intolerance or in those circumstances when oral iron is ineffective or harmful. Areas covered: The chemistry, pharmacology and pharmacokinetics of ferumoxytol were reviewed. Retrospective, observational, and prospective phase II and III trials were reviewed. When appropriate, comparative safety and efficacy parameters were reported. Differentiation between minor infusion reactions and more severe hypersensitivity reactions that may lead to anaphylaxis is described. Expert commentary: Ferumoxytol is a safe and effective iron formulation providing a means of iron repletion in persons with iron deficiency with or without anemia. Relative to iron sucrose, ferric gluconate, and iron dextran and similar to ferric carboxymaltose and iron isomaltoside, ferumoxytol yields relatively low quantities of labile free iron. Hypersensitivity and anaphylaxis is extremely rare. Hypophosphatemia with ferumoxytol's administration is extremely rare. Optimal strategies for application of ferumoxytol-enhanced imaging and full replacement dosing in a single setting remain to be determined.

Traditional Chinese medicine and drug-induced anaphylaxis: data from the Beijing pharmacovigilance database.

Background Traditional Chinese medicine (TCM) is one of the major triggers for drug-induced anaphylaxis (DIA). Objective We aimed to use the Beijing pharmacovigilance database (BPD) to analyze TCM-induced DIAs in Beijing, China. Setting Drug allergy case reports from the BPD provided by the Beijing Center for Adverse Drug Reaction Monitoring. Method Drug allergy cases from January 2004 to December 2014 were adjudicated. DIA triggered by TCMs were analyzed and compared with those triggered by non-TCM drugs by calculating the reported risk ratio (RRR). We also calculated the RRRs based on severe DIA and death outcomes. Main outcome measure TCMs implicated in DIAs were identified and compared with non-TCM drugs. Results TCMs accounted for 1651 (18.2%) of the total 9074 allergic cases, in which 84.4% (1393/1651) were triggered by injections. Of the TCM allergic cases, 8.5% (141) were DIAs and 7.3% (120) were severe DIAs, and three patients died from injections. The RRR between TCMs and non-TCM-induced DIAs was 0.63. When anaphylactic cases were compared between TCMs to the top four non-TCM drug triggers, RRRs were 0.73 (95% CI 0.61-0.87) for antibiotics, 0.36 (95% CI 0.29-0.44) for radiocontrast agents, 0.55 (95% CI 0.43-0.68) for chemotherapeutics, and 0.29 (95% CI 0.23-0.37) for biologics. Compared to TCM oral or topic formulations, TCM injections had higher RRRs in each of the above comparisons. Conclusion TCM was associated with a decreased risk of DIA compared to non-TCM drugs in drug allergy cases, and the risk was higher for TCM injections.

The safety of live attenuated influenza vaccine in children and adolescents 2 through 17 years of age: A Vaccine Safety Datalink study.

PURPOSE: To evaluate the safety of live attenuated influenza vaccine (LAIV) in children 2 through 17 years of age. METHODS: The study was conducted in 6 large integrated health care organizations participating in the Vaccine Safety Datalink (VSD). Trivalent LAIV safety was assessed in children who received LAIV between September 1, 2003 and March 31, 2013. Eighteen pre-specified adverse event groups were studied, including allergic, autoimmune, neurologic, respiratory, and infectious conditions. Incident rate ratios (IRRs) were calculated for each adverse event, using self-controlled case series analyses. For adverse events with a statistically significant increase in risk, or an IRR > 2.0 regardless of statistical significance, manual medical record review was performed to confirm case status. RESULTS: During the study period, 396 173 children received 590 018 doses of LAIV. For 13 adverse event groups, there was no significant increased risk of adverse events following LAIV. Five adverse event groups (anaphylaxis, syncope, Stevens-Johnson syndrome, adverse effect of drug, and respiratory failure) met criteria for manual medical record review. After review to confirm cases, 2 adverse event groups remained significantly associated with LAIV: anaphylaxis and syncope. One confirmed case of anaphylaxis was observed following LAIV, a rate of 1.7 per million LAIV doses. Five confirmed cases of syncope were observed, a rate of 8.5 per million doses. CONCLUSIONS: In a study of trivalent LAIV safety in a large cohort of children, few serious adverse events were detected. Anaphylaxis and syncope occurred following LAIV, although rarely. These data provide reassurance regarding continued LAIV use.

Reactions of Buckwheat-Hypersensitive Patients during Oral Food Challenge Are Rare, but Often Anaphylactic.

BACKGROUND: Buckwheat (BW) is a common cause of life-threatening allergy in Asia. Few have examined oral food challenges (OFCs) using BW. We here describe the OFC outcomes for the diagnosis or confirmation of tolerance acquisition and clarify risk factors for positive OFCs. METHODS: Between July 2005 and March 2014, we retrospectively reviewed data from children who underwent OFCs using 3,072 mg of BW protein at Sagamihara National Hospital. Children were suspected of having BW allergy because of positive results for BW-specific IgE or because they had been previously diagnosed with BW allergy owing to immediate reactions to BW. RESULTS: Of 476 such patients, we analyzed 419 aged 1-17 years (median age 6.7 years). Forty-four (10.5%) reacted to the BW OFC and 24 (54.5%) experienced anaphylaxis. Among patients with suspected BW allergies (n = 369), 30 (8.1%) reacted to OFC. However, among patients with definitive BW allergies (n = 50) who underwent OFCs a median of 7.0 years after their last immediate reaction, 14 (28.0%) reacted to OFC. Among 12 patients with past anaphylactic reactions to BW, 8 exhibited tolerance to BW. A history of immediate reaction to BW and high BW-specific IgE levels were significant risk factors for a positive OFC. CONCLUSIONS: BW allergies are rare among children suspected of having BW allergies due to positivity for BW-specific IgE. Most children with definitive BW allergies can tolerate BW, even after anaphylactic reactions. Nevertheless, careful observation is needed when performing BW OFCs, considering the high incidence of anaphylactic reactions.

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.

Pre-hospital treatment of bee and wasp induced anaphylactic reactions: a retrospective study.

BACKGROUND: Bee and wasp stings are among the most common triggers of anaphylaxis in adults representing around 20% of fatal anaphylaxis from any cause. Data of pre-hospital treatment of bee and wasp induced anaphylactic reactions are sparse. This study aimed to estimate the incidence of bee and wasp induced anaphylactic reactions, the severity of the reactions and to correlate the pre-hospital treatment with the severity of the anaphylactic reaction. METHODS: Retrospective and descriptive study based on data from the Mobile Emergency Care Units (MECUs) in the Region of Southern Denmark (2008 only for Odense and 2009-2014 for the whole region). Discharge summaries with diagnosis related to anaphylaxis according to the International Classification of Diseases 10 (ICD-10) were reviewed to identify bee and wasp induced anaphylactic reactions. The severity of the anaphylactic reaction was assessed according to Sampson's severity score and Mueller's severity score. Treatment was evaluated in relation to administration of adrenaline, glucocorticoids and antihistamine. RESULTS: We identified 273 cases (Odense 2008 n = 14 and Region of Southern Denmark 2009-2014 n = 259) of bee and wasp induced anaphylaxis. The Incidence Rate was estimated to 35.8 cases per 1,000,000 person year (95% CI 25.9-48.2) in the Region of Southern Denmark during 2009-2014. According to Sampson's severity score, 65% (n = 177) of the cases were graded as moderate to severe anaphylaxis (grade 3-5). Almost one third of cases could not be graded according to Mueller's severity score. Adrenaline was administrated in 54% (96/177) of cases with moderate to severe anaphylaxis according to Sampson's severity score, compared to 88% receiving intravenous glucocorticoids (p < 0.001) and 91% receiving intravenous antihistamines (p < 0.001). Even in severe anaphylaxis (grade 5) adrenaline was administered in only 80% of the cases. CONCLUSION: Treatment with adrenaline is not administered in accordance with international guidelines. However, making an assessment of the severity of the anaphylactic reaction is difficult in retrospective studies.

The European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI): A paediatric assessment.

BACKGROUND: Safety data on 'real-life' allergen immunotherapy (AIT) in children and adolescents is usually extrapolated from studies in adults. METHODS: Patients aged 18 or under initiating aeroallergen AIT were evaluated in a prospective European survey. Patient profiles and systemic reactions (SRs) were recorded. Descriptive, univariate and multivariate analyses were used to identify risk factors for SRs. RESULTS: A total of 1563 patients (mean ± SD age: 11.7 ± 3.9 years; rhinitis: 93.7%; asthma: 61.5%; polysensitization: 62.5%) and 1578 courses of AIT were assessed. Single-allergen AIT was administered in 89.5% of cases (n = 1412; mites: 49%; grass pollen: 25.8%; tree pollen: 8.7%; Alternaria: 4.6%; dander: 0.8%; weed pollen: 0.6%). Subcutaneous AIT (SCIT) was used in 71.4% (n = 1127) of the treatments, including 574 (50.9%) with natural extracts. Sublingual AIT (SLIT) was used for the remaining 451 treatments (drops: 73.8%; tablets: 26.2%). The mean ± SD follow-up period was 12.9 ± 3.3 months. The estimated total number of doses was 19,669 for SCIT and 131,550 for SLIT. Twenty-four patients (1.53%) experienced 29 SRs. Respiratory (55.7%) and skin symptoms (37.9%) were most frequent. Anaphylaxis was diagnosed in 3 SRs (10.3%), and adrenaline was administered in 2 of these cases. In a univariate analysis, the risk of SRs was lower in mite-sensitized patients and higher in cases of pollen polysensitization (>3), grass pollen extracts and the use of natural extracts (vs. allergoids). CONCLUSIONS: In a real-life paediatric setting, AIT is safe. SRs are infrequent and generally not severe. Pollen polysensitization, grass pollen extracts and natural extracts (vs. allergoids) were risk factors for AIT-associated SRs.

Anaphylaxis.

Anaphylaxis is an acute, systemic reaction mediated by immunoglobulin E hypersensitivity. Release of bioactive factors causes vasodilation and bronchiole constriction that can lead to hypotensive shock and asphyxiation. Differential diagnosis includes acute asthma, localized angioedema, syncope, and anxiety/panic attacks. Diagnostic tests lack specificity. Clinical diagnosis is based on demonstration of specific airway or cardiovascular compromise within proximity of allergen exposure. Treatment includes epinephrine, antihistamines, fluid resuscitation, and airway management. Prevention focuses on awareness/avoidance of triggers, implementation of personalized action plans, as well as immune modulation by desensitization in a closely controlled setting where available.