International consensus on (ICON) anaphylaxis

Cashew nut allergy in Singaporean children

Background

There has been an increasing trend of nut allergies in Singapore.

Objective

The aim of this study was to review the clinical characteristics of children with cashew nut allergy.

Methods

A retrospective analysis was conducted in a tertiary paediatric referral centre in Singapore from 2008 to 2015. A total of 99 subjects with positive specific IgE (≥0.35 IU/L) to cashew nut were identified. Clinical features including demographics, clinical reaction to cashew nut, associations with other nuts and test specific measurements were recorded.

Results

The results showed that cutaneous symptoms (71.2%) were the most common allergic manifestations. Anaphylaxis occurred in 3.8% of children. In addition, all cashew nut allergic subjects were cross-reactive (either sensitized or allergic) to pistachio. Cross-reactivity rate with peanuts was 53.8%. There was a strong prevalence of atopy among cashew nut allergic subjects.

Conclusion

In conclusion, cashew nut allergy is a significant tree nut allergy in Singapore.

Anaphylaxis in the 21st century: phenotypes, endotypes, and biomarkers

Anaphylaxis is the most serious of all allergic reactions and can be fatal. The diagnosis is frequently delayed, and misdiagnosis often occurs with asthma or urticaria. Biomarkers such as tryptase are not routinely checked, and appropriate treatment with epinephrine is not administered in a majority of cases, increasing the risk of poor outcomes. The objective of this review is to provide a better understanding of the pathophysiology of anaphylaxis with a description of phenotypes, endotypes, and biomarkers available in both the clinical and research settings. Expanding knowledge with regard to the presentation, causes, and triggers for anaphylaxis among health care providers will improve its diagnosis and management, increase patient safety, and decrease morbidity and mortality.

Food-induced anaphylaxis in infants and children

BACKGROUND

Recent recommendations to introduce peanut products to infants for peanut allergy prevention requires a focused assessment of infant anaphylaxis.

OBJECTIVE

This study describes the symptomatology of food-induced anaphylaxis (FIA) in infants (<12 months) compared with older pediatric cohorts.

METHODS

Retrospective review between June 2015 and June 2017 of children presenting with FIA at a large urban children's hospital emergency department (ED).

RESULTS

A total of 357 cases of FIA were evaluated: 47 in infants (<12 months), 43 in toddlers (12-24 months), 96 in young children (2-6 years), and 171 in school-aged children (>6 years). Infants presented with gastrointestinal (GI) involvement more frequently than any other age group (89% vs 63% [P = .003], 60% [P < .001], and 58% [P < .001]). Additionally, infants and young children presented with skin involvement more frequently than school-aged children (94% and 91% vs 62% [P < .001]). Respiratory symptoms were more common in older cohorts (17% in infants vs 44% in young children [P < .001] and 54% in school-aged children [P < .001]). Egg and cow's milk were more common causes of FIA in infants compared with school-aged children (egg, 38% vs 1% [P < .001]; milk, 17% vs 7% [P = .03]). Only 21% of infants with FIA had eczema, and 36% had a history of food allergy.

CONCLUSION

Infants with FIA primarily presented with GI and skin manifestations. Egg was the most common food trigger in infants. Most infants with FIA did not have eczema or a history of food allergy.

Specific questionnaire detects a high incidence of intra-operative hypersensitivity reactions

OBJECTIVE

To assess the incidence of intra-operative immediate hypersensitivity reactions and anaphylaxis.

METHODS

A cross-sectional observational study was conducted at the Department of Anesthesiology, University of São Paulo School of Medicine, Hospital das Clínicas, São Paulo, Brazil, from January to December 2010. We developed a specific questionnaire to be completed by anesthesiologists. This tool included questions about hypersensitivity reactions during anesthesia and provided treatments. We included patients with clinical signs compatible with immediate hypersensitivity reactions. Hhypersensitivity reactions were categorized according to severity (grades I-V). American Society of Anesthesiologists physical status classification (ASA 1-6) was analyzed and associated with the severity of hypersensitivity reactions.

RESULTS

In 2010, 21,464 surgeries were performed under general anesthesia. Anesthesiologists answered questionnaires on 5,414 procedures (25.2%). Sixty cases of intra-operative hypersensitivity reactions were reported. The majority patients (45, 75%) had hypersensitivity reactions grade I reactions (incidence of 27.9:10,000). Fifteen patients (25%) had grade II, III or IV reactions (intra-operative anaphylaxis) (incidence of 7:10,000). No patients had grade V reactions. Thirty patients (50%) were classified as ASA 1. The frequency of cardiovascular shock was higher in patients classified as ASA 3 than in patients classified as ASA 1 or ASA 2. Epinephrine was administered in 20% of patients with grade III hypersensitivity reactions and in 50% of patients with grade II hypersensitivity reactions.

CONCLUSIONS

The majority of patients had hypersensitivity reactions grade I reactions; however, the incidence of intra-operative anaphylaxis was higher than that previously reported in the literature. Patients with ASA 3 had more severe anaphylaxis; however, the use of epinephrine was not prescribed in all of these cases. Allergists and anesthesiologists should implement preventive measures to reduce the occurrence of anaphylaxis.

Do Corticosteroids Prevent Biphasic Anaphylaxis?

Anaphylaxis is a severe hypersensitivity reaction that is rapid in onset and can result in death. The pattern of an anaphylactic reaction can be uniphasic (or monophasic), biphasic (also called delayed or late phase), or refractory in nature. The most widely cited definition of biphasic anaphylaxis is a recurrence of anaphylactic symptoms after initial resolution despite no further exposure to the trigger. Corticosteroids are thought by some to prevent the development of biphasic symptoms and, therefore, commonly used in the emergency treatment of anaphylaxis but this has not been systemtically analyzed. In this review, Ovid MEDLINE, Ovid EMBASE, Web of Science, and Scopus were searched for articles using "anaphylaxis" combined with the key terms "biphasic" and/or "corticosteroids" and/or "epinephrine." A total of 31 appropriate studies were identified. Biphasic anaphylactic reactions are more likely to occur in moderate to severe anaphylaxis or when anaphylaxis is not treated with timely epinephrine. Because of the potential detrimental adverse effects of corticosteroids and lack of compelling evidence demonstrating an effective role in reducing anaphylaxis severity or preventing biphasic anaphylaxis, we do not advocate for their routine use in anaphylaxis.

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.

Knowledge of allergies and performance in epinephrine auto-injector use: a controlled intervention in preschool teachers

Epinephrine auto-injectors are used for first aid in anaphylactic emergencies by non-healthcare professionals, e.g., (pre-)school teachers. We developed an education session for preschool teachers addressing allergies, anaphylactic emergencies, and administering auto-injectors. We assessed their attitudes and knowledge in allergies and anaphylactic emergency by a questionnaire and monitored their practical performance in administering auto-injectors before the education session, directly after, and 4-12 weeks after the session. From 75 teachers giving their consent to participate, 81% had children with allergies under their supervision and 3% had already administered medication from an available rescue kit. The knowledge of triggers of allergies increased from 9 to 55% directly and to 33% 4-12 weeks after the session (both p < 0.001, compared to baseline). Directly after the session, the number of teachers who felt well-prepared for an anaphylactic emergency rose from 11 to 88%, which decreased to 79% 4-12 weeks thereafter (each p < 0.001). The number of auto-injector administrations without any drug-related problems increased from 3 to 35% directly after the session and shrunk to 16% 4-12 weeks afterwards (both p < 0.025).

CONCLUSION

A single education session substantially improved preschool teachers' attitudes and knowledge in allergies and anaphylactic emergencies. Additionally, their practical performance in auto-injector administration increased. What is Known: • Food allergies are increasing among children. • The knowledge about allergies and anaphylactic emergencies is poor. What is New: • The proportion of teachers who felt well-prepared for an anaphylactic emergency increased after a single education session. • The proportion of auto-injector administrations without any drug-related problems additionally increased due to an education session.

Epinephrine in Severe Allergic Reactions: The European Anaphylaxis Register

BACKGROUND

Current guidelines recommend intramuscular administration of epinephrine as the first-line drug for the emergency treatment of severe allergic reactions (anaphylaxis), but no randomized trial evidence supports this consensus.

OBJECTIVE

We aimed to assess anaphylaxis treatment practices over 10 years, covering several European regions, all allergen sources, and all age groups.

METHODS

The European Anaphylaxis Register tracks elicitors, symptoms, emergency treatment, diagnostic workups, and long-term counseling for anaphylaxis incidents through web-based data entry from tertiary allergy specialists, covering information from the emergency respondent, patient, tertiary referral, and laboratory/clinical test results.

RESULTS

We analyzed 10,184 anaphylaxis incidents. In total, 27.1% of patients treated by a health professional received epinephrine and, in total, 10.5% received a second dose. Successful administration was less frequent in German-speaking countries (minimum 19.6%) than in Greece, France, and Spain (maximum 66.7%). Over the last decade, epinephrine administration from a health professional almost doubled to reach 30.6% in 2015-2017, half of which was applied intramuscularly. A total of 14.7% of lay- or self-treated cases were treated with an autoinjector. Of those without treatment, 22.4% carried a device for administration. No change in successful administration by lay emergency respondents was found over the last 10 years. Of the reaction and patient characteristics analyzed, only clinical severity considerably influenced the likelihood of receiving epinephrine, with 66.9% of successful administrations in near-fatal (grade IV) reactions.

CONCLUSIONS

Despite clear recommendations, only a small proportion of anaphylaxis incidents are treated with epinephrine. We demonstrated a slight increase in treated patients when handled by professionals, but stagnation in lay- or self-treated anaphylaxis. The reaction circumstances, the respondent's professional background, and patient characteristics did not explain which reactions were treated.

Epinephrine auto-injector needle lengths: Can both subcutaneous and periosteal/intraosseous injection be avoided?

BACKGROUND

Epinephrine should be administered intramuscularly in the anterolateral aspect of the thigh. The length of the epinephrine auto-injector (EAI) needle should ensure intramuscular injection.

OBJECTIVE

To discuss suitable EAI needle lengths based on ultrasound measurements related to weight.

METHODS

The skin-to-muscle distance (STMD) and skin-to-bone distance (STBD) were measured by ultrasound in the mid-third of the anterolateral area of the right thigh when applying high pressure (8 lb; high-pressure EAI [HPEAI]) or low pressure (low-pressure EAI [LPEAI]) on the ultrasound probe. The study included 302 children and adolescents and 99 adults. The maximum and minimum STMD and the maximum and minimum STBD were estimated.

RESULTS

Using HPEAIs, the risk of periosteal or intraosseous penetration was 32% in children weighing less than 15 kg. The risk of subcutaneous injection was 12% in adolescents and 33% in adults. With LPEAIs, there was no risk of periosteal or intraosseous injection and the risk of subcutaneous injections in adolescents and adults was lower at 2% and 10%, respectively. A new EAI for injection in small children would have no risk of periosteal or intraosseous injection but would have 71% chance of subcutaneous deposit of epinephrine.

CONCLUSION

Common HPEAIs have a high risk of periosteal or intraosseous penetration in children and subcutaneous injections in overweight and obese adults. LPEAIs have some risk of subcutaneous injection in adults. HPEAIs with 0.1 mg of epinephrine and shorter needles have no risk of periosteal or intraosseous injection but have a high risk of subcutaneous deposit. For adult or overweight or obese patients, HPEAIs and LPEAIs should have longer needles. Future studies should focus on triggering pressures and variations in needle length.

Anaphylaxis management: a survey of school and day care nurses in Lebanon

OBJECTIVE

Children are at a high risk of developing allergic reactions. Since they spend lots of time at the school or day care, the odds of having an allergic event in this setting is high, hence placing the onus of properly managing their event on nurses. In Lebanon, little is known whether a standardised policy for managing allergic and anaphylactic reaction exists, leaving children unsafe and the school personnel liable. Thus, the aim of this study is to describe the current practices in the management of severe allergies and anaphylaxis by Lebanese nurses working in schools and day cares and to explore the perceived need for a protocol to manage anaphylaxis reaction.

METHODS

A cross-sectional survey with nurses working at schools and day cares in Lebanon was conducted.

RESULTS

A total of 59 school and day care nurses participated. Eighteen of the school and day care nurses reported having a written policy describing the management steps. Only 12 had witnessed an anaphylactic event. Of those, 10 reported administering an antihistamine medication orally instead of epinephrine intramuscular. Most respondents (56) believed that a standardised guideline for the management of anaphylaxis was essential, and 9 indicated being hesitant to give the epinephrine intramuscular even in the presence of a policy. Finally, 55 stated the need for training nurses in identifying and managing anaphylaxis as a must.

CONCLUSION

Currently, the management of anaphylaxis reaction in schools and day cares is suboptimal. Hence, there is a need for a standardised nursing guideline and training for nurses in these settings.

Anaphylactic Shock During Pediatric Anesthesia: An Unexpected Reaction to Sevoflurane

During general anesthesia, while muscle relaxants, latex and antibiotics are normally considered as very common causes of anaphylactic reactions, there are no documented cases of anaphylaxis due to inhalational agents. We report the case of a 6-year-old child scheduled for adenotonsillectomy who had an anaphylactic shock reaction due to Sevoflurane. Several allergic tests were performed to detect the trigger. Drugs used during operation were tested on both patient and three matched controls. While controls were negative, the patient displayed a positive reaction to Sevoflurane. To our knowledge, this is the first published report describing an allergic reaction caused by a volatile anesthetic.

Child with Allergies or Allergic Reactions

Incidence of allergic disorders in children has increased significantly over time due to environmental and life-style changes. These include allergic rhinitis, atopic dermatitis, allergic conjunctivitis, food allergies, bronchial asthma, drug allergies, insect bites and anaphylaxis; most being IgE-mediated type 1 hypersensitivity reactions to common environmental and food antigens. Although most of them are self-limiting, they may adversely affect the quality of life and sometimes become life-threatening as well. These conditions are more likely to get underestimated, or over-diagnosed as recurrent infections. Hence a careful history and physical examination by attending pediatrician are necessary to differentiate it from infections. Diagnostic tests have limited value in identifying the inciting allergen. Management includes avoidance of the inciting allergens (if known), combined with symptomatic relief provided by a combination of pharmacological agents, e.g., antihistamines, anticholinergics, chromones, leukotriene-modifying agents, topical and systemic steroids. Further, specialist consultation needs to be sought, for children with recurrent or persistent symptoms. The scope of this manuscript does not include bronchial asthma.

Anaphylaxis triggers in a large tertiary care hospital in Qatar: a retrospective study

BACKGROUND

Anaphylaxis is a serious allergic disease that may lead to death if not immediately recognized and treated. Triggers of anaphylaxis including food, drugs, and insect stings can vary widely. The incidence of anaphylaxis seems to be affected by age, sex, atopy, and geographic location. This study aims to examine the common triggers of anaphylaxis in Qatar.

METHODS

A total of 1068 electronic medical records were audited using power chart system: 446 from the medical coding system of anaphylaxis and 622 from the epinephrine auto-injectors (EAIs) dispensed during January 2012-December 2017.

RESULTS

Of 1068 patients, 574 (53.5%) had anaphylaxis; male to female ratio was 1.2, and 300 patients (77.9%) were less than 10 years old. The common triggers were food (n = 316, 55.0%), insect stings (n = 161, 28.0%), and drugs (n = 103, 17.9%). Common anaphylaxis food triggers were nuts (n = 173, 30.1%), eggs (n = 89, 15.5%), and seafood (n = 72, 12.5%), and common anaphylaxis medication triggers were antibiotics (n = 49, 8.5%) and nonsteroidal anti-inflammatory drugs (n = 30, 5.2%). Interestingly, 135 anaphylactic patients (23.5%) were due to black ant stings. The anaphylaxis triggers varied significantly between children and adults. Among children (less than 10 years), three quarters of the events were triggered by food (223, 74.3%) while among adults (20-55 years), insect stings (n = 59, 43.0%) and drugs (n = 44, 32.0%) were dominant.

DISCUSSION

This is the first national study stratifying anaphylaxis triggers among different age groups in Qatar. This study will serve as a guide for clinical practice in allergy clinics in Qatar and will help to assess future trends of anaphylaxis in Qatar.

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.

IV Brazilian Consensus on Rhinitis - an update on allergic rhinitis

INTRODUCTION

The guidelines on allergic rhinitis aim to update knowledge about the disease and care for affected patients. The initiative called "Allergic Rhinitis and its Impact on Asthma", initially published in 2001 and updated in 2008 and 2010, has been very successful in disseminating information and evidence, as well as providing a classification of severity and proposing a systemized treatment protocol. In order to include the participation of other medical professionals in the treatment of allergic rhinitis, it is important to develop algorithms that accurately indicate what should and can be done regionally.

OBJECTIVE

To update the III Brazilian Consensus on Rhinitis - 2012, with the creation of an algorithm for allergic rhinitis management.

METHODS

We invited 24 experts nominated by the Brazilian Association of Allergy and Immunology, Brazilian Association of Otorhinolaryngology and Head and Neck Surgery and Brazilian Society of Pediatrics to update the 2012 document.

RESULTS

The update of the last Brazilian Consensus on Rhinitis incorporated and adapted the relevant information published in all "Allergic Rhinitis and its Impact on Asthma" Initiative documents to the Brazilian scenario, bringing new concepts such as local allergic rhinitis, new drugs and treatment evaluation methods.

CONCLUSION

A flowchart for allergic rhinitis treatment has been proposed.

Epidemiology of severe anaphylaxis: can we use population-based data to understand anaphylaxis?

PURPOSE OF REVIEW

The observed increase in incidence of allergic disease in many regions over the past 3 decades has intensified interest in understanding the epidemiology of severe allergic reactions. We discuss the issues in collecting and interpreting these data and highlight current deficiencies in the current methods of data gathering.

RECENT FINDINGS

Anaphylaxis, as measured by hospital admission rates, is not uncommon and has increased in the United Kingdom, the United States, Canada, and Australia over the last 10-20 years. All large datasets are hampered by a large proportion of uncoded, 'unspecified' causes of anaphylaxis. Fatal anaphylaxis remains a rare event, but appears to be increasing for medication in Australia, Canada, and the United States. The rate of fatal food anaphylaxis is stable in the United Kingdom and the United States, but has increased in Australia. The age distribution for fatal food anaphylaxis is different to other causes, with data suggesting an age-related predisposition to fatal outcomes in teenagers and adults to the fourth decade of life.

SUMMARY

The increasing rates of food and medication allergy (the latter exacerbated by an ageing population) has significant implications for future fatality trends. An improved ability to accurately gather and analyse population-level anaphylaxis data in a harmonized fashion is required, so as to ultimately minimize risk and improve management.

Predictors of epinephrine dispensing and allergy follow-up after emergency department visit for anaphylaxis

BACKGROUND

National guidelines recommend that patients with anaphylaxis be prescribed an epinephrine auto-injector (EAI) and referred to an allergy/immunology (A/I) specialist.

OBJECTIVE

To evaluate guideline concordance and identify predictors of EAI dispensing and A/I follow-up in patients with anaphylaxis treated in the emergency department (ED).

METHODS

We identified patients seen in the ED for anaphylaxis from 2010 through 2014 from an administrative claims database using an expanded International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm.

RESULTS

Of 7,790 patients identified, 46.5% had an EAI dispensed and 28.8% had A/I follow-up within 1 year after discharge. On multivariable analysis, those 65 years or older (odds ratio [OR] 0.35, 95% confidence interval [CI] 0.30-0.41) and with a medication trigger (OR 0.24, 95% CI 0.21-0.28) had a lower likelihood of EAI dispensing. Those younger than 5 years (OR 2.67, 95% CI 2.15-3.32) and with food (OR 1.40, 95% CI 1.24-1.59) or venom (OR 4.48, 95% CI 3.51-5.72) triggers had a higher likelihood of EAI dispensing. Similarly, for A/I follow-up, the likelihood was lower for age 65 years or older (OR 0.46, 95% CI 0.39-0.54) and medication trigger (OR 0.66, 95% CI 0.56-0.78) and higher for age younger than 5 years (OR 3.15, 95% CI 2.63-3.77) and food trigger (OR 1.39, 95% CI 1.22-1.58).

CONCLUSION

Overall, 46.5% of patients with anaphylaxis in the ED had EAI dispensing and 28.8% had A/I follow-up. Patient age and triggers were associated with likelihood of EAI dispensing and A/I follow-up. Post-ED visit anaphylaxis management can be improved, with the potential to decrease future morbidity and mortality risk.

Australian and New Zealand Anaesthetic Allergy Group Perioperative Anaphylaxis Investigation Guidelines

These guidelines are a consensus document developed by a working party of the Australian and New Zealand Anaesthetic Allergy Group (ANZAAG) to provide an approach to the investigation of perioperative anaphylaxis. They focus primarily on the use of skin testing as it is the investigation with the greatest clinical utility for the identification of the likely causative agent and potentially safer alternatives. The practicalities and process of skin testing, its limitations, and the place of other tests are discussed. These guidelines also address the roles of graded challenge and in vitro testing. The implications of anaphylaxis associated with neuromuscular blocking agents, beta-lactam antibiotics, local anaesthetic agents and chlorhexidine are discussed. Evidence for the recommendations is derived from literature searches using the words skin test, allergy, anaphylaxis, anaesthesia, and each of the individual agents listed in these guidelines. The individual articles were then reviewed for suitability for inclusion in these guidelines. Where evidence was not strong, as is the situation for many perioperative agents, expert consensus from the ANZAAG working party was used. These guidelines are intended for use by specialists involved in the investigation of perioperative allergy. They have been approved following peer review by members of ANZAAG and are available on the ANZAAG website: http://www.anzaag.com/anaphylaxis-management/testing-guidelines.pdf .

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.

Safety of Adrenaline Use in Anaphylaxis: A Multicentre Register

BACKGROUND

The use of intramuscular adrenaline to treat anaphylaxis is suboptimal, despite being the first-line treatment recommended by national and international anaphylaxis guidelines. Fear of potentially severe side effects may be one of the underlying factors. The aim of this study was to assess the incidence and severity of adverse side effects after the use of adrenaline in anaphylaxis, as well as potential risk factors.

METHODS

Observational study based on a multicenter online registry of cases of adrenaline administration for suspected anaphylaxis.

RESULTS

277 registered valid cases were included: 138 (51.49%) female, median age 29 years (12-47), and 6 children under 2 years with a median age of 9 months (1-21). Side effects occurred in 58 cases (21.64%), with tremors, palpitations, and anxiety being the most frequent. There was a significant association of developing side effects with older age, higher dose of adrenaline, or use of the intravenous route. Potentially severe adverse effects (high blood pressure, chest discomfort, or ECG alterations) occurred only in 8 cases (2.99%); in these cases, no differences were found according to age or adrenaline dose, but again, intravenous administration was associated with more severe adverse events.

CONCLUSION

This study shows that side effects affect less than 1 in 5 patients who receive adrenaline for an anaphylactic reaction, and are usually mild and transient. Therefore, in an emergency situation such as anaphylaxis, restricting adrenaline administration due to potential adverse effects would, in general, not be justified.

Epidemiology of anaphylaxis at a tertiary care center: A report of 730 cases

BACKGROUND

Recent data reveal that the rate of anaphylaxis is increasing and suggest that idiopathic anaphylaxis may account for most of these cases.

OBJECTIVE

To determine the pattern of anaphylaxis at a tertiary care referral center.

METHODS

A retrospective electronic medical record review spanning 12 years (2002-2013) identified patients with anaphylaxis.

RESULTS

Of the 4,777 records reviewed, 730 patients met our anaphylaxis definition. Median age was 34.0 years; 72.7% were adults, 58.6% were female, and 86.8% were white. Median time to evaluation by an allergist was 8.8 months. Foods were the most common cause (29.9%), followed by Hymenoptera venom (24.6%), idiopathic anaphylaxis (13.7%), and medications (13.3%). The most common foods were peanuts (23.9%), tree nuts (21.6%), shellfish (16.1%), and egg and milk (both 10.1%). The most common cause of anaphylaxis in adults was Hymenoptera venom. The most frequent symptoms were urticaria and/or angioedema, reported in 84.7% of cases. Atopy was present in 43.8%. In 15.4% of cases, anaphylaxis was not the chief reason for the office visit.

CONCLUSION

We found food allergy was the most common overall cause of anaphylaxis, with peanut the most frequent food trigger. Idiopathic anaphylaxis was not the most common cause but accounted for 13.7% of all cases. Approximately 1 in 6 cases of anaphylaxis may be missed if a comprehensive evaluation is not performed.

Anaphylaxis

Anaphylaxis is a systemic, life-threatening disorder triggered by mediators released by mast cells and basophils activated via allergic (IgE-mediated) or nonallergic (non-IgE-mediated) mechanisms. It is a rapidly evolving, multisystem process involving the integumentary, pulmonary, gastrointestinal, and cardiovascular systems. Anaphylaxis and angioedema are serious disorders that can lead to fatal airway obstruction and culminate in cardiorespiratory arrest, resulting in hypoxemia and/or shock. Often, these disorders can be appropriately managed in an outpatient setting; however, these conditions can be severe enough to warrant evaluation of the patient in the ED and in some cases, hospitalization, and management in an ICU. Reports suggest that underdiagnosis and undertreatment of anaphylaxis are common. Several new syndromes have been described recently including bird-egg, pork-cat, delayed allergy to mammalian meat and a diverse group of mast cell activation disorders. Conditions such as postural orthostatic tachycardia syndrome, carcinoid syndrome, Munchausen stridor, and factitious anaphylaxis can present similarly and need to be included in the differential diagnosis. Anaphylaxis is a clinical diagnosis, but plasma tryptase and urinary histamine levels are often elevated, allowing diagnostic confirmation; however, diagnostic testing should not delay treatment as results may not be immediately available. The sine qua non of treatment is avoidance of any known triggers and epinephrine, which should never be delayed if this disorder is suspected. Secondary treatments include fluids, bronchodilators, antihistamines, and glucocorticoids. Patients with cardiopulmonary arrest or airway or vascular compromise require mechanical ventilation, vasopressors, and other advanced life support in the ICU.

Probable walnut-induced anaphylactic reaction in a dog

BACKGROUND

Anaphylaxis due to nuts is frequent in humans; to the best of the authors' knowledge, it has not been reported previously in dogs.

CASE REPORT

A 5-year-old female, intact, Vizsla dog was presented with acute diarrhoea, vomiting, respiratory distress and erythematous wheals. The dog had eaten walnuts, which she had been fed in small amounts for years, hours before the onset of clinical signs. A diagnosis of generalized anaphylaxis was made. Skin testing and Western blotting revealed positive results with walnuts and hazelnuts.

CONCLUSIONS AND CLINICAL IMPORTANCE

This case report illustrates the need for a thorough food history and for recognition that a dog may experience severe allergic reactions to unusual and regularly fed food items. It also shows that allergen specific tests may help to confirm the diagnosis and help in planning the dog's future dietary regime.

The pathophysiology of anaphylaxis

Anaphylaxis is a severe systemic hypersensitivity reaction that is rapid in onset; characterized by life-threatening airway, breathing, and/or circulatory problems; and usually associated with skin and mucosal changes. Because it can be triggered in some persons by minute amounts of antigen (eg, certain foods or single insect stings), anaphylaxis can be considered the most aberrant example of an imbalance between the cost and benefit of an immune response. This review will describe current understanding of the immunopathogenesis and pathophysiology of anaphylaxis, focusing on the roles of IgE and IgG antibodies, immune effector cells, and mediators thought to contribute to examples of the disorder. Evidence from studies of anaphylaxis in human subjects will be discussed, as well as insights gained from analyses of animal models, including mice genetically deficient in the antibodies, antibody receptors, effector cells, or mediators implicated in anaphylaxis and mice that have been "humanized" for some of these elements. We also review possible host factors that might influence the occurrence or severity of anaphylaxis. Finally, we will speculate about anaphylaxis from an evolutionary perspective and argue that, in the context of severe envenomation by arthropods or reptiles, anaphylaxis might even provide a survival advantage.

Epinephrine Auto-Injector Versus Drawn Up Epinephrine for Anaphylaxis Management: A Scoping Review

OBJECTIVE

Anaphylaxis is a life-threatening event. Most clinical symptoms of anaphylaxis can be reversed by prompt intramuscular administration of epinephrine using an auto-injector or epinephrine drawn up in a syringe and delays and errors may be fatal. The aim of this scoping review is to identify and compare errors associated with use of epinephrine drawn up in a syringe versus epinephrine auto-injectors in order to assist hospitals as they choose which approach minimizes risk of adverse events for their patients.

DATA SOURCES

PubMed, Embase, CINAHL, Web of Science, and the Cochrane Library were searched using terms agreed to a priori.

STUDY SELECTION

We reviewed human and simulation studies reporting errors associated with the use of epinephrine in anaphylaxis. There were multiple screening stages with evolving feedback.

DATA EXTRACTION

Each study was independently assessed by two reviewers for eligibility. Data were extracted using an instrument modeled from the Zaza et al instrument and grouped into themes.

DATA SYNTHESIS

Three main themes were noted: 1) ergonomics, 2) dosing errors, and 3) errors due to route of administration. Significant knowledge gaps in the operation of epinephrine auto-injectors among healthcare providers, patients, and caregivers were identified. For epinephrine in a syringe, there were more frequent reports of incorrect dosing and erroneous IV administration with associated adverse cardiac events. For the epinephrine auto-injector, unintentional administration to the digit was an error reported on multiple occasions.

CONCLUSIONS

This scoping review highlights knowledge gaps and a diverse set of errors regardless of the approach to epinephrine preparation during management of anaphylaxis. There are more potentially life-threatening errors reported for epinephrine drawn up in a syringe than with the auto-injectors. The impact of these knowledge gaps and potentially fatal errors on patient outcomes, cost, and quality of care is worthy of further investigation.

National clinical practice guidelines for food allergy and anaphylaxis: an international assessment

BACKGROUND

Clinical practice guidelines are important tools to promote evidence-based clinical care, but not all countries have the capacity or infrastructure to develop these in-house. The European Academy of Allergy and Clinical Immunology has recently developed guidelines for the prevention, diagnosis and management of food allergy and the management of anaphylaxis. In order to inform dissemination, adaptation and implementation plans, we sought to identify countries that have/do not have national guidelines for food allergy and anaphylaxis.

METHODS

Two reviewers independently searched PubMed to identify countries with guidelines for food allergy and/or anaphylaxis from the inception of this database to December 2016. This was supplemented with a search of the Agency for Healthcare Research and Quality's National Guideline Clearinghouse in order to identify any additional guidelines that may not have been reported in the peer-reviewed literature. Data were descriptively and narratively synthesized.

RESULTS

Overall, 5/193 (3%) of countries had at least one guideline for food allergy or anaphylaxis. We found that one (1%) country had a national guideline for the prevention of food allergy, three (2%) countries had a guideline for the diagnosis of food allergy and three (2%) countries had a guideline for the management of food allergy. Three (2%) countries had an anaphylaxis guideline.

CONCLUSIONS

This study concludes that the overwhelming majority of countries do not have any national clinical practice guidelines for food allergy or anaphylaxis.

Insights in Anaphylaxis and Clonal Mast Cell Disorders

The prevalence of anaphylaxis among patients with clonal mast cell disorders (MCD) is clearly higher comparing to the general population. Due to a lower frequency of symptoms outside of acute episodes, clonal MCD in the absence of skin lesions might sometimes be difficult to identify which may lead to underdiagnosis, and anaphylaxis is commonly the presenting symptom in these patients. Although the release of mast cell (MC) mediators upon MC activation might present with a wide variety of symptoms, particular clinical features typically characterize MC mediator release episodes in patients with clonal MCD without skin involvement. Final diagnosis requires a bone marrow study, and it is recommended that this should be done in reference centers. In this article, we address the main triggers for anaphylaxis, risk factors, clinical presentation, diagnosis, and management of patients with MC activation syndromes (MCASs), with special emphasis on clonal MCAS [systemic mastocytosis and mono(clonal) MC activations syndromes].

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.

Anaphylaxis in the Pediatric Emergency Department: Analysis of 133 Cases After an Allergy Workup

BACKGROUND

Data on the incidence and characteristics of pediatric anaphylaxis are scarce. Reported causes of anaphylaxis are mostly those suspected by the physician in the emergency department (ED), which may not coincide with the real triggers.

OBJECTIVES

To investigate the incidence, management, and etiology of pediatric anaphylaxis in the ED of a Spanish tertiary hospital and to determine the concordance between the suspected etiology in the ED and diagnosis after the allergy workup.

METHODS

We performed an observational, descriptive study of all patients with anaphylaxis attended in the pediatric ED from 2012 to 2014. Cases were considered anaphylaxis based on National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network criteria. We recorded data on clinical characteristics, management, etiology suspected by the ED physician and patient (or relatives), and the workup performed in the allergy department.

RESULTS

We recorded 133 cases of anaphylaxis (incidence, 0.12%), with 20 cases (15%) recorded in children younger than 12 months. Anaphylaxis was correctly diagnosed in the ED in 70 cases (53%). Food allergy was the cause of anaphylaxis in 106 out of 118 studied in the allergy department (AD) (90%). The final etiology differed from the etiology initially suspected in the ED in 42 cases (39%). After the study, the frequency of patients with unidentified triggers decreased by 75%.

CONCLUSIONS

The incidence of anaphylaxis is higher in children than previously reported in adults from the same center, and food is the trigger in most cases. To prevent erroneous diagnoses, the etiology of anaphylaxis should be established after an appropriate workup.

Basophils, high-affinity IgE receptors, and CCL2 in human anaphylaxis

Background

The role of basophils in anaphylaxis is unclear.

Objective

We sought to investigate whether basophils have an important role in human anaphylaxis.

Methods

In an emergency department study we recruited 31 patients with acute anaphylaxis, predominantly to Hymenoptera venom. We measured expression of basophil activation markers (CD63 and CD203c); the absolute number of circulating basophils; whole-blood FCER1A, carboxypeptidase A3 (CPA3), and L-histidine decarboxylase (HDC) gene expression; and serum markers (CCL2, CCL5, CCL11, IL-3, and thymic stromal lymphopoietin) at 3 time points (ie, during the anaphylactic episode and in convalescent samples 7 and 30 days later). We recruited 134 patients with Hymenoptera allergy and 76 healthy control subjects for comparison. We then investigated whether the changes observed during venom-related anaphylaxis also occur during allergic reactions to food in 22 patients with peanut allergy undergoing double-blind, placebo-controlled food challenge to peanut.

Results

The number of circulating basophils was significantly lower during anaphylaxis (median, 3.5 cells/μL) than 7 and 30 days later (17.5 and 24.7 cells/μL, P < .0001) and compared with those in patients with venom allergy and healthy control subjects (21 and 23.4 cells/μL, P < .0001). FCER1A expression during anaphylaxis was also significantly lower than in convalescent samples (P ≤ .002) and control subjects with venom allergy (P < .0001). CCL2 levels (but not those of other serum markers) were significantly higher during anaphylaxis (median, 658 pg/mL) than in convalescent samples (314 and 311 pg/mL at 7 and 30 days, P < .001). Peanut-induced allergic reactions resulted in a significant decrease in circulating basophil counts compared with those in prechallenge samples (P = .016), a decrease in FCER1A expression (P = .007), and an increase in CCL2 levels (P = .003).

Conclusions

Our findings imply an important and specific role for basophils in the pathophysiology of human anaphylaxis.

Reaching multidisciplinary consensus on classification of anaphylaxis for the eleventh revision of the World Health Organization's (WHO) International Classification of Diseases (ICD-11)

Background

Although currently misclassified in the International Classification of Diseases (ICD) and still not officially listed as a rare disease, anaphylaxis is a well-known clinical emergency. Anaphylaxis is now one of the principal headings in the “Allergic and hypersensitivity conditions” section recently compiled for the forthcoming 11^th Revision of ICD (ICD-11). We here report the building process used for the pioneering “Anaphylaxis” subsection of ICD-11 in which we aimed for transparency as recommended in the ICD-11 revision guidelines.

Results

During an online intensive scientific and technical discussions with ICD-11 Topic Advisory Groups and Expert Working Groups, we drafted a total of 35 proposals for the classification of anaphylaxis. From all the 35 proposals, 77% were implemented, 20% remain to be implemented, and the others being partially implemented (1.5%) or rejected (1.5%).

Conclusion

For the first time, anaphylaxis is now properly classified and has attained greater visibility within ICD. In addition to all the benefits expected from the actions we have undertaken in updating the terminology, definitions and classification of allergic and hypersensitivity conditions for ICD-11, we strongly believe that anaphylaxis should be a public health priority and that it should therefore be formally added into the list of rare diseases in order to support awareness and quality clinical management of patients.

Managing anaphylaxis in the office setting

BACKGROUND

Although the definition of anaphylaxis for clinical use may vary by professional health care organizations and individuals, the definition consistently includes the concepts of a serious, generalized or systemic, allergic or hypersensitivity reaction that can be life-threatening or even fatal.

METHODS

In this review, we presented the important topics in the treatment of anaphylaxis in the office setting. This review will discuss triggers and risk factors, clinical diagnosis, and management of anaphylaxis in the office setting.

RESULTS

Anaphylaxis in the office setting is a medical emergency. It, therefore, is important to prepare for it, to have a posted, written anaphylaxis emergency protocol, and to rehearse the plan regularly. In this review, we presented the important steps in managing anaphylaxis in the office. Treatment of anaphylaxis should start with epinephrine administered intramuscularly at the first sign of anaphylaxis. Oxygen and intravenous fluids may be needed for moderate-to-severe anaphylaxis or anaphylaxis that is quickly developing or if the patient is unresponsive to the first injection of epinephrine. Antihistamine therapy is considered adjunctive to epinephrine, which mainly relieves itching and urticaria. Corticosteroids, with an onset of action of 4-6 hours, have no immediate effect on anaphylaxis.

CONCLUSION

To prevent near-fatal and fatal reactions from anaphylaxis, the patient, the family, and the physician must remember to follow the necessary steps when treating anaphylaxis. In anaphylaxis, there is no absolute contraindication for epinephrine.

European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI): a real-life clinical assessment

BACKGROUND

Outside clinical trials, data on systemic reactions (SRs) due to allergen immunotherapy (AIT) are scarce.

METHODS

A prospective, longitudinal, web-based survey of 'real-life' respiratory allergen immunotherapy (AIT) clinical practice was conducted in France, Germany and Spain. SRs were recorded and coded according to the Medical Dictionary for Regulatory Activities (MedDRA) and risk factors associated with SRs were identified.

RESULTS

A total of 4316 patients (corresponding to 4363 ongoing courses of AIT) were included. A total of 109 SRs were recorded, and 90 patients (2.1%) presented at least one SR. Most of the SRs occurred in subcutaneous allergen immunotherapy (SCIT) (89%, n = 97). The most frequently reported symptoms were urticaria, rhinitis, dyspnoea and cough. Respiratory symptoms appeared before skin symptoms. Most SRs occurred during the up-dosing phase (75.8%) and were mild in severity (71.6%). Intramuscular adrenaline was administered in 17 SRs, but only 65% of these were subsequently classified as anaphylaxis. Independent risk factors for SRs during SCIT were as follows: the use of natural extracts (odds ratio, OR) [95% confidence interval (CI)] = 2.74 [1.61-4.87], P = 0.001), the absence of symptomatic allergy medications (1.707 [1.008-2.892], P = 0.047), asthma diagnosis (1.74 [1.05-2.88], P = 0.03), sensitization to animal dander (1.93 [1.21-3.09], P = 0.006) or pollen (1.16 [1.03-1.30], P = 0.012) and cluster regimens (vs rush) (4.18 [1.21-14.37], P = 0.023). A previous episode of anaphylaxis increased the risk for anaphylaxis in SCIT (OR [95% CI] = 17.35 [1.91-157.28], P = 0.01).

CONCLUSION

AIT for respiratory allergy is safe, with a low number of SRs observed in real-life clinical practice. A personalized analysis of risk factors could be used to minimize SRs.

Sensitization to bovine serum albumin as a possible cause of allergic reactions to vaccines

BACKGROUND

Immediate type hypersensitivity to vaccines containing bovine/porcine excipients, such as the measles, mumps and rubella (MMR) vaccine is probably due to sensitization to bovine/porcine gelatin. Most patients with such reactions in Sri Lanka have cow's milk (CM) or beef allergy.

OBJECTIVES

We investigated whether those who had beef and CM allergy had a higher incidence of hypersensitivity reactions to vaccines and the possible trigger of such reactions.

MATERIAL AND METHODS

Twenty patients with immediate type hypersensitivity reactions to vaccines containing bovine/porcine excipients, controls with allergy to beef/pork (n=11) or CM (n=11), and 8 non atopic controls were recruited. Total serum IgE, specific IgE to beef, CM, casein, beta lactoglobulin, gelatin and bovine serum albumin (BSA) by Phadia ImmunoCap and IgE to porcine gelatin by Western blot were evaluated.

RESULTS

11/20, 5/20, 2/20, 2/20, 1/20 and 1/20 patients reported allergic reactions to measles containing, JE, rabies primary chick embryo, pentavalent, diphtheria and tetanus, and adult diphtheria and tetanus vaccines, respectively. Only one patient with allergy to vaccines had gelatin specific IgE, whereas IgE to BSA was seen in 73.3%, 90%, 66.6% and 0 of vaccine, beef or CM allergic and non-atopic controls, respectively. The mean IgE to BSA was higher in patients with allergy to vaccines, although not significant. Specific IgE to BSA was present in 54.7% of children with allergy to CM, of whom 11.8% had high levels (>17.5kUA/L). In contrast, 66.6% of these children did not have specific IgE to β-lactoglobulin, which is one of the major components of whey protein.

CONCLUSION AND CLINICAL RELEVANCE

Gelatin does not appear to play a major role in Sri Lankan children with allergy to vaccines. In contrast, due to the higher levels of BSA specific IgE, sensitization to BSA is possibly playing a role.

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.

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

BACKGROUND

In 2012, an analysis of the Brazilian mortality database demonstrated undernotification of anaphylaxis deaths due, at least in part, to difficult coding under the International Classification of Diseases (ICD)-10. This work triggered a cascade of strategic international actions supported by the Joint Allergy Academies and the ICD World Health Organization (WHO) representatives to update the classifications of allergic disorders for the ICD-11 revision. These efforts have resulted in the construction of the new 'Allergic and hypersensitivity conditions' section under the 'Disorders of the Immune system' chapter.

OBJECTIVE

To analyze the capacity of the new ICD-11 revision to capture anaphylaxis deaths.

METHODS

We re-estimated the anaphylaxis deaths that occurred in Brazil during the period 2008 to 2010, utilizing this new framework and the database of the Brazilian mortality information system that had initially been extracted in May 2011. However, in 2016, a manual review of each of the 3638 records was performed.

RESULTS

We identified 639 anaphylaxis deaths, of which 95% were classified as 'definitive anaphylaxis deaths'. In contrast to the 2012 published data, we found a higher number of cases; moreover, all 606 definitive anaphylaxis deaths would be considered as underlying causes of death utilizing the ICD-11 revision.

CONCLUSION

This study is the first example of how the new 'Allergic and hypersensitivity conditions' section of the forthcoming ICD-11 can improve the quality of official vital statistics data and the visibility of an important public health concern. This research will facilitate comprehensive, comparable population-based epidemiologic data collection on anaphylaxis.

Efficacy of a Novel Prefilled, Single-Use, Needle-Free Device (Zeneo®) in Achieving Intramuscular Agent Delivery: An Observational Study

BACKGROUND

It is recognized that, as a result of variation in tissue anatomy, current auto-injectors may have insufficient needle length to achieve successful intramuscular agent delivery in a number of patients. The Zeneo^® auto-injector is a novel prefilled, single-use, needle-free device currently in development for intradermal, subcutaneous, and intramuscular agent delivery across a variety of clinical indications. We aimed to evaluate delivery depth of the device calibrated at pressure appropriate for intramuscular (IM) administration.

METHODS

This was a prospective single-center study in healthy adult volunteers, in whom each received a single injection of saline into the anterolateral thigh. Using sequential MRI scans, we measured skin-to-muscle distance (STMD) agent delivery depth, and the success of IM agent penetration. Device dynamic pressure measurements were also recorded.

RESULTS

Results are reported for 37 subjects with evaluable MRI scans; 19 men, 18 women; mean age 38 years (range 20-58); mean BMI 27.0 kg/m² (range 21.2-30.8 kg/m²). Mean STMD values were 18.6 mm (range 13.4-23.6 mm) in women and 10.0 mm (range 5.0-21.7 mm) in men, with gender differences due primarily to greater subcutaneous thickness in women. A trend for greater STMD in subjects with BMI greater than 25 kg/m² was seen. Mean injectate penetration depths of 30.1 mm (range 20.2-45.6 mm) were observed with values similar in male and female subjects. Successful IM delivery was reported in 95% of subjects. When failure occurred, this was not due to inadequate injection depth. Device pressure (P _max) had the greatest influence on injectate muscle penetration.

CONCLUSION

Use of the Zeneo^® auto-injector achieves delivery depth that ensures intramuscular delivery in both men and women, regardless of BMI. Consistent with other reported data, STMD is greater in women.

FUNDING

Crossject.

Epinephrine inhibits vascular hyperpermeability during platelet-activating factor- or ovalbumin-induced anaphylaxis

Platelet-activating factor (PAF) has been shown to play a critical role in mediating vascular hyperpermeability during anaphylaxis.