Epinephrine absorption in children with a history of anaphylaxis

Management and Prevention of Hypersensitivity Reactions to Radiocontrast Media: A Consensus Statement from the American College of Radiology and the American Academy of Allergy, Asthma & Immunology

Intravenous iodinated contrast media (ICM) is widely used in the United States, and it is imperative to provide guidance on the management of adverse reactions to ICM as well as the preparation, planning, and potential premedication for patients with previous reactions. Currently there is a discordance between the American College of Radiology Contrast Manual, which recommends premedication to prevent repeat hypersensitivity reactions to ICM, and the Anaphylaxis 2020 Practice Parameters Update, which recommends against routine administration of glucocorticoids and/or antihistamines to prevent anaphylaxis with prior ICM hypersensitivity reactions. A task force of experts from radiology who are also members of the American College of Radiology Committee on Drugs and Contrast Media and expert allergists/immunologists including members of the Adverse Reactions to Drugs, Biologics and Latex Committee of American Academy of Allergy, Asthma & Immunology evaluated the scientific evidence to develop consensus recommendations that are endorsed by both organizations. The task force took into account the strength of evidence and balanced the potential risks of recurrent reactions with those of premedication and product avoidance when making these recommendations to improve and standardize the care of patients who experience or have a history of reaction to ICM. © Radiological Society of North America and American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc on behalf of American Academy of Allergy, Asthma & Immunology and by Radiological Society of North America. All rights are reserved, including those for text and data mining, AI training, and similar technologies. This paper was jointly developed by The Journal of Allergy and Clinical Immunology: In Practice, Radiology and jointly published by Elsevier Inc and Radiological Society of North America. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Either citation can be used when citing this article. Keywords: Contrast allergy, Contrast hypersensitivity, Iodinated contrast allergy, Iodinated contrast hypersensitivity, Anaphylaxis, Contrast skin testing, Contrast switching, Contrast reaction, Delayed contrast reaction, Immediate contrast reaction.

Management and Prevention of Hypersensitivity Reactions to Radiocontrast Media: A Consensus Statement From the American College of Radiology and the AAAAI

Intravenous iodinated contrast media (ICM) is widely used in the United States, and it is imperative to provide guidance on the management of adverse reactions to ICM as well as the preparation, planning, and potential premedication for patients with previous reactions. Currently there is a discordance between the American College of Radiology Contrast Manual, which recommends premedication to prevent repeat hypersensitivity reactions to ICM, and the Anaphylaxis 2020 Practice Parameters Update, which recommends against routine administration of glucocorticoids and/or antihistamines to prevent anaphylaxis with prior ICM hypersensitivity reactions. A task force of experts from radiology who are also members of the American College of Radiology Committee on Drugs and Contrast Media and expert allergists/immunologists including members of the Adverse Reactions to Drugs, Biologics and Latex Committee of American Academy of Allergy, Asthma & Immunology evaluated the scientific evidence to develop consensus recommendations that are endorsed by both organizations. The task force took into account the strength of evidence and balanced the potential risks of recurrent reactions with those of premedication and product avoidance when making these recommendations to improve and standardize the care of patients who experience or have a history of reaction to ICM.

Adrenaline Auto-Injectors for Preventing Fatal Anaphylaxis

Anaphylaxis affects up to 5% of people during their lifetime. Although anaphylaxis usually resolves without long-term physical consequences, it can result in anxiety and quality of life impairment. Rarely and unpredictably, community anaphylaxis can cause rapid physiological decompensation and death. Adrenaline (epinephrine) is the cornerstone of anaphylaxis treatment, and provision of adrenaline autoinjectors (AAI) has become a standard of care for people at risk of anaphylaxis in the community. In this article, we explore the effectiveness of AAIs for preventing fatal outcomes in anaphylaxis, using information drawn from animal and human in vivo studies and epidemiology. We find that data support the effectiveness of intravenous adrenaline infusions for reversing physiological features of anaphylaxis, typically at doses from 0.05 to 0.5 μg/kg/min for 1-2 h, or ~ 10 μg/kg total dose. Intramuscular injection of doses approximating 10 μg/kg in humans can result in similar peak plasma adrenaline levels to intravenous infusions, at 100-500 pg/mL. However, these levels are typically short-lived following intramuscular adrenaline, and pharmacokinetic and pharmacodynamic outcomes can be unpredictable. Epidemiological data do not support an association between increasing AAI prescriptions and reduced fatal anaphylaxis, although carriage and activation rates remain low. Taken together, these data suggest that current AAIs have little impact on rates of fatal anaphylaxis, perhaps due to a lack of sustained and sufficient plasma adrenaline concentration. Effects of AAI prescription on quality of life may be variable. There is a need to consider alternatives, which can safely deliver a sustained adrenaline infusion via an appropriate route.

Anaphylaxis

Anaphylaxis is an acute, potentially fatal systemic hypersensitivity reaction with varied mechanisms and clinical presentations. Although prompt recognition and treatment of anaphylaxis are imperative, both patients and healthcare professionals often fail to recognize and diagnose its early signs. Clinical manifestations vary widely, however, the most common signs are cutaneous symptoms, including urticaria and angioedema. Immediate intramuscular administration of epinephrine into the anterolateral thigh is first-line therapy, and is always safe even if the diagnosis is uncertain. The mainstays of long-term management include specialist assessment, allergen avoidance measures, and the provision of an epinephrine auto-injector with an individualized anaphylaxis emergency plan. This article provides an overview of the causes, clinical features, diagnosis, and acute as well as long-term management of anaphylaxis.

Pharmacokinetic and Pharmacodynamic Profile of Epinephrine Nasal Spray Versus Intramuscular Epinephrine Autoinjector in Healthy Adults

BACKGROUND

Standard of care for anaphylaxis treatment is intramuscular (IM) epinephrine. An epinephrine nasal spray (ENS) is under development as an alternative form of administration.

OBJECTIVE

To compare the pharmacokinetic and pharmacodynamic (PD) profile of 13.2 mg ENS with 0.3 mg IM epinephrine autoinjector.

METHODS

Data from 4 open-label phase 1 crossover studies conducted in healthy adults were pooled to determine the pharmacokinetic and PD profile of a single 13.2 mg ENS dose delivered by 2 consecutive sprays of 6.6 mg each in opposite (n = 224 doses) or the same nostril (n = 75 doses) compared with the 0.3 mg IM autoinjector (n = 215 doses). Each participant served as their own control. Blood samples and vital signs were collected predose and at multiple intervals from 0 to 360 minutes postdose.

RESULTS

ENS rapidly increased the plasma epinephrine concentration, with levels that were overall greater than IM autoinjector. Median (range) time to maximum plasma epinephrine concentration with ENS opposite nostrils, ENS same nostril, and IM autoinjector was 25.1 (1.3-362.1), 20.1 (3.0-120.2), and 20.0 (1.0-121.3) minutes, respectively. The area under the plasma concentration-time curve for 0 to 360 minutes was significantly higher with ENS than with the IM autoinjector (geometric mean ratio [90% CI], 155% [140%-172%] with ENS opposite nostrils, 159% [138%-182%] with ENS same nostril). The PD effects on heart rate and blood pressure were similar in pattern and magnitude among all 3 treatment groups.

CONCLUSIONS

ENS rapidly achieved plasma epinephrine levels greater and more sustained than the IM autoinjector and with a similar PD effect.

Frequencies and predictors of subcutaneous and intraosseous injection with 4 epinephrine autoinjector devices

BACKGROUND

To prevent anaphylaxis-associated illness, intramuscular epinephrine injection is recommended. Subcutaneous injection may reduce efficacy, and intraosseous injection promotes morbidity. A few studies suggested that commercially available thigh epinephrine autoinjectors (EAIs) may induce subcutaneous/intraosseous injection in some adults.

OBJECTIVE

To estimate the subcutaneous/intraosseous-injection rates of 4 EAIs by comparing their needle lengths with the ultrasound-measured skin-to-muscle depth and skin-to-bone depth of the midthigh of adults with allergic diseases in a cross-sectional study and to determine patient factors that predict subcutaneous EAI injection.

METHODS

Thigh ultrasound was conducted in a convenience-recruited cohort with minimal and maximal compression to estimate the effect of EAI-induced compression. Subcutaneous/intraosseous-injection rates were estimated for Anapen (BioProject), EpiPen (Mylan), Jext (ALK), and Emerade (Medeca). Multivariate analyses for subcutaneous-injection risk were conducted with age, male/female sex, abdominal and thigh circumferences, and upper-arm skinfold thickness.

RESULTS

A total of 68 patients were recruited. Compression thinned the subcutaneous tissue and muscle by 1 and 9 mm, respectively, on average. Projected subcutaneous-injection rates with/without compression were high for Anapen (65%-66%), moderate for EpiPen and Jext (29%-38%), and lowest for Emerade (13%-21%). Compression introduced a small intraosseous-injection risk with Emerade (4%). Female sex predicted subcutaneous injection (odds ratio, 1.3-2.0; all P < .001). Depending on the EAI, 29% to 97% of women and 0% to 41% of men would be injected subcutaneously. Older men were at risk of intraosseous Emerade injection. Obesity-related variables predicted subcutaneous injection poorly.

CONCLUSION

Anapen was associated with high subcutaneous-injection rates. EpiPen and Jext were projected to provide intramuscular injection in all men without risk of intraosseous injection. Emerade yielded the lowest subcutaneous-injection rates in women. Compression largely affected the muscle.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02886468.

Clinical Practice Guideline: Immunotherapy for Inhalant Allergy

OBJECTIVE

Allergen immunotherapy (AIT) is the therapeutic exposure to an allergen or allergens selected by clinical assessment and allergy testing to decrease allergic symptoms and induce immunologic tolerance. Inhalant AIT is administered to millions of patients for allergic rhinitis (AR) and allergic asthma (AA) and is most commonly delivered as subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). Despite its widespread use, there is variability in the initiation and delivery of safe and effective immunotherapy, and there are opportunities for evidence-based recommendations for improved patient care.

PURPOSE

The purpose of this clinical practice guideline (CPG) is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the management of inhaled allergies with immunotherapy. Specific goals of the guideline are to optimize patient care, promote safe and effective therapy, reduce unjustified variations in care, and reduce the risk of harm. The target patients for the guideline are any individuals aged 5 years and older with AR, with or without AA, who are either candidates for immunotherapy or treated with immunotherapy for their inhalant allergies. The target audience is all clinicians involved in the administration of immunotherapy. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of inhaled allergies with immunotherapy. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made a strong recommendation that (Key Action Statement [KAS] 10) the clinician performing allergy skin testing or administering AIT must be able to diagnose and manage anaphylaxis. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should offer or refer to a clinician who can offer immunotherapy for patients with AR with or without AA if their patients' symptoms are inadequately controlled with medical therapy, allergen avoidance, or both, or have a preference for immunomodulation. (KAS 2A) Clinicians should not initiate AIT for patients who are pregnant, have uncontrolled asthma, or are unable to tolerate injectable epinephrine. (KAS 3) Clinicians should evaluate the patient or refer the patient to a clinician who can evaluate for signs and symptoms of asthma before initiating AIT and for signs and symptoms of uncontrolled asthma before administering subsequent AIT. (KAS 4) Clinicians should educate patients who are immunotherapy candidates regarding the differences between SCIT and SLIT (aqueous and tablet) including risks, benefits, convenience, and costs. (KAS 5) Clinicians should educate patients about the potential benefits of AIT in (1) preventing new allergen sensitizations, (2) reducing the risk of developing AA, and (3) altering the natural history of the disease with continued benefit after discontinuation of therapy. (KAS 6) Clinicians who administer SLIT to patients with seasonal AR should offer pre- and co-seasonal immunotherapy. (KAS 7) Clinicians prescribing AIT should limit treatment to only those clinically relevant allergens that correlate with the patient's history and are confirmed by testing. (KAS 9) Clinicians administering AIT should continue escalation or maintenance dosing when patients have local reactions (LRs) to AIT. (KAS 11) Clinicians should avoid repeat allergy testing as an assessment of the efficacy of ongoing AIT unless there is a change in environmental exposures or a loss of control of symptoms. (KAS 12) For patients who are experiencing symptomatic control from AIT, clinicians should treat for a minimum duration of 3 years, with ongoing treatment duration based on patient response to treatment. The GDG offered the following KASs as options: (KAS 2B) Clinicians may choose not to initiate AIT for patients who use concomitant beta-blockers, have a history of anaphylaxis, have systemic immunosuppression, or have eosinophilic esophagitis (SLIT only). (KAS 8) Clinicians may treat polysensitized patients with a limited number of allergens.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Preventing food allergy fatalities

Fatal anaphylaxis to food is thankfully rare, but every death is a potentially avoidable tragedy. Usually, there will be a coronial inquest to establish the 'how and why' for each death. Reviewing these food allergy-related deaths identifies a number of common themes and risk factors. While some are non-modifiable (such as age, gender and ethnicity), others are and include delayed epinephrine administration and communication difficulties in allergen avoidance. This review highlights the key messages in food allergy-related fatality prevention for healthcare professionals and patients alike, and where available, we explain the evidence behind such recommendations. We describe the data behind the good practice points to facilitate their adoption in routine practice without generating additional anxiety for what is a comparatively rare event. We also propose an information leaflet for patients and carers, developed with patients and endorsed by two major allergy charities, to facilitate dissemination of the recommendations in this review.

Anaphylaxis: Emergency Department Treatment

Anaphylaxis is a potentially life-threatening, multisystem allergic reaction that can cause airway, breathing, or circulatory compromise. Intramuscular epinephrine is the immediate treatment of all patients. Intravenous epinephrine should be used in patients in shock, either as a bolus or infusion, along with fluid resuscitation. Airway obstruction must be recognized, and early intubation may be necessary. For shock that is refractory to epinephrine, additional vasopressors may be needed. Disposition depends on patient presentation and response to treatment. Mandatory observation periods are not necessary, because biphasic reactions are difficult to predict and may occur outside of typical observation periods.

Optimal dose of adrenaline auto-injector for children and young people at risk of anaphylaxis: A phase IV randomized controlled crossover study

BACKGROUND

Guidelines recommend intramuscular injection of 500 μg adrenaline (epinephrine) for anaphylaxis in teenagers and adults; however, most autoinjectors deliver a maximum 300 μg dose. We evaluated plasma adrenaline levels and cardiovascular parameters (including cardiac output) following self-injection with 300 μg or 500 μg adrenaline in teenagers at risk of anaphylaxis.

METHODS

Subjects were recruited to a randomized, single-blind two period crossover trial. Participants received all 3 injections (Emerade® 500 μg, Emerade® 300 μg, Epipen® 0.3 mg) on 2 separate visits (allocated in a randomized block design), at least 28 days apart. Intramuscular injection was confirmed by ultrasound, and heart rate/stroke volume assessed using continuous monitoring. The trial was registered at Clinicaltrials.gov (NCT03366298).

RESULTS

Twelve participants (58% male, median 15.4 years) participated; all completed the study. 500 μg injection resulted in a higher and more prolonged peak concentration (p = 0.01) and greater Area-Under-Curve for plasma adrenaline (p < 0.05) compared to 300 μg, with no difference in adverse events. Adrenaline caused a significant increase in heart rate irrespective of dose and device. Unexpectedly, 300 μg adrenaline resulted in a significant increase in stroke volume when delivered with Emerade®, but a negative inotropic effect with Epipen® (p < 0.05).

CONCLUSIONS

These data support a 500 μg dose of adrenaline to treat anaphylaxis in individuals >40 kg in the community. The contrasting effects on stroke volume between Epipen® and Emerade®, despite similar peak plasma adrenaline levels, are unexpected. There is an urgent need to better understand differences in pharmacodynamics following adrenaline administration by autoinjector. In the meantime, we recommend adrenaline injection by needle/syringe in the healthcare setting in individuals with anaphylaxis refractory to initial treatment.

Epinephrine autoinjectors: individualizing device and dosage to optimize anaphylaxis management in the community setting

Background: Anaphylaxis is the most severe manifestation of a systemic allergic reaction, and, in the community setting, the immediate administration of an epinephrine autoinjector (EAI) can be life-saving. Physicians are tasked with selecting the most appropriate EAI for each individual and counseling patients and/or their caregivers to maximize the likelihood of successful deployment of the EAI. Objective: To offer an evidence-based expert clinical perspective on how physicians might best tailor EAI selection to their patients with anaphylaxis. Methods: A group of eight adult and pediatric allergists with expertise in anaphylaxis management reviewed and assessed the published data and guidelines on anaphylaxis management and EAI device selection. Results: Personalized EAI selection is influenced by intrinsic individual factors, extrinsic factors such as the properties of the individual EAI (e.g., dose, needle length, overall design) as well as cost and coverage. The number and the variety of EAIs available have expanded in most jurisdictions in recent years, which provide a greater diversity of options to meet the characteristics and needs of patients with anaphylaxis. Conclusion: There currently are no EAIs with customizable dose and needle length. Although precise personalization of each patient's EAI remains an optimistic future aspiration, careful consideration of all variables when prescribing EAIs can support optimal management of anaphylaxis.

Critical Upper Airway Edema After a Bee Sting to the Uvula

Hymenoptera stings of the upper airway are rare events, but can result in rapid, life-threatening airway emergencies. The allergenic and toxic mediators that are released from the stings of bees, wasps, and hornets can cause local tissue inflammation and edema with subsequent upper airway obstruction. We report the case of a 15-y-old girl who suffered a bee sting to the uvula while zip-lining in Costa Rica. Shortly thereafter, she developed a choking sensation with associated dysphonia, odynophagia, drooling, and respiratory distress. She was brought to a rural emergency medical clinic where she was noted to have an erythematous, edematous, boggy uvula, with a black stinger lodged within it, as well as edema of the anterior pillars of the tonsils and soft palate. The stinger was removed with tweezers and she was treated with an intravenous corticosteroid and antihistamine. She had persistence of airway edema and symptoms until the administration of epinephrine, which resulted in clinical improvement shortly thereafter. In our review of this case and the existing literature, we emphasize the importance of early recognition and management of hymenoptera stings of the upper airway, which should always include immediate manual removal of the stinger, and in cases with significant upper airway edema, the administration of epinephrine should be considered.

A Clinical Practice Guideline for the Emergency Management of Anaphylaxis (2020)

Background: For anaphylaxis, a life-threatening allergic reaction, the incidence rate was presented to have increased from the beginning of the 21st century. Underdiagnosis and undertreatment of anaphylaxis are public health concerns. Objective: This guideline aimed to provide high-quality and evidence-based recommendations for the emergency management of anaphylaxis. Method: The panel of health professionals from fifteen medical areas selected twenty-five clinical questions and formulated the recommendations with the supervision of four methodologists. We collected evidence by conducting systematic literature retrieval and using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: This guideline made twenty-five recommendations that covered the diagnosis, preparation, emergency treatment, and post-emergency management of anaphylaxis. We recommended the use of a set of adapted diagnostic criteria from the American National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network (NIAID/FAAN), and developed a severity grading system that classified anaphylaxis into four grades. We recommended epinephrine as the first-line treatment, with specific doses and routes of administration for different severity of anaphylaxis or different conditions. Proper dosage is critical in the administration of epinephrine, and the monitor is important in the IV administration. Though there was only very low or low-quality evidence supported the use of glucocorticoids and H1 antagonists, we still weakly recommended them as second-line medications. We could not make a well-directed recommendation regarding premedication for preventing anaphylaxis since it is difficult to weigh the concerns and potential effects. Conclusion: For the emergency management of anaphylaxis we conclude that: • NIAID/FAAN diagnostic criteria and the four-tier grading system should be used for the diagnosis • Prompt and proper administration of epinephrine is critical.

EAACI guidelines: Anaphylaxis (2021 update)

Anaphylaxis is a clinical emergency which all healthcare professionals need to be able to recognize and manage. The European Academy of Allergy and Clinical Immunology Anaphylaxis multidisciplinary Task Force has updated the 2014 guideline. The guideline was developed using the AGREE II framework and the GRADE approach. The evidence was systematically reviewed and recommendations were created by weighing up benefits and harms. The guideline was peer-reviewed by external experts and reviewed in a public consultation. The use of clinical criteria to identify anaphylaxis is suggested with blood sampling for the later measurement of tryptase. The prompt use of intramuscular adrenaline as first-line management is recommended with the availability of adrenaline autoinjectors to patients in the community. Pharmacokinetic data should be provided for adrenaline autoinjector devices. Structured, comprehensive training for people at risk of anaphylaxis is recommended. Simulation training and visual prompts for healthcare professionals are suggested to improve the management of anaphylaxis. It is suggested that school policies reflect anaphylaxis guidelines. The evidence for the management of anaphylaxis remains mostly at a very low level. There is an urgent need to prioritize clinical trials with the potential to improve the management of patients at risk of anaphylaxis.

Pharmacokinetics of adrenaline autoinjectors

Anaphylaxis is a medical emergency with adrenaline acknowledged as the first-line therapy. It is therefore important that patients have access to self-injectable adrenaline in the community. Manufacturers have been requested by European Medicine Regulators to generate pharmacokinetic data for these autoinjector devices. For the first time, these data provide an insight into how individual devices work in different populations, and how they compare. We undertook a thorough literature search and also accessed grey literature, using searches of medicine regulators' websites and freedom of information requests. The data demonstrate that it takes at least 5-10 min to achieve early peak plasma concentration for most devices. The specific autoinjector device seems to be the most important determinant of pharmacokinetics, with different devices giving rise to different plasma adrenaline profiles. Needle length does not seem to be the most important factor; rather, the force and speed of injection (which varies from one device to another) is likely to be of greater importance. In general, peak plasma adrenaline concentration is lower and time-to-peak concentration longer with increased skin-to-muscle depth. However, it is difficult to draw conclusions with the current available data, due to a lack of head-to-head comparisons, small numbers of study participants and the failure to acknowledge the biphasic nature of intramuscular adrenaline absorption for analysis purposes.

Anaphylaxis: Emergency Department Treatment

Anaphylaxis is a potentially life-threatening, multisystem allergic reaction that can cause airway, breathing, or circulatory compromise. Intramuscular epinephrine is the immediate treatment of all patients. Intravenous epinephrine should be used in patients in shock, either as a bolus or infusion, along with fluid resuscitation. Airway obstruction must be recognized, and early intubation may be necessary. For shock that is refractory to epinephrine, additional vasopressors may be needed. Disposition depends on patient presentation and response to treatment. Mandatory observation periods are not necessary, because biphasic reactions are difficult to predict and may occur outside of typical observation periods.

Diagnosing, managing and preventing anaphylaxis: Systematic review

BACKGROUND

This systematic review used the GRADE approach to compile evidence to inform the European Academy of Allergy and Clinical Immunology's (EAACI) anaphylaxis guideline.

METHODS

We searched five bibliographic databases from 1946 to 20 April 2020 for studies about the diagnosis, management and prevention of anaphylaxis. We included 50 studies with 18 449 participants: 29 randomized controlled trials, seven controlled clinical trials, seven consecutive case series and seven case-control studies. Findings were summarized narratively because studies were too heterogeneous to conduct meta-analysis.

RESULTS

It is unclear whether the NIAID/FAAN criteria or Brighton case definition are valid for immediately diagnosing anaphylaxis due to the very low certainty of evidence. There was also insufficient evidence about the impact of most anaphylaxis management and prevention strategies. Adrenaline is regularly used for first-line emergency management of anaphylaxis but little robust research has assessed its effectiveness. Newer models of adrenaline autoinjectors may slightly increase the proportion of people correctly using the devices and reduce time to administration. Face-to-face training for laypeople may slightly improve anaphylaxis knowledge and competence in using autoinjectors. We searched for but found little or no comparative effectiveness evidence about strategies such as fluid replacement, oxygen, glucocorticosteroids, methylxanthines, bronchodilators, management plans, food labels, drug labels and similar.

CONCLUSIONS

Anaphylaxis is a potentially life-threatening condition but, due to practical and ethical challenges, there is a paucity of robust evidence about how to diagnose and manage it.

Ideal body position for epinephrine autoinjector administration

Background: Epinephrine is the first-line therapy for patients with anaphylaxis, and intramuscular (IM) delivery is shown to be superior to subcutaneous (SC) delivery. There currently is no consensus on the ideal body position for epinephrine autoinjector (EAI) administration. Objective: We designed this study to investigate whether SC tissue depth (SCTD) is affected by body position (e.g., standing, sitting, supine), which can potentially impact delivery of EAI into the IM space. Methods: Volunteer adults (ages ≥ 18 years) from a military medical treatment facility in the United States were recruited to participate in this study. SCTD of the vastus lateralis was measured via ultrasound at standing, sitting, and supine body positions. Subjects' age, sex, and body mass index (BMI) were collected. Statistical analysis was performed to compare average SCTD between body positions, sex, and BMI. Results: An analysis of variance of 51 participants (33 men and 18 women) did not reveal statistically significant difference in SCTD among standing, sitting, and supine body positions. It did show a significantly greater SCTD in women than in men (2.72 ± 1.36 cm versus 1.10 ± 0.38 cm; p < 0.001). There was no significant association observed between BMI and SCTD in this study. Conclusion: Body position did not seem to significantly change the distance between skin and thigh muscle in adults. This would suggest that there might not be an ideal body position for EAI administration. Therefore, in case of anaphylaxis, prompt administration of epinephrine is recommended at any position.

The pharmacokinetics of epinephrine/adrenaline autoinjectors

Background

For a century, epinephrine has been the drug of choice for acute treatment of systemic allergic reactions/anaphylaxis. For 40 years, autoinjectors have been used for the treatment of anaphylaxis. Over the last 20 years, intramuscular epinephrine injected into the thigh has been recommended for optimal effect.

Objective

To review the literature on pharmacokinetics of epinephrine autoinjectors.

Results

Six studies assessing epinephrine autoinjector pharmacokinetics were identified. The studies, all on healthy volunteers, were completed by Simons, Edwards, Duvauchelle, Worm and Turner over the span of 2 decades. Simons et al. published two small studies that suggested that intramuscular injection was superior to subcutaneous injection. These findings were partially supported by Duvauchelle. Duvauchelle showed a proportional increase in C_max and AUC_0-20 when increasing the dose from 0.3 to 0.5 mg epinephrine intramuscularly. Turner confirmed these findings. Simons, Edwards and Duvauchelle documented the impact of epinephrine on heart rate and blood pressure. Turner confirmed a dose-dependent increase in heart rate, cardiac output and stroke volume. Based on limited data, confirmed intramuscular injections appeared to lead to faster C_max. Two discernable C_max’s were identified in most of the studies. We identified similarities and discrepancies in a number of variables in the aforementioned studies.

Conclusions

Intramuscular injection with higher doses of epinephrine appears to lead to a higher C_max. There is a dose dependent increase in plasma concentration and AUC_0-20. Most investigators found two C_max’s with T_max 5–10 min and 30–50 min, respectively. There is a need for conclusive trials to evaluate the differences between intramuscular and subcutaneous injections with the epinephrine delivery site confirmed with ultrasound.

Autoinjector device for rapid administration of drugs and antidotes in emergency situations and in mass casualty management

There are several situations such as medical emergencies and incidents involving mass casualties where drugs and antidotes have to be administered immediately along with other first aid at the site of the event. Self-administration by the affected person or by a companion is required as a life-saving measure. Autoinjector devices (AIDs) are useful for the rapid administration of drugs and antidotes and they can also be used by those who have not been medically trained. This makes them very convenient for emergency and mass casualty management. An AID has a drug cartridge with an embedded needle for subcutaneous or intramuscular injection, which is usually painless. The drugs are delivered slowly by the AID across a large area in the muscle, which increases the absorption and the drug effects are equal to that of intravenous administration. A variety of AIDs are available, such as atropine and pralidoxime for nerve agent poisoning, epinephrine for anaphylactic shock and allergy, diazepam for seizures, sumatriptan for migraine, amikacin for antibacterial treatment, buprenorphine for pain relief and monoclonal antibodies for a variety of diseases. This review describes the published peer-reviewed literature identified by online searches of journal databases.

Emerging Therapies in Anaphylaxis: Alternatives to Intramuscular Administration of Epinephrine

PURPOSE OF REVIEW

Anaphylaxis is a severe, life-threatening, systemic allergic reaction that should be recognized and treated promptly. Intramuscular (IM) epinephrine is the first-line treatment for anaphylaxis and there are no absolute contraindications to its use. Despite its established track record of efficacy and safety, physicians and patients face barriers in the recognition and treatment of anaphylaxis, including the maintenance and appropriate use of epinephrine auto-injectors. This has led to investigation into potential alternatives to IM epinephrine administration in anaphylaxis.

RECENT FINDINGS

This review investigates the current standard of care in the treatment of anaphylaxis, barriers to IM epinephrine use, and alternative therapies under investigation for administration in anaphylaxis. Alternative routes under investigation include intranasal, sublingual, inhaled, and needle-free intramuscular administration of epinephrine. There are currently numerous investigational alternatives to IM epinephrine therapy which could hold promise as future effective treatments in the emergent management of anaphylaxis.

Got a Pen for Allergen Immunotherapy? Lessons from Near-Fatal Anaphylaxis with Pulmonary Edema

On our pediatric intensive care unit, we successfully treated a 10-year-old boy with severe pulmonary edema due to anaphylaxis after his last injection of a 3-year course of allergen immunotherapy (AIT). In view of the severity of the adverse event, we initiated a case analysis with all involved medical professionals. The evaluation revealed delayed administration of epinephrine due to dosing uncertainty and underestimation of severity. Consequently, all involved institutions established epinephrine auto-injectors (EAIs) in their emergency equipment. We suggest providing EAIs in every practice conducting AIT, as well as in pediatric emergency rooms and ambulances. We would like to remind readers of the risk of anaphylaxis, even on the last day of AIT.

Hemodynamic Changes with 1:1000 Epinephrine on Wrung-Out Pledgets Before and During Sinus Surgery

BACKGROUND

Intranasal topical 1:1000 epinephrine has been used safely and effectively for hemostasis during endoscopic sinus surgery (ESS). Prior studies assessing hemodynamic changes after intranasal topical epinephrine application have only used soaking wet cottonoid pledgets, and have only assessed for hemodynamic changes before any surgery being performed.

OBJECTIVE

The purposes of this study were to determine whether intranasal application of topical 1:1000 epinephrine with wrung-out cottonoid pledgets caused significant hemodynamic changes both before and during ESS, and whether it allowed for adequate hemostasis.

METHODS

A prospective evaluation of 30 patients with eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) undergoing complete bilateral ESS was conducted. Heart rate, blood pressure (systolic, diastolic, and mean arterial pressure), and electrocardiography changes were recorded at 0, 1, 2, and 5-minute intervals after placing wrung-out epinephrine-saturated pledgets, both before and at the end of ESS. No submucosal epinephrine injections were performed. Estimated blood loss (EBL) and major intraoperative complications were recorded for all cases.

RESULTS

There were no significant hemodynamic changes or electrocardiographic abnormalities after placement of wrung-out epinephrine-soaked pledgets both before and after ESS. After bilateral ESS, there were actually mean decreases in heart rate and blood pressure parameters. Mean EBL was 75.8 ± 32.2 mL, and no major intraoperative complications occurred.

CONCLUSION

Intranasal application of topical 1:1000 epinephrine via wrung-out cottonoid pledgets was effective for intraoperative hemostasis, and did not cause clinically significant alterations in hemodynamic parameters or cardiovascular events, either before or during ESS in patients with CRSwNP.Level of Evidence: 4.

Pharmacokinetic and pharmacodynamic evidence of adrenaline administered via auto-injector for anaphylactic reactions: A review of literature

Anaphylaxis is a severe allergic reaction that can lead to death if not treated quickly. Adrenaline (epinephrine) is the first-line treatment for anaphylaxis and its prompt administration is vital to reduce mortality. Following a number of high-profile cases, serious concerns have been raised, both about the optimal dose of intramuscular adrenaline via an auto-injector and the correct needle length to ensure maximal penetration every time. To date, the public data are sparse on the pharmacokinetics-pharmacodynamics of adrenaline administered via an auto-injector. The limited available literature showed a huge variation in the plasma concentrations of adrenaline administered through an auto-injector, as well as variations in the auto-injector needle length. Hence, delivering an effective dose during an anaphylaxis remains a challenge for both patients and healthcare professionals. Collaborative work between pharmacokinetics-pharmacodynamics experts, clinical triallists and licence holders is imperative to address this gap in evidence so that we can improve outcomes of anaphylaxis. In addition, we advise inclusion of expertise of human factors in usability studies given the necessity of carer or self-administration in the uniquely stressful nature of anaphylaxis.

Japanese guidelines for food allergy 2020

Five years have passed since the Japanese Pediatric Guideline for Food Allergy (JPGFA) was first revised in 2011 from its original version. As many scientific papers related to food allergy have been published during the last 5 years, the second major revision of the JPGFA was carried out in 2016. In this guideline, food allergies are generally classified into four clinical types: (1) neonatal and infantile gastrointestinal allergy, (2) infantile atopic dermatitis associated with food allergy, (3) immediate-type of food allergy (urticaria, anaphylaxis, etc.), and (4) special forms of immediate-type of food allergy such as food-dependent exercise-induced anaphylaxis and oral allergy syndrome (OAS). Much of this guideline covers the immediate-type of food allergy that is seen during childhood to adolescence. Infantile atopic dermatitis associated with food allergy type is especially important as the onset of most food allergies occurs during infancy. We have discussed the neonatal and infantile gastrointestinal allergy and special forms of immediate type food allergy types separately. Diagnostic procedures are highlighted, such as probability curves and component-resolved diagnosis, including the recent advancement utilizing antigen-specific IgE. The oral food challenge using a stepwise approach is recommended to avoid complete elimination of causative foods. Although oral immunotherapy (OIT) has not been approved as a routine treatment by nationwide insurance, we included a chapter for OIT, focusing on efficacy and problems. Prevention of food allergy is currently the focus of interest, and many changes were made based on recent evidence. Finally, the contraindication between adrenaline and antipsychotic drugs in Japan was discussed among related medical societies, and we reached an agreement that the use of adrenaline can be allowed based on the physician's discretion. In conclusion, this guideline encourages physicians to follow the principle to let patients consume causative foods in any way and as early as possible.

Subcutaneous Immunotherapy Safety: Incidence per Surveys and Risk Factors

Subcutaneous immunotherapy (SCIT) is effective for allergic rhinitis and conjunctivitis, asthma, and insect venom hypersensitivity. The risk of severe allergic reactions induced by SCIT remains low, and mild systemic reactions have recently shown a tendency to decline. However, near-fatal and fatal anaphylactic reactions may occur. Clinicians administering allergen-specific immunotherapy should receive specialized training and be aware of risk factors and preventive measures to avoid severe allergic reactions induced by SCIT.

Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.

The Hemodynamic Effect of Epinephrine-Containing Local Infiltration Analgesia After Tourniquet Deflation During Total Knee Arthroplasty: A Retrospective Observational Study

BACKGROUND

Local infiltration analgesia (LIA) is widely used in patients undergoing total knee arthroplasty and often contains epinephrine for a prolonged analgesic effect and to reduce systemic absorption of the local anesthetic. This retrospective observational study investigated the hemodynamic effect of locally infiltrated epinephrine after deflation of the tourniquet during total knee arthroplasty.

METHODS

We reviewed the electronic medical records of patients who underwent total knee arthroplasty between January 2017 and February 2018 at a tertiary care university hospital. Total knee arthroplasty was performed using a conventional technique with a pneumatic tourniquet. LIA consisted of ropivacaine, morphine sulfate, ketorolac, and methylprednisolone. The patients were grouped according to whether or not epinephrine was included in the LIA. The incidence of a hypertensive response (systolic blood pressure >160 mmHg or mean blood pressure >110 mmHg) after deflation of the tourniquet was compared between the 2 groups.

RESULTS

A total of 452 patients had received LIA with (n = 188) or without (n = 264) epinephrine. A hypertensive response after deflation of the tourniquet was more common in patients who received LIA containing epinephrine (42/188 [22.3%]) than in those who received LIA without epinephrine (14/264 [5.3%], P < .001). However, the incidence of hypotension after deflation of the tourniquet was not significantly different between the 2 groups (P = .976).

CONCLUSION

Because epinephrine-containing LIA can result in a hypertensive response after deflation of the tourniquet during total knee arthroplasty, it should be cautiously administered, especially in patients with cardiovascular comorbidities.

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

Anaphylactic reaction after local lidocaine infiltration for retraction of retained teeth

Although allergic reactions are not rare complications in drug use, anaphylaxis or anaphylactoid reactions to some widely used drugs can embarrass clinicians because anaphylaxis is not easily diagnosed at the time of the event and treatment is unfamiliar to many. Lidocaine is a very popular drug in dental procedures and anaphylactoid reaction to it has been rarely reported. Clinicians who use lidocaine daily should, however, be aware of the possibility of anaphylaxis after its use. Once it occurs, anaphylaxis can be fatal, but if it is quickly diagnosed or suspected, treatment is simpler than most clinicians believe. An 86-year-old woman experienced an anaphylactic reaction 30 min after local infiltration of lidocaine for retraction of retained teeth. The dentist called an anesthesiologist for assistance. Fortunately, an anaphylactic reaction was quickly suspected and after subsequent rapid treatment with the administration of fluid and drug therapy, the patient recovered completely.

Point-of-care ultrasonography in the allergy and immunology clinic

OBJECTIVE

To summarize evidence supporting the use of point-of-care ultrasonography as a clinical tool for allergists and immunologists.

DATA SOURCES

Cochrane Library, Medline, EMBASE, and Scopus databases were searched for articles published before December 18, 2018.

STUDY SELECTIONS

We included any retrospective or prospective study that evaluated ultrasonography in allergy and immunology and epinephrine autoinjector (EAI) needle length.

RESULTS

The standard EAI needle length may be inadequate for intramuscular delivery of epinephrine, particularly for women, at risk of anaphylaxis. In patients who weigh less than 15 kg, the lengths of commercially available EAIs may be too long, risking inadvertent intraosseous injection and resultant complications. Ultrasonography can be routinely used in the allergy clinic to guide needle length and angle for subcutaneous allergen immunotherapy injections to minimize systemic adverse effects.

CONCLUSION

Point-of-care ultrasonography can be a useful tool to enhance patient care and safety in an allergy clinic. Ideally, all patients prescribed EAIs should have ultrasonographic measurement of the skin to muscle distance and skin to bone distance to assist in identifying patients at risk of subcutaneous or intraosseous injection in anaphylaxis and those at risk of intramuscular injection during subcutaneous allergen immunotherapy injections.

Guiding Principles for the Recognition, Diagnosis, and Management of Infants with Anaphylaxis: An Expert Panel Consensus

Infant anaphylaxis is an emerging risk, with food allergy the most common cause. Although the presentation of anaphylaxis involves the same systems as in older children and adults, there are real-world challenges to identifying symptoms of an allergic emergency in nonverbal children, as well as implementing optimal treatment. Recognition of anaphylaxis in infants can be challenging because allergic symptoms and certain normal infant behaviors may overlap. Intramuscular epinephrine is the treatment of choice for infants, as it is for older children and adults, and an epinephrine autoinjector approved by the Food and Drug Administration is now available for infants weighing between 7.5 and 15 kg. A panel of experts sought to develop guiding principles for the recognition, diagnosis, and management of anaphylaxis in infants, and provide a framework for the development of new guidelines and future research. Accordingly, anaphylaxis emergency action planning for infants was addressed by the panel. In considering formation of future infant anaphylaxis guidelines, health care providers should be aware of the needs to improve the recognition, diagnosis, and management of infants with anaphylaxis. Future research should identify and validate clinical criteria for the diagnosis of anaphylaxis in infants, as well as risk factors for the most severe reactions.

Anaphylaxis

Anaphylaxis is an acute, potentially fatal systemic allergic reaction with varied mechanisms and clinical presentations. Although prompt recognition and treatment of anaphylaxis are imperative, both patients and healthcare professionals often fail to recognize and diagnose early signs and symptoms of the condition. Clinical manifestations vary widely; however, the most common signs are cutaneous symptoms, including urticaria, angioedema, erythema and pruritus. Immediate intramuscular administration of epinephrine into the anterolateral thigh is first-line therapy, even if the diagnosis is uncertain. The mainstays of long-term management include specialist assessment, avoidance measures, and the provision of an epinephrine auto-injector and an individualized anaphylaxis action plan. This article provides an overview of the causes, clinical features, diagnosis and acute and long-term management of this serious allergic reaction.

Management of anaphylaxis and allergies in patients with long QT syndrome: A review of the current evidence

OBJECTIVE

To develop a treatment algorithm for patients with long QT syndrome (LQTS) in case they need antiallergic medications for allergic reactions, including asthma and anaphylaxis.

DATA SOURCES

A literature review was performed to assess safety and to develop antiallergic treatment strategies for patients with LQTS.

STUDY SELECTIONS

LQTS is a heterogeneous group of myocardial repolarization disorders characterized by prolongation of the QT interval that potentially results in life-threatening torsades de pointes tachycardia. Data on pharmacologic treatment in case of anaphylaxis in LQTS are sparse. For this narrative review, all currently available articles on the use of antiallergic drugs for allergic reactions, anaphylaxis, and asthma in patients with LQTS were used.

RESULTS

Local allergic symptoms can be safely treated primarily with fexofenadine, levocetirizine, desloratadine, or cetirizine and, if needed, a short course of corticosteroids. In case of systemic symptoms, epinephrine should be administered. It may be less effective in patients with LQTS treated with β-blockers, necessitating the use of glucagon as add-on treatment. In case of lower airway obstruction, ipratropium bromide should be used, but if not effective, inhaled β₂-adrenergic agents may be used. Continuous cardiac monitoring is indicated with the use of epinephrine and inhaled β₂-adrenergic agents. The use of the latter also warrants intense monitoring of serum potassium levels. Clemastine and dimetindene should be avoided in patients with LQTS.

CONCLUSION

Patients with LQTS have a higher risk of life-threatening complications during the treatment of their allergic reactions because of the underlying disease and concomitant treatment with β-blockers. Treatment algorithms will certainly decrease these complications.

Underuse of epinephrine for the treatment of anaphylaxis: missed opportunities

Epinephrine is the only effective treatment for anaphylaxis but studies routinely show underutilization. This is especially troubling given the fact that fatal anaphylaxis has been associated with delayed administration of epinephrine. Many potential barriers exist to the proper use of epinephrine during an anaphylactic reaction. This article will explore both patient-and physician-related factors, as well as misconceptions that all contribute to the underuse of epinephrine for the treatment of anaphylaxis.

Epinephrine, auto-injectors, and anaphylaxis: Challenges of dose, depth, and device

OBJECTIVE

This review was undertaken to review epinephrine dosing, site and route of administration, focusing on special populations (patients weighing less than 15 kg, and obese patients); and to discuss storage and delivery of epinephrine in prehospital and hospital settings.

DATA SOURCES

Review of published literature.

STUDY SELECTION

Relevance.

RESULTS

The recommended 0.01-mg/kg (maximum 0.3-0.5 mg) epinephrine dose in anaphylaxis is based on limited pharmacokinetic data in healthy volunteers. No pharmacokinetic or pharmacodynamics studies involving patients in anaphylaxis have been published. When epinephrine auto-injectors (EAIs) are used in infants, the dose increasingly exceeds the recommended dose as weight decreases, although the clinical significance of this is unclear. Limited data indicate that the intramuscular route and lateral thigh site are superior. Ultrasound studies suggest that 0.15 EAI needles may be too long for many patients weighing less than 15 kg, and 0.3 mg EAI needles may be too short for obese patients weighing more than 30 kg. A newly available 0.1 mg EAI has a lower dose and shorter needle better suited to patients weighing 7.5 to 15 kg. In some medical settings, vials and syringes may provide a safe, efficient alternative with substantial cost savings over EAIs.

CONCLUSION

EAIs should be available in the community with doses and needle depths that meet the needs of all patients. More research on epinephrine pharmacodynamics are needed in children and adults in anaphylaxis, to better delineate what optimal doses should be. Optimizing epinephrine dose and delivery has the potential to improve anaphylaxis outcomes and prevent adverse events.

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.

The high molecular weight dipeptidyl peptidase IV Pol d 3 is a major allergen of Polistes dominula venom

Hymenoptera venom allergy can cause severe anaphylaxis in untreated patients. Polistes dominula is an important elicitor of venom allergy in Southern Europe as well as in the United States. Due to its increased spreading to more moderate climate zones, Polistes venom allergy is likely to gain importance also in these areas. So far, only few allergens of Polistes dominula venom were identified as basis for component-resolved diagnostics. Therefore, this study aimed to broaden the available panel of important Polistes venom allergens. The 100 kDa allergen Pol d 3 was identified by mass spectrometry and found to be a dipeptidyl peptidase IV. Recombinantly produced Pol d 3 exhibited sIgE-reactivity with approximately 66% of Polistes venom-sensitized patients. Moreover, its clinical relevance was supported by the potent activation of basophils from allergic patients. Cross-reactivity with the dipeptidyl peptidases IV from honeybee and yellow jacket venom suggests the presence of exclusive as well as conserved IgE epitopes. The obtained data suggest a pivotal role of Pol d 3 as sensitizing component of Polistes venom, thus supporting its status as a major allergen of clinical relevance. Therefore, Pol d 3 might become a key element for proper diagnosis of Polistes venom allergy.

Clinical features and treatment of pediatric patients with drug-induced anaphylaxis: a study based on pharmacovigilance data

We assessed the clinical features and treatment of pediatric patients with drug-induced anaphylaxis in clinical settings. Pediatric drug-induced anaphylaxis cases collected by the Beijing Pharmacovigilance Database from 2004 to 2014 were analyzed. A total of 91 cases were identified. Drug-induced anaphylaxis was primarily caused by antibiotics (53%). Children of 0-5 years were more likely to develop cyanosis symptoms than children of 13-17 years (OR = 5.14, 95%CI [1.74, 15.20], P = 0.002). Children of 13-17 years were more likely to develop hypotension than children of 6-12 years (OR = 11.79, 95%CI [2.28, 60.87], P = 0.002), and to manifest both neurological symptoms (OR = 3.56, 95%CI [1.26, 10.08], P = 0.015) and severe anaphylaxis than children of 0-5 years (OR = 15.46, 95%CI [1.85, 129.33], P = 0.002). Supratherapeutic doses of epinephrine were more likely with intravenous (IV) bolus (92%) in contrast to either intramuscular (IM) (36%, OR = 19.25, 95%CI [1.77, 209.55], P = 0.009) or subcutaneous (SC) injections (36%, OR = 19.80, 95% CI [1.94, 201.63], P = 0.005). Only 62 (68%) patients received epinephrine treatment as the first-line therapy.

CONCLUSION

This study demonstrates that antibiotics were the most common cause of pediatric drug-induced anaphylaxis. Children may present with different anaphylactic signs/symptoms based on age groups. Epinephrine is under-utilized and provider education on the proper management of drug-induced anaphylaxis is warranted. What is Known: • The most common causes of anaphylaxis in children are allergies to foods. Drugs are the second most common cause of pediatric anaphylaxis. • IM epinephrine is the recommended initial treatment of anaphylaxis. What is New: • Drug-induced anaphylaxis in pediatric patients has age-related clinical features. • IV bolus epinephrine was overused and associated with supratherapeutic dosing.

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.

Epinephrine auto-injector needle length: what is the ideal length?

PURPOSE OF REVIEW

The purpose of this manuscript is to review the literature on the clinical effects of the needle length of epinephrine (adrenaline) auto-injectors.

RECENT FINDINGS

Epinephrine has maximal pharmacodynamic effect within 10 min of intramuscular administration into the thigh. Prefilled epinephrine auto-injectors are designed for simplicity of use and safety. Auto-injectors are primarily used by patients in an unsupervised setting in cases of anaphylaxis. There are weight-appropriate doses of epinephrine available with auto-injectors that are prefilled, to prevent dosing errors, with 0.15, 0.30, and 0.50 mg amounts. In addition, needle lengths vary from 1.17 to 2.50 cm. The recommended needle lengths differ between adults and pediatric patients. In addition, the needle lengths differ between devices as well. There are concerns that the needle length may be too short in select obese patients. Yet, there are also concerns that the needle length may be too long in some patients. Factors that affect the depth of the injection, and therefore the pharmacokinetics of the drug, include not only the needle length but also the BMI, obesity, compression of soft tissue, and propulsion.

SUMMARY

Epinephrine auto-injectors have different needle lengths. Using the right device with appropriate needle length based on BMI, obesity, and employing the proper technique can improve the outcome in an anaphylactic event.