Anaphylaxis in an emergency care setting: a one year prospective study in children and adults.

BACKGROUND: Current data on anaphylaxis is based on retrospective and register based studies. The objective of this study was to describe the epidemiology of anaphylaxis in a 1 year prospective study at the emergency care setting, Odense University Hospital, Denmark (2013-2014). METHODS: Prospective study at the emergency care setting, Odense University Hospital, Denmark (2013-2014). To identify anaphylaxis cases, records from all patients with clinical suspicion on anaphylaxis or a related diagnosis according to the International Classification of Diseases 10 and from patients treated at the emergency care setting or at prehospital level with adrenaline, antihistamines or glucocorticoids were reviewed daily. The identified cases were referred to the Allergy Center, where a standardized interview regarding the anaphylactic reaction was conducted. International guidelines were applied for the assessment of anaphylaxis and its pharmacological treatment. Severity of the anaphylactic reaction was evaluated according to Sampson's severity score. RESULTS: We identified 180 anaphylactic patients. Anaphylaxis represented 0.3%-0.4% of all contacts in the emergency care setting with an incidence rate of 26.8 cases per 100,000 person years (95% CI: 14.3-45.8) in children and 40.4 cases per 100,000 person years (95% CI: 32.8-49.3) in adults. Moderate to severe anaphylaxis was registered in 96% of the cases. Skin (96%) and respiratory (79%) symptoms were the most frequent registered, but 7% of cases in adults occurred without skin manifestations. The most common elicitor in children was food (61%), while drugs (48%) and venom (24%) were the main suspected elicitors in adults. Adrenaline was administered in 25% of the cases and it was significantly less administered than glucocorticoids (83%) and antihistamines (91%). The mortality rate during our study period was 0.3 cases per 100,000 person years. DISCUSSION: This is one of the first prospective studies on the epidemiology of anaphylaxis in children and adults, where the patients are identified not only based on diagnosis codes but also on history, symptoms and treatment and thereafter classified according to international diagnosis criteria for anaphylaxis. A limitation of this study is that only patients who gave consent to participate in the study were included. Furthermore, patients may have attended other hospitals during the study period. Therefore, the estimates are minimum figures. CONCLUSION: The prospective study design with a broad search profile yield a higher incidence than previously reported. Adrenaline was administered in a low proportion of the patients with moderate to severe anaphylaxis. Standardized diagnosis criteria among physicians treating anaphylaxis are needed.

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

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