Managing anaphylaxis: Epinephrine, antihistamines, and corticosteroids: More than 10 years of Cross-Canada Anaphylaxis REgistry data

Symptomatology and Management of Adult Anaphylaxis according to Trigger: A Cross-Sectional Study

INTRODUCTION

Anaphylaxis is an acute life-threatening allergy, most commonly provoked by food, venom, or drugs. There is limited data regarding differences in symptomatology between anaphylaxis provoked by different triggers. This study aimed to assess sociodemographic characteristics, clinical symptoms, and management of anaphylaxis, according to triggers in adults.

METHODS

We conducted a cross-sectional study recruiting adult patients with anaphylactic reactions across 8 emergency departments (EDs) and 1 electronic medical service (EMS) in Canada. Univariate and multivariate regression models were used to evaluate symptoms involving all patients with the outcome of drug-induced anaphylaxis (DIA), venom-induced anaphylaxis (VIA), peanut-induced anaphylaxis (PIA), shellfish-induced anaphylaxis, tree-nut induced anaphylaxis (TIA) and nut-induced anaphylaxis (NIA). We assessed comorbidities associated with severe reactions, stratified by triggers listed above. Additionally, we evaluated the association of each trigger with treatment through regression models involving all patients with medications used as outcome and anaphylaxis triggers used as independent variables.

RESULTS

From April 2011 to November 2023, 1,135 adults presenting with anaphylaxis to EDs were recruited. The median age was 35.5 (interquartile range 25.3-51.1). Most of the patients presented with FIA (50.3%). Regarding symptomatology, hypotension was more likely associated with DIA (aOR = 1.20, 95% CI = 1.11-1.30, p < 0.01). When adjusted for age at reaction and male sex, alcohol was more likely associated (aOR = 1.51, 95% CI = 1.04-2.19, p = 0.035) with NIA. Regarding management, TIA was more likely associated with inpatient epinephrine (aOR = 2.05, 95% CI = 1.16-3.64, p = 0.014). DIA was less likely associated with outpatient antihistamine (aOR = 0.68, 95% CI = 0.48-0.89, p < 0.01) whereas TIA was more likely associated with outpatient antihistamine (aOR = 1.81, 95% CI = 1.03-3.19, p = 0.040).

CONCLUSION

Our study underscores associations between specific triggers, clinical manifestations and managements, such as the potential link between TIA and throat tightness and hypotension and VIA. Identifying such associations can aid with the prompt diagnosis of anaphylaxis in patients presenting to the ED, leading to swifter treatment initiation and improving overall outcomes.

Time trends in the epidemiology of food allergy in England: an observational analysis of Clinical Practice Research Datalink data

BACKGROUND

Estimates for the prevalence of food allergy vary widely, with a paucity of data for adults. The aim of this analysis was to report trends in the incidence and prevalence of food allergy in England, using a national primary care dataset.

METHODS

We analysed data from Clinical Practice Research Datalink between 1998 and 2018, with linked data to relevant hospital encounters in England. The main outcomes were incidence and prevalence of food allergy, according to three definitions of food allergy: possible food allergy, probable food allergy, and probable food allergy with adrenaline autoinjectors prescription. We also evaluated the difference in proportion of patients prescribed adrenaline autoinjectors by English Index of Multiple Deprivation (IMD), age, and by previous food anaphylaxis, and explored differences in patient encounters (general practice vs emergency department setting).

FINDINGS

7 627 607 individuals in the dataset were eligible for inclusion, of whom 150 018 (median age 19 years [IQR 4-34]; 82 614 [55·1%] female and 67 404 [44·9%] male) had a possible food allergy. 121 706 met diagnostic criteria for probable food allergy, of whom 38 288 were prescribed adrenaline autoinjectors. Estimated incidence of probable food allergy doubled between 2008 and 2018, from 75·8 individuals per 100 000 person-years (95% CI 73·7-77·9) in 2008 to 159·5 (156·6-162·3) individuals per 100 000 person-years in 2018. Prevalence increased from 0·4% (23 399 of 6 432 383) to 1·1% (82 262 of 7 627 607) over the same period and was highest in children under 5 years (11 951 [4·0%] of 296 406 in 2018) with lower prevalence in school-aged children (from 11 353 [2·4%] of 473 597 in 2018 for children aged 5-9 years to 6896 [1·7%] of 404 525 for those aged 15-19 years) and adults (42 848 [0·7%] of 5 992 454 in 2018). In those with previous food anaphylaxis, only 2321 (58·3%) of 3980 (975 [64·0%] of 1524 children and young people and 1346 [54·8%] of 2456 adults) had a prescription for adrenaline autoinjector. Adrenaline autoinjectors prescription was less common in those resident in more deprived areas (according to IMD). In the analysis of health-care encounters, 488 604 (97·1%) of 503 198 visits recorded for food allergy occurred in primary care, with 115 655 (88·4%) of 130 832 patients managed exclusively in primary care.

INTERPRETATION

These estimates indicate an important and increasing burden of food allergy in England. Our findings that most patients with food allergy are managed outside the hospital system, with low rates of adrenaline autoinjector prescription in those with previous anaphylaxis, highlight a need to better support those working in primary care to ensure optimal management of patients with food allergy.

FUNDING

UK Food Standards Agency and UK Medical Research Council.

Milk-induced anaphylaxis among children presenting to Canadian emergency departments

BACKGROUND

Cow's milk is one of the most common and burdensome allergens in pediatrics, and it can induce severe anaphylactic reactions in children. However, data on cow's milk-induced anaphylaxis are sparse.

OBJECTIVE

To describe the epidemiology of pediatric cow's milk-induced anaphylaxis and to determine risk factors for repeat emergency department (ED) epinephrine administration.

METHODS

Between April 2011 and May 2023, data were collected on children with anaphylaxis presenting to 10 Canadian EDs. A standardized form documenting symptoms, triggers, treatment, and outcome was used. Multivariate logistic regression was used.

RESULTS

Of 3118 anaphylactic reactions, 319 milk-induced anaphylaxis cases were identified (10%). In the prehospital setting, 54% of patients with milk-induced anaphylaxis received intramuscular epinephrine. In those with milk-induced anaphylaxis, receiving epinephrine before presenting to the ED was associated with a reduced risk of requiring 2 or more epinephrine doses in the ED (adjusted odds ratio, 0.95 [95% CI, 0.90-0.99]). Children younger than 5 years of age were more likely to experience a mild reaction compared with that in older children, who experienced a moderate reaction more often (P < .0001). Compared with other forms of food-induced anaphylaxis, children presenting with milk-induced anaphylaxis were younger; a greater proportion experienced wheezing and vomiting, and less experienced angioedema.

CONCLUSION

Prehospital epinephrine in pediatric milk-induced anaphylaxis is underused; however, it may decrease risk of requiring 2 ED epinephrine doses. Milk-induced anaphylaxis in children younger than 5 years of age may be less severe than in older children. Wheezing and vomiting are more prevalent in milk-induced anaphylaxis compared with that of other foods.