Search

Anaphylaxis is an acute systemic and potentially fatal allergic reaction. In this study, we evaluated trends in yearly rates of anaphylaxis in a pediatric Emergency Department (ED) in Montreal, Canada.A prospective and retrospective recruitment process was used to find families of children who had presented with anaphylaxis at the Montreal Children's Hospital between April 2011 and April 2021. Using a uniform recruitment form, data were collected. Anaphylaxis patterns were compared to clinical triggers using descriptive analysis.Among 830,382 ED visits during the study period, 2726 (26% recruited prospectively) presented with anaphylaxis. The median age was 6 years (IQR: 0.2, 12.00), and 58.7% were males. The relative frequency of anaphylaxis cases doubled between 2011-2015, from 0.22% (95% CI, 0.19, 0.26) to 0.42 March 2020, the total absolute number of anaphylaxis cases and relative frequency declined by 24 cases per month (p0.05) and by 0.5% of ED visits (p0.05).The rate of anaphylaxis has changed over the years, representing modifications in food introduction strategies or lifestyle changes. The observed decrease in the frequency of anaphylaxis presenting to the ED during the COVID pandemic may reflect decreased accidental exposures with reduced social gatherings, the school closed, and reluctance to present to ED.

Background Serum sickness–like reactions (SSLRs) are defined by the presence of rash (primarily urticaria) and joint complaints (arthralgia/arthritis) that are believed to occur due to a non–IgE-mediated response to medications. However, similar reactions can occur due to viral infections, and it can be difficult to distinguish between the two. This may lead to unnecessary avoidance of the culprit antibiotic. Objective We aimed to evaluate children presenting with suspected SSLRs through a graded oral challenge (GOC). Methods All children referred to the Montreal Children's Hospital for potential antibiotic allergy (β-lactam or other antibiotics) and a clinical presentation compatible with SSLR were recruited for the study between March 2013 and February 2020. A standardized survey with questions on treatment, symptoms, and associated factors was completed, and a GOC (10% and subsequently 90% of the oral antibiotic dose) was conducted. Patients with a negative GOC were contacted annually to query on subsequent antibiotic use. Results Among 75 patients presenting with suspected SSLRs, the median age was 2.0 years and 46.7% were males. Most reactions were attributed to amoxicillin. Among the 75 patients, 2.7% reacted immediately (within 1 hour) to a GOC and 4.0% had a nonimmediate reaction. Of the 43 patients successfully contacted, 20 reported subsequent culprit antibiotic use of whom 25.0% had a subsequent mild reaction (macular/papular rash). Conclusions This is the first and largest pediatric study to assess SSLR using a GOC. Our findings suggest that using a GOC is safe and appropriate for differentiating between β-lactam-induced SSLR and viral exanthem in this population.