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Background Data on the diagnostic properties of direct oral challenges without the use of skin tests in children with suspected amoxicillin allergy are sparse. Objective Assess the use of direct oral challenges. Methods A cohort study was conducted between March 2013 and March 2020, in Montreal and Winnipeg. All children referred with reported history of benign reactions (ie, limited to the skin with no mucosal lesions and no vesicles) to amoxicillin were recruited and a 2-step graded oral challenge (GOC) was conducted. Data were collected on demographic characteristics, clinical characteristics, and comorbidities. Eligible children were followed to assess reactions to subsequent use of amoxicillin and to assess the safety of cephalexin use in children with a positive GOC. Results Among 1914 children recruited, 1811 (94.6%) tolerated the GOC, 42 (2.2%) developed mild immediate reactions, and 61 (3.2%) developed mild nonimmediate reactions. Among 265 participants who had a negative GOC and reused amoxicillin, 226 (85.3%) reported tolerance and 39 (14.7%) had mild cutaneous reactions. Chronic urticaria (adjusted odds ratio [aOR], 1.16; 95% CI, 1.09-1.23) and an index reaction occurring within 5 minutes of exposure (aOR, 1.09; 95% CI, 1.04-1.14) were associated with immediate reactions during the GOC. Symptoms lasting longer than 7 days (aOR, 1.05; 95% CI, 1.02-1.09) and parental drug hypersensitivity (aOR, 1.04; 95% CI, 1.03-1.06) were associated with nonimmediate reactions. Among those reacting to the GOC, 12.5% reacted with mild cutaneous reactions to cephalexin challenge. Conclusions Direct GOCs are an accurate and safe confirmatory to establish true hypersensitivity among children reporting benign reactions to amoxicillin.

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.

BACKGROUND: Food protein-induced allergic proctocolitis (FPIAP) is an early and common manifestation of food allergy, yet its epidemiology and relationship to other allergic diseases remain unclear. OBJECTIVE: To prospectively define the incidence of FPIAP as it is being diagnosed clinically in the community and to identify factors associated with its development. METHODS: 1003 of 1162 eligible serial healthy newborn infants recruited from a single suburban pediatrics practice were followed prospectively for the diagnosis of FPIAP. Investigators reviewed each case to confirm pre-specified inclusion criteria, including documented gross or occult blood in the stool. RESULTS: 903 infants were analyzed (46% female, 89% term, 32% caesarian-section, 9% neonatal antibiotics). 153 cases met inclusion criteria, a cumulative incidence of 17%, while 63 (7%) had gross blood. Infants initially fed both breastmilk and formula were 61% less likely to develop FPIAP compared to those exclusively formula-fed (HR 0.39, P = .005). Breastmilk and formula at any point during the first 4 months was also associated with lower risk compared to exclusive formula or exclusive breastmilk (HR 0.44, P = .005; HR 0.62, P = .0497). Eczema (OR 1.5 [1.1, 2.2], P = .02) or a first degree relative with food allergies (OR 1.9 [1.2, 2.8], P = .005) were among risk factors for FPIAP development. CONCLUSION: The prospectively defined incidence of FPIAP when diagnosed clinically by community pediatricians without challenge is markedly higher than published estimates. Combination feeding of formula and breastmilk is associated with the lowest rate of FPIAP in this population.

Epinephrine is the first-line treatment for anaphylaxis. Despite this, there have been identified gaps in the management of anaphylaxis including infrequent or delayed use of epinephrine for acute allergic reactions, as well as inadequate epinephrine autoinjector (EAI) training, and prescription rates of these devices for patients at risk. This paper reviews new data, and new problems in recently published literature on EAIs. A database search was conducted for publications between January 2015 and February 2017 using keywords related to EAIs including their functionality and features, carriage, prescription rates, barriers, and side effects. Eligibility criteria included patients at risk for anaphylaxis, caregivers, and health care professionals. Experimental studies and observational studies were included. Of 1,737 potentially relevant articles, 19 were used for analysis. These articles addressed specific aspects of an EAI, including (1) information on features and functionality; (2) prescriptions; (3) training on their use; and (4) carriage and use at the time of reaction by patients, schools, camps, emergency departments, and paramedics. Our review highlights that existing gaps in anaphylaxis management remain unaddressed. Patient needs are largely unmet, and very few studies are being designed to clarify and instill best practice, and to determine how to increase adherence to existing anaphylaxis guidelines through integrated knowledge translation strategies.

Studies suggest that individuals of low education and/or income, new Canadians (immigrated10 years ago), and individuals of Aboriginal identity may have fewer food allergies than the general population. However, given the difficulty in recruiting such populations (hereafter referred to as vulnerable populations), by using conventional survey methodologies, the prevalence of food allergy among these populations in Canada has not been estimated.To estimate the prevalence of food allergy among vulnerable populations in Canada, to compare with the nonvulnerable populations and to identify demographic characteristics predictive of food allergy.By using 2006 Canadian Census data, postal codes with high proportions of vulnerable populations were identified and households were randomly selected to participate in a telephone survey. Information on food allergies and demographics was collected. Prevalence estimates were weighted by using Census data to account for the targeted sampling. Multivariable logistic regression was used to identify predictors of food allergy.Of 12,762 eligible households contacted, 5734 households completed the questionnaire (45% response rate). Food allergy was less common among adults without postsecondary education versus those with postsecondary education (6.4% [95% CI, 5.5%-7.3%] vs 8.9% [95% CI, 7.7%-10%]) and new Canadians versus those born in Canada (3.2% [95% CI, 2.2%-4.3%] vs 8.2% [95% CI, 7.4%-9.1%]). There was no difference in prevalence between those of low and of high income or those with and without Aboriginal identity.Analysis of our data suggests that individuals of low education and new Canadians self-report fewer allergies, which may be due to genetics, environment, lack of appropriate health care, or lack of awareness of allergies, which reduces self-report.

Background Studies suggest knowledge gaps about epinephrine use and vaccination of persons with egg allergy. Objective We compared the perception of Canadian allergists and nonallergists on issues related to epinephrine use and vaccination of persons with egg allergy. Methods Canadian allergists, pediatricians, general practitioners/family physicians and emergency room physicians were recruited through medical associations and surveyed on these issues. Multivariate logistic regression models were used to identify determinants of specific responses. Results One-hundred fourteen allergists and 613 nonallergists participated. For most issues with accepted best practices, allergists were more likely to adhere to recommendations. Allergists versus nonallergists were more likely to recommend intramuscular epinephrine for anaphylaxis (odds ratio [OR] = 3.8; 95% CI, 1.43-10.11). Older physicians (OR = 0.98; 95% CI, 0.97-0.99), Canadian-Paediatric-Surveillance-Program participants (OR = 0.48; 95% CI, 0.24-0.96), family physicians (OR = 0.39; 95% CI, 0.16-0.96), and general practitioners (OR = 0.14; 95% CI, 0.04-0.52) were less likely to recommend intramuscular use. However, in severe anaphylaxis, >25% of both groups would not give epinephrine for patients presenting with breathing difficulties or hypotension. Use of epinephrine for severe anaphylaxis was less likely in older physicians (OR = 0.97; 95% CI, 0.95-0.99), female physicians (OR = 0.60; 95% CI, 0.39-0.89), and those practicing in Ontario (OR = 0.56; 95% CI, 0.36-0.86), Manitoba (OR = 0.42; 95% CI, 0.19-0.90), or Nova-Scotia (OR = 0.31; 95% CI, 0.12-0.78). Allergists (OR = 6.22; 95% CI, 3.60-10.72) and physicians treating mainly children (OR = 3.41; 95% CI, 1.87-6.25), or practicing in Quebec (OR = 1.68; 95% CI, 1.12-2.55) were more likely to recommend measles-mumps-rubella vaccination in a community facility. Conclusion Knowledge gaps about mode and indications for epinephrine administration and vaccination policies need to be addressed in future education programs to ensure prompt epinephrine use and to avoid unnecessary restriction of vaccines.