Prevalence of Physician-Reported Food Allergy in Canadian Children

Food allergy prevalence data have largely been derived from self-report, and estimates vary.

Determine the prevalence of physician-reported food allergy in children using electronic medical record data from the Canadian Primary Care Sentinel Surveillance Network (CPSSN).

This was a retrospective cohort study using the CPCSSN repository, Canada's only primary care practice-based surveillance system. Machine learning algorithms were applied to assess for food allergy documentation. Demographic information, chronic diseases of interest, prescribed medications, and health behaviors from the CPCSSN repository were identified.

The prevalence of physician-reported food allergy in Canadian children was 2.53% (95% CI, 2.48%-2.59%). The most common food allergies documented were peanut (0.8% of children), tree nut (0.6%), cow's milk (0.4%), egg (0.3%), fruit (0.2%), finned fish (0.2%), and shellfish (0.2%). Among children with food allergy, only 33.7% had an epinephrine autoinjector prescription. In logistic regression analysis, children with food allergy were more likely to have an atopic comorbidity (odds ratio [OR], 2.20; 95% CI, 2.06-2.35) and less likely to be obese than children without food allergies (OR, 0.84; 95% CI, 0.78-0.90). In the age- and sex-adjusted models, patients with food allergy were significantly more likely to have a psychiatric morbidity, specifically: attention deficit/hyperactivity disorder (OR, 1.81; 95% CI, 1.66-1.96), autism (OR, 1.89; 95% CI, 1.63-2.19), and depression (OR, 1.17; 95% CI, 1.02-1.35).

Our study is the first to estimate national physician-reported prevalence of food allergy, and demonstrates a lower rate than that based on self-report. Further studies into the association of food allergy and psychiatric comorbidities (attention deficit/hyperactivity disorder, autism, depression) and the association of food allergy and obesity are needed.