Frequency and impact of paediatric acute-onset neuropsychiatric syndrome/paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections diagnosis in Canada.

Objectives: This study aims to estimate the prevalence of the PANS/PANDAS diagnostic label in Canada and describe its impact on families, patients, and health care.

Methods: Through the Canadian Paediatric Surveillance Program (CPSP), a monthly form was distributed to paediatricians from December 2019 to November 2021, requesting reports of children who received the diagnostic label of PANS/PANDAS between the ages of 3 and 18 years seen in the previous month. Descriptive and association statistical analyses were performed.

Results: Eighty-four cases (57% female, median age of symptom onset 7.8 years interquartile range [IQR] = 5) who received the diagnostic label of PANS/PANDAS were included. Prevalence was found to be 1 in 60,155 (0.0017%). Core diagnostic criteria for PANS/PANDAS (obsessive-compulsive disorder or tics or acute food refusal) were not present in 12% of cases (10/84). Only 22% reported sudden symptom onset. Infection was associated with symptom onset or exacerbation in less than one-third of cases. The majority exhibited two or more neuropsychiatric symptoms (95%). There was significant health care utilization and symptom burden amongst cases. There was a significant difference in the certainty of diagnosis between physicians and families (P < 0.05).

Conclusions: PANS/PANDAS diagnoses, while rare, significantly impact children, families, and the health care system. Diagnostic uncertainty underscores the challenges professionals and families face in accessing effective care, emphasizing the need for education and evidence-based clinical practice guidelines.