Evidence suggests a prodromal phase in multiple sclerosis (MS), with increased health care use preceding the first demyelinating event (FDE). Although prior studies have explored this in adults, limited data exist for pediatric cases. We aimed to analyze health care utilization and prodromal symptoms in the two years before FDE in patients with pediatric-onset MS (POMS).

From 122 patients at the Pediatric Multiple Sclerosis & Demyelinating Diseases Center at Washington University School of Medicine from 2011 to 2021, 37 POMS cases were identified. Of these, 21 with at least two years of records preceding FDE were included. Retrospective analysis covered symptoms and health care utilization in the two-year period before FDE, including ambulatory visits, hospital admissions, and office calls.

Patients showed increased health care utilization in the year preceding FDE (period B; 96 interactions) compared with the prior year (period A; 77 interactions) and an increase in the percentage of neurology-related encounters (P < 0.001). There was an increase in all office calls from period A to period B (P = 0.01). Neurological complaints included headaches (28.6%), visual (19.0%), sensory (14.3%), and balance (14.3%) in the two years before FDE, and 28.6% of patients presented for psychiatric complaints. Common non-neurological complaints included infection, dermatologic, and musculoskeletal issues and injury.

Our POMS cohort showed increased health care use before FDE, consistent with population-based data. This study emphasizes diverse symptoms in prodromal POMS, with headaches being the most common neurological symptom in the two-year period before FDE.