Risk of malignancy following emergency department Bell's palsy diagnosis in children

Objective: To quantify the risk of malignancy following the emergency department (ED) diagnosis of Bell's Palsy (BP) using a large retrospective cohort. Study design: We performed a cohort study using the Pediatric Health Information System database. We included all children (6 months – 17 years) from 2011 to 2020 with an ED diagnosis of BP. We excluded children with previous neurologic chronic condition or malignancy diagnosed during or prior to the index visit. Our primary outcome was diagnosis of malignancy within 60 days following the index ED visit. We compared clinical characteristics between children with and without new-onset malignancy. Results: Of 12,272 encounters for BP, 41 had a new oncologic diagnosis within 60 days (0.33%, 95% confidence interval [CI]: 0.25–0.45%). Median time to oncologic diagnosis was 22 days. Primary CNS malignancy (59%) and leukemia (17.1%) were the most common diagnoses. Younger children had a higher incidence of new oncologic diagnosis compared with older children. Incidences were 0.68% (95% CI 0.36–1.3%), 0.70% (95% CI 0.38–1.3%), 0.26% (95% CI 0.15–0.47%), and 0.21% (95% CI 0.12–0.37%) for children aged <2 years, 2–5 years, 6–11 years, and 12–17 years respectively. Conclusions: We found a small but potentially clinically significant rate of new-onset oncologic diagnosis within 60 days after BP diagnosis in the ED, especially in children younger than 5 years. Further studies of the diagnostic utility of laboratory testing or neuroimaging and the risk of empiric steroids in children with BP are needed.