Epidemiologic and clinical features of Bell's palsy among children in Northern California.

BACKGROUND Bell's palsy (BP) is an acute, idiopathic, and usually unilateral paralysis of the facial nerve. Large population-based studies of BP among children are lacking. We determined epidemiologic and clinical features of BP among children enrolled in a large integrated health care delivery system. METHODS From 2001 through 2006, all children ≤18 years of age diagnosed with BP within the population of Kaiser Permanente Northern California were identified using the International Classification of Diseases, 9th Revision, code 351.0. All cases were adjudicated by an otolaryngologist and categorized as definite, probable, or rejected. Using chart abstraction forms, epidemiologic and clinical features of BP were determined. RESULTS Of a total of 977 cases initially identified, 822 (84.1%) were adjudicated as a definite or probable case. The overall incidence rate of BP during the study period was 18.8 (95% CI 17.6-20.2) per 100,000 person-years. The incidence rate increased by age and was higher in females than males across all age strata. There was no evidence for a seasonal pattern in the occurrence of BP (p for trend = 0.81). CONCLUSIONS BP among children may be more common than previously recognized.