Bell's palsy: an update on idiopathic facial paralysis.

Patients with Bell's palsy, or idiopathic facial paralysis, present sporadically in the primary care setting. New evidence implicates reactivated herpes simplex virus (HSV) as the etiologic agent in greater than 70% of cases diagnosed as Bell's palsy. Careful evaluation of the patient with facial paralysis, including history, physical examination, and diagnostic assessment, may mandate the expeditious treatment of facial paralysis to prevent faulty nerve regeneration during the recovery period. Using the results of an objective tool for grading resting facial symmetry, symmetry of voluntary movement, and synkinesis can provide a quantitative measurement for decision making. These data are also useful in documenting progression or regression of the patient's facial paralysis. Administration of acyclovir with prednisone improves the recovery of complete facial functioning following an episode of Bell's palsy. During the acute and convalescent stages, the eye on the affected side must be protected until function is restored to the facial nerve. Residual effects of Bell's palsy lasting more than 6 months may indicate another diagnosis and the need to refer the patient to a specialist.