Bilateral facial palsy caused by bilateral masked mastoiditis.

Acquired simultaneous bilateral facial palsy caused by bilateral masked mastoiditis in a 25-month-old girl is reported. After the administration of antibiotics for 10 days for treatment of bilateral acute otitis media, overt signs of otitis media diminished as bilateral facial palsy ensued. For diagnosis of masked mastoiditis, brain magnetic resonance imaging was of significant value in our case. The findings in this case suggest that masked mastoiditis should be considered as a cause of bilateral facial palsy, as well as unilateral facial palsy.