Herpes zoster oticus is a herpes zoster virus infection of the clusters of nerve cells (ganglia) that control the nerves responsible for hearing and balance (8th cranial nerve) and for facial movement (7th cranial nerve).
Herpes zoster (shingles) is infection that results from a reactivation of the varicella-zoster virus, which causes chickenpox. After an episode of chickenpox, the virus lies dormant in nerve roots and can be reactivated, travelling down the nerve fibers to the skin, where it causes painful sores. Most often the cause of reactivation is unknown, but sometimes it occurs when the immune system is weakened, for example, by cancer, AIDS, or certain medications.
Herpes zoster oticus occurs when the herpes zoster virus is reactivated in the 7th (facial) and 8th (auditory or vestibulocochlear) cranial nerves. The 7th cranial nerve controls some muscles of the face. The 8th cranial nerve controls hearing and balance.
