What virus is responsible for Ramsey Hunt syndrome?

Ramsey Hunt syndrome is caused by the reactivation of the varicella zoster virus, which is the same virus that causes chickenpox. After a person recovers from chickenpox, the virus can remain dormant in the sensory nerves and may reactivate later in life, particularly in older adults or individuals with weakened immune systems. When reactivated in the facial nerve (cranial nerve VII), it leads to the characteristic symptoms of Ramsey Hunt syndrome, which include facial paralysis and a painful rash in the ear or mouth.

The link to varicella zoster virus is critical for understanding the pathophysiology of Ramsey Hunt syndrome because it highlights how conditions can arise from previous viral infections. This reactivation phenomenon is specific to varicella zoster and distinguishes it from other viruses that are known to cause different syndromes or illnesses.