The primary pathophysiology is located in the geniculate ganglion of the facial nerve. Geniculate ganglion is found to be affected by human herpes virus type 3 i.e. (varicella zoster virus). Varicella zoster virus have been identified from tears of these patients by polymerase chain reaction. Infact varicella zoster virus have also been identified from tears of patients with bells palsy.
These patients have deep seated pain in the affected ear associated with vertigo, tinnitus, ipsilateral transient hearing loss and lower motor neuron type of facial palsy. These symptoms develop due to involvement of the geniculate ganglion of the facial nerve located near the petrous pyramid portion of the temporal bone. The site of rash varies from patient to patient due to individual variations in the areas supplied by the nervous intermedius of wrisburg (sensory branch of facial nerve). Rashes may be present in the anterior 2/3 of the tongue, soft palate, external auditory canal and the pinna.
