Herpes zoster is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute (short-lived) illness chickenpox which generally occurs in children and young people. Once an episode of chickenpox has resolved, Varicella zoster virus can become latent in the nerve cell bodies and less frequently in non-neuronal satellite cells of dorsal root, cranial nerve or autonomic ganglion,without causing any symptoms.Years or decades after a chickenpox infection, the virus may break out of nerve cell bodies and travel down nerve axons to cause viral infection of the skin in the region of the nerve. The virus may spread from one or more ganglia along nerves of an affected segment and infect the corresponding dermatome causing a painful rash.Although the rash usually heals within two to four weeks, some sufferers experience residual nerve pain for months or years, a condition called postherpetic neuralgia.Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster in that same dermatomic area.Treatment options for PHN include antidepressants, anticonvulsants (such as gabapentin or pregabalin) and topical agents such as lidocaine patches or capsaicin lotion. Opioid analgesics may also be appropriate in many situations.
Ramsay Hunt syndrome type 2 also known as herpes zoster oticus is a disorder that is caused by the reactivation of pre-existing herpes zoster virus in a nerve cell bundle in the head (the geniculate ganglion).The neurons in this ganglion are responsible for the movements of facial muscles, the touch sensation of a part of ear and ear canal, the taste function of the frontal two-thirds of the tongue, and the moisturization of the eyes and the mouth.The symptoms and signs include acute facial nerve paralysis, pain in the ear, taste loss in the front two-thirds of the tongue, dry mouth and eyes, and eruption of a erythematous vesicular rash in the ear canal, the tongue, and/or hard palate.
