Herpes zoster oticus
HERPES ZOSTER OTICUS
HERPES ZOSTER OTICUS DEFINITION
Herpes zoster oticus, also called Ramsay Hunt Syndrome or Ramsay Hunt Syndrome type II, is a common complication of shingles. Shingles is an infection caused by the varicella-zoster virus, which is the virus that causes chickenpox. Shingles occurs in people who have had chickenpox and represents a reactivation of the dormant varicella-zoster virus. Herpes zoster oticus, which is caused by the spread of the varicella-zoster virus to facial nerves, is characterized by intense ear pain, a rash around the ear, mouth, face, neck, and scalp, and paralysis of facial nerves. Other symptoms may include hearing loss, vertigo (abnormal sensation of movement), and tinnitus (abnormal sounds). Taste loss in the tongue and dry mouth and eyes may also occur.
HERPES ZOSTER OTICUS CAUSES
Herpes zoster oticus is 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―see see Shingles) is infection that results from a reactivation of the varicella-zoster virus, the virus that causes chickenpox. This 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 drugs.
Herpes zoster oticus occurs when the virus occupies the 7th and 8th cranial nerves. These nerves control hearing, balance, and some muscles of the face. Thus herpes zoster oticus causes severe ear pain, temporary or permanent paralysis of the face (similar to Bell palsy―see Bell Palsy), vertigo (a false sensation of moving or spinning) that lasts days to weeks, and hearing loss (which may be permanent or which may resolve partially or completely). Fluid-filled blisters (vesicles) occur on the outside of the ear (pinna) and in the ear canal. People rarely have headache, confusion, or a stiff neck. Sometimes other cranial nerves are affected.
HERPES ZOSTER OTICUS PATHOPHYSIOLOGY
Ramsay Hunt syndrome is defined as VZV infection of the head and neck that involves the facial nerve, often the seventh cranial nerve (CN VII). Other cranial nerves (CN) might be also involved, including CN VIII, IX, V, and VI (in order of frequency). This infection gives rise to vesiculation and ulceration of the external ear and ipsilateral anterior two thirds of the tongue and soft palate, as well as ipsilateral facial neuropathy (in CN VII), radiculoneuropathy, or geniculate ganglionopathy.
VZV infection causes 2 distinct clinical syndromes. Primary infection, also known as varicella or chickenpox, is a common pediatric erythematous disease characterized by a highly contagious generalized vesicular rash. The annual incidence of varicella infection has significantly declined after the introduction of mass vaccination programs in most countries of the world.
After chickenpox, VZV remain latent in neurons of cranial nerve and dorsal root ganglia. Subsequent reactivation of latent VZV can result in localized vesicular rash, known as herpes zoster. VZV infection or reactivation involving the geniculate ganglion of CN VII within the temporal bone is the main pathophysiological mechanism of Ramsay Hunt syndrome.
HERPES ZOSTER OTICUS SYMPTOMS
The two main signs of Ramsay Hunt syndrome are:
- A painful red rash with fluid-filled blisters on, in and around one ear
- Facial weakness or paralysis on the same side as the affected ear
Usually, the rash and the facial paralysis develop at the same time. But in some cases, the rash will occur before the facial paralysis or the paralysis before the rash. Sometimes the rash never materializes.
If you have Ramsay Hunt syndrome, you might also experience:
- Ear pain
- Hearing loss
- Ringing in your ears (tinnitus)
- Difficulty closing one eye
- A sensation of spinning or moving (vertigo)
- A change in taste perception or loss of taste
HERPES ZOSTER OTICUS DIAGNOSIS
Four cases of Herpes Zoster Oticus (HZO) with facial paralysis are presented. HZO is a Herpes Zoster viral infection of the Geniculate Ganglion of the facial nerve. It presents classically with severe otalgia, a vesicular rash in the Concha or on the Pinna of the affected ear in association with a lower motor neurone lesion of the homolateral facial nerve. There also may be labyrinthine symptoms, sensineural hearing loss and vesicular eruptions in the regions supplied by the vagus and glossopharyngeal nerves viz, hypopharynx and oropharynx as these nerves communicate with the facial nerve. Treatment consists of Acyclovir. One reference in the past refers to a clustering of the condition and its predisposition for females. Interestingly all cases presented were referred with incorrect diagnoses.
HERPES ZOSTER OTICUS TREATMENT
Some cases of herpes zoster oticus do not require treatment. When treatment is needed, medications such as antiviral drugs or corticosteroids may be prescribed. Vertigo may be treated with the drug diazepam.