Herpes Zoster Oticus

Herpes zoster oticus usually accounts for 1% of all the zoster infection and manifests as cutaneous vesicular eruption of the internal or external canal and pinna and is characterized by severe ear pain, a rash around the ear and usually associated with facial paralysis so called Ramsay Hunt Syndrome which was coined after the neurologist James Ramsay Hunt who had described the disease in 1907. He suggested that the disease resulted from a geniculate ganglionitis after reactivation of surviving viruses (VZV), a theory that recently proved true for many cases examined. Ramsay Hunt syndrome is considered as a rare complication of the varicella zoster virus and is characterized by peripheral facial palsy resulting from facial and auditory nerves injury during VZV infection. In addition, Ramsay Hunt syndrome may be also be associated with cranial nerves V, VI, IX, X and XII [1]

Facial palsy as a most important clinical symptom may be related to a necrotizing inflammation of the ganglion. However, sometimes it may occur without the involvement of ganglion or may be due to neuritis or perineuritis of nerve itself. Histological studies in temporal bones of decedents within the course of the disease revealed various perineural, perivascular or intraneural infiltration with different degrees of tissue destruction. Secondary effects like swelling by edema and/or hemorrhage may cause compression of the nerve within its bony canal. In those areas blood circulation may severely be impaired, leading to additional damage. Hearing loss, vertigo and tinnitus which are often seen is caused by inflammation of the inner ear structures.

Generally, herpes zoster oticus is considered as a disease of elderly and immunocompromised individuals. However, it may also be seen in young adults during stressful condition.[2] Even in children with acute peripheral facial paralysis, varicella zoster virus reactivation is considered an important factor [3]. Surgical manipulation is sometimes considered as a cause of outbreak of the disease. The disease is often unilateral and bilateral involvement is very rare but may be seen in immunocompromised individuals.

Although clinical course may vary from individual to individuals, general a prodromal period with fatigue and other sickness-like symptoms (approximately 7–14 days) is followed by a phase of erupting herpetiform lesions. Erythematous maculopapular lesions around or on the auricle (most often in the concha or the superficial part of the outer ear canal) soon vesiculate and sometimes turn to ulcers. Vesicles in the buccal mucosa of the corresponding sides or oropharynx can also be seen in rare cases. There may be slightly increase in body temperature and moderate to severe pain in the ear and surrounding which may persist even after the resolution of the lesions. Lesions usually turn dry and crust out after 1 week. Regional lymphadenopathy may be common findings. In about 8% to 10% of the patients zoster oticus may occur without the classical zoster rash also known as zoster sine herpete. [4]

Herpes zoster oticus accounts for about 10% all the facial palsy. Facial nerve involvement is seen in about 70% of the zoster oticus patients. Facial palsy is usually seen after the eruption of rash, proceeding from mild facial weakness to complete unilateral paralysis. If untreated the prognosis is very poor and chances of recovery is 70% in partial paralysis and only 10% in complete paralysis.[5]

References:
1. Sun WL, Yan JL, Chen LL: Ramsay Hunt syndrome with unilateral polyneuropathy involving cranial nerves V, VII, VIII, and XII in a diabetic patient. Quintessence Int. 2011 Nov-Dec;42(10):873-7.
2. Meister W, Neiss A, Gross D, Doerr HW, Höbel W, Malin JP, von Essen J, Reimann BY, Witke C, Wutzler P: Demography, symptomatology and course of disease in ambulatory zoster patients. Intervirology 1998;41:272–277.
3. Furuta Y, Ohtani F, Aizawa H, Kukuda S, Kawabata H, Bergstrom T: Varicella-zoster virus reactivation is an important cause of acute peripheral facial paralysis in children. Pediatr Inf Dis J 2005;24:97–101.
4. Rudra T: Zoster sine herpete. Br J Clin Pract 1990;44:284
5. 21 Devriese PP, Moesker WH: The natural history of facial paralysis in herpes zoster. Clin Otolaryngol 1988;13:289–298.