Herpes zoster oticus is an uncommon manifestation of herpes zoster that affects the 8th cranial nerve ganglia and the geniculate ganglion of the 7th (facial) cranial nerve.
Herpes zoster (shingles) is reactivation of varicella-zoster virus infection. Risk factors for reactivation include immunodeficiency secondary to cancer, chemotherapy, radiation therapy, and HIV infection. Typically, the virus remains latent in a dorsal root ganglion, and reactivation manifests as painful skin lesions following a dermatomal distribution. However, rarely the virus remains latent in the geniculate ganglion and upon reactivation causes symptoms involving the 7th and 8th cranial nerves.
Symptoms and Signs of Herpes Zoster Oticus
Symptoms of herpes zoster oticus include
- Severe ear pain with vesicles in the ear
- Transient or permanent facial paralysis (resembling Bell palsy)
- Vertigo lasting days to weeks
- Hearing loss (which may be permanent or which may resolve partially or completely)
Vesicles occur on the pinna and in the external auditory canal along the distribution of the sensory branch of the facial nerve. Symptoms of meningoencephalitis (eg, headache, confusion, stiff neck) are uncommon. Sometimes other cranial nerves are involved.
Diagnosis of Herpes Zoster Oticus
- Clinical evaluation
Diagnosis of herpes zoster oticus usually is clinical. If there is any question about viral etiology, vesicular scrapings may be collected for direct immunofluorescence or for viral cultures, and MRI is done to exclude other diagnoses.
Treatment of Herpes Zoster Oticus
- Antivirals and corticosteroids
- Surgical decompression of the fallopian canal for complete facial paralysis
Although there is no reliable evidence that corticosteroids, antiviral drugs, or surgical decompression make a difference in herpes zoster oticus, they are the only possibly useful treatments. When used, corticosteroids are started with prednisone 60 mg orally once/day for 4 to 7 days, followed by gradual tapering of the dose over the next 2 weeks. Either acyclovir 800 mg orally 5 times/day or valacyclovir 1 g orally 2 times a day for 10 days may shorten the clinical course and is routinely prescribed for immunocompromised patients.
Vertigo is effectively suppressed with diazepam 2 to 5 mg orally every 4 to 6 hours. Pain may require oral opioids. Postherpetic neuralgia may be treated with amitriptyline.
Surgical decompression of the fallopian canal may be indicated if the facial palsy is complete (no visible facial movement), but must be performed within 2 weeks of onset of the facial paralysis to be effective. Before surgery, however, electroneurography is done and should show a >90% decrement.
Drugs Mentioned In This Article
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|amitriptyline||No US brand name|