Herpes Zoster

– The information has been reviewed by Dr. Wong Tin Yau, Andrew

There were two patients coming in for medical consultation recently: one was an elderly at 70s with inflaming and serum leaking vesicles appearing on left cheek, ear, and eye; another was a 40-year-old man reported pain in stomach and back while rash around abdomen was found when he was hospitalized. Both are confirmed cases of herpes zoster. While the man was stressed due to recent decease of his mother, the elderly had a weak immune system. Both of them had demonstrated most common triggers of herpes zoster. On average, one out of four persons would experience herpes zoster at least once in their lifetime.

Risk Factors of Herpes Zoster

“Snake infection” is a term in the Chinese community to describe herpes zoster. What contributes to a herpes zoster infection? Many of us were infected by varicella virus during childhood. After recovering from varicella infection, its virus remains latent in the dorsal root ganglion. The virus will be reactivated when one is aged, overworked, having insufficient rest, or becoming immunosuppressed, for example, due to AIDS or organ transplantation.

Symptoms of Herpes Zoster

Typically, a patient may have localized pain and itch even before herpes zoster appears. Herpes zoster affects skin along a dermatome on either side of the patient’s body. The patient should get medical help as soon as possible. It is less common for herpes zoster lesion to surround the body. however, such sporadic and widely spread condition may occur in people with suppressed immune systems. Appropriate treatment must be given in time to avoid serious complications that may lead to a life-and-death situation. On that account, we cannot deny value and significance of folk wisdom. (There is a myth that a patient would die if herpes zoster appears around the body in the Chinese community.)

Discomfort on skin caused by herpes zoster normally recovers within 2-3 weeks, followed by neuralgia that may last from one week to few months. Herpes zoster can cause severe complications including stroke, hearing loss (in case of herpes zoster growing around ears), keratitis or even vision loss (in case of herpes zoster growing around eyes).

Treatments for Herpes Zoster

Antiviral is a typical treatment for herpes zoster, but best period of an antiviral treatment is within 72 hours since rash onset. Antiviral can bring about a rapid drop in viral load, drying up rashes and reducing neuralgia triggered by the virus. Antiviral treatment is available in both vaccine administration and oral administration. An oral administered antiviral treatment usually continues for 7-10 days.

Herpes zoster may relapse at a typical rate of 1-6%. Due to its high incidence in people aged 50 or above, vaccination is a good way of prevention. But if you are preparing for any treatment that may weakens your immune systems, you should get vaccinated some time before your treatment as far as possible. There is a new recombinant vaccine requiring 2 doses launched in 2021. Efficacy rate of over 90% had been shown for this new vaccine for prevention of herpes zoster and its complication including postherpetic neuralgia.

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