Causes of Shingles

Shingles are caused by the zoster virus that also causes varicella. After varicella sores heal, the virus lies dormant in nerves and may later become shingles. In other words, once you have had varicella, you are at risk of developing zoster. 

As you age your immune system weakens, making it easier for zoster to break through your body’s defences. Therefore, the risk of zoster increases substantially as you age. Besides this, people with high blood pressure, diabetes, gout and rheumatoid arthritis have weakened immune systems and their risk for zoster is higher. 

The first varicella vaccine was launched 20 years ago. Therefore, most people aged 50 or above have had varicella in the past. In Hong Kong, over 95% of people have had varicella and they are at a higher risk and are more likely to develop shingles. The risk is about one-third. 

Symptoms of Shingles

At the onset of shingles the patient may develop symptoms of tiredness, headache, an upset stomach or a fever that is similar to that of flu. They typically start to feel pain 24 to 48 hours from the initial onset. A rash or blisters appear on the skin as the virus spreads down one or more nerves. The shingle rashes are commonly found at the back and waist.

Shingles causes severe pain. Patients sometimes feel pain even though they do not touch the rash. The condition of shingles can range from mild to severe and it mainly depends on patients’ immunity and distribution of nerves as well as the virus’ activity. About 1/4 patients will experience severe complications, for example, the rashes extended to the eyes and ears and may lead to chronic ocular disease and visual loss.

Patients suffering from shingles should cover their rashes and avoid contact with the blister fluid. The zoster virus is communicable so people who have never had chickenpox may be infected from virus. Those people who have not had chickenpox before should be very careful when looking after patients with shingles. People who have had chickenpox will not be infected.

Treatment of Shingles

The best way is to have anti-virus medication for around 5-10 days within 72 hours from the onset. The medicine can control the growth of rashes and blisters and reduce the possibility of suffering from postherpetic neuralgia. Patients may take antidepressants or antiepileptic drugs for nerve pain but these may cause side effects.

Prevention of Shingles​

- Enhance your immune system

Pay attention to diet, do sufficient exercises and maintain good ventilation in inside spaces.

- Vaccination


1. Zoster Vaccine

SHINGRIX Herpes Zoster/Shingles (Recombinant, adjuvanted) Vaccine (age ≥50)

Shingrix is the shingles vaccine demonstrating over 90% efficacy in clinical trials. It provides strong protection against shingles and neuralgia, the most common complications of shingles.

Intramuscular Injection. A total of 2 doses are required to complete the vaccination

Schedule:2 doses separated by 2-6 months


2. Varicella Vaccine

Both shingles and varicella are caused by varicella zoster virus. If children receive the varicella vaccine, they will not be infected with shingles. Both doses of varicella vaccine should be administered at the age of 1 year and before primary 1.

Please note that all medical health articles featured on our website have been reviewed by Quality Healthcare doctors. The articles are for general information only and are not medical opinions nor should the contents be used to replace the need for personal consultation with a qualified health professional on the reader’s medical condition.