Chickenpox is a common childhood illness and after one has had this infection, the virus remains in the body, lying dormant in the root of the sensory nerves that supply the skin. From there, the virus can be re-activated and travel back down the nerve to the skin, causing the rash and, in some cases, the severe pain that is characteristic of shingles.
"Anyone who has had chickenpox is at risk of getting shingles," says Dr Allison Glass, a specialist virologist at Lancet laboratories. "However, because in children, exposure to the chickenpox virus can have very mild symptoms, they might not even remember having had chickenpox. The immune system can suppress and keep the virus under control for many years, but, with time and as one gets older, there is a decline in natural immunity and the virus can flair up again, presenting as shingles."
The first symptoms of shingles usually include tiredness and headache, followed by abnormal sensations such as itching or tingling in one area of the skin. A few days later, a chickenpox-like rash develops, starting with red patches that go on to form clusters of small blisters.
The shingles rash is characteristic, limited to the area of the skin that is supplied by the specific nerve on either the right or left side of the body, front and back, but not crossing the midline.
The skin usually returns to normal over a period of two to four weeks, but it can leave scarring and permanent changes in pigmentation. Pain levels can vary in intensity from mild to severe, where even a light touch or mere breeze crossing the skin can be unbearable.
There is no way to predict who will develop shingles or what may trigger the reactivation of the virus. However, a reduction in immunity occurs naturally with advancing age or may be caused by illness or some types of medical treatments. Consequently, the risk of shingles increases as one gets older and likelihood of persistent pain increases dramatically after the age of 50.
"About one in three people who develop shingles may continue to suffer from chronic pain six months after the initial illness," says Dr Jody Pearl, a neurologist in private practice in Johannesburg. "We call this prolonged pain post-herpetic neuralgia or PHN. This chronic pain is debilitating and can lead to other consequences such as sleeping problems, depression and social withdrawal.
"Depending on the nerves involved and the severity of the illness, other complications can also occur. The worst of these include paralysis, stroke or blindness."
Dr Milton Raff is the director of the Christian Barnard Memorial Hospital Pain Clinic in Cape Town and specialises in treating chronic pain. "The problem with shingles-related pain, is that it is so difficult to treat. Because it results from abnormally functioning nerves, regular pain medications are not effective. We only have a few specialised medications we can try. If these prove to be ineffective, then the pain can be incapacitating. In a small proportion of patients, the pain never goes away. Not only does the patient suffer severe pain, they can often not perform routine everyday tasks."
Commonly used medicines to treat shingles, including chronic pain of shingles, include antivirals and medicines for neuropathic pain. The cost of these medicines in the private sector can reach approximately R800 per month.
Recently a shingles-specific vaccine has been developed. "This is a major breakthrough," says Dr Raff. Studies show that the vaccine can prevent the development of shingles in up to 7 out of 10 people who would have got it had they not been vaccinated, and it significantly reduces the occurrence or severity of pain among vaccinated individuals who do get shingles.
In South Africa, children can be vaccinated against chickenpox as part of their routine vaccination schedule. "Now that the new vaccine is available, it is just as important for adults over 50 to be vaccinated against shingles. I would recommend that everyone over the age of 50 should speak to their doctor about getting vaccinated," concludes Raff.
