Childhood photographs of Dr H show it clearly. A mini-crater/depression right in the centre of my forehead. It’s legacy of a bad bout of chickenpox when I was around five. In hindsight, I could have chosen other more discretely located pox blisters to repeatedly pick at.
As I write I can still feel a slight depression in my skin some 50 years later. It’s time to think about another possible chickenpox complication. Shingles is caused by reactivation of the varicella zoster virus, the same virus that causes chickenpox. A person’s risk for shingles increases sharply after 50 years of age. Nearly all adults over 50 have the shingles virus dormant in their nervous system, from the time they had chickenpox.
It sits there, waiting to reactivate with advancing age.
Zoster comes from Greek, meaning "belt" or "girdle", after the characteristic belt-like distribution of the rash. The common name for the disease, shingles, derives from the Latin cingulus, a variant of Latin cingulum meaning "girdle". In Arabic its name means "belt of fire" and in Norwegian its name is helvetesild, literally "hell's fire".
Neither is an exaggeration.
The pain of shingles has been equated with that of childbirth and the pain experienced when passing a kidney stone. I have seen patients in extreme pain with the infection. They typically describe a burning or stabbing pain in the area affected by the rash. And I have seen some older people suffer for years from post-herpetic neuralgia, where the acute pain never settles, leaving them with a chronic, disabling condition.
About one in three of us will suffer a bout of shingles in our lifetime. The risk of shingles increases as you get older, and about half of the cases occur in men and women aged 50 and older. Shingles can affect anyone, but those at particular risk have a weakened immune system, are over 50, are under stress or have experienced recent trauma. While it’s possible to get shingles more than once, this is rare.
Like many viral infections, shingles often starts as a headache, nausea and a high temperature. Some people experience tingling, itching or stabbing pain before the rash appears. The characteristic rash develops on one side of the body and can last for two to four weeks. Initially, it has the appearance of fluid-filled vesicles before becoming a red crusty rash.
Post-herpetic neuralgia is the most common complication of shingles, occurring in up to 30 per cent of all cases. This occurs when the pain persists after the rash has disappeared and can last for several years. It can be quite difficult to treat as it tends not to respond to regular painkilling drugs.
Prevention, therefore, is key.
And there was some welcome news in late January, when the European Medicines Agency approved a new shingles vaccine, Shingrix, for people over 50. Compared with an older vaccine, Zostavox, the new one prevents shingles rash in over 90 per cent of cases and is also more effective in older people.
Similarly, if you look at the protective efficacy against post-herpetic neuralgia, it’s in the high 80 to mid 90 per cent range, and the duration of protection is much longer. The addition of a new purified protein is credited with this remarkable level of effectiveness.
Final approval for the new vaccine is expected in April. With no major side effects noted following approval in Canada and the US last year, I will certainly consider having the two-dose vaccine once the first tranche of post-marketing surveillance confirms Shingrix's clean bill of health.
Post-herpetic neuralgia has the potential to seriously affect the quality of life of older people.
With the approval of the new shingles vaccine, us over-50s can choose to stack the odds of this viral lottery in our favour.
