Tuesday, July 26, 2011

Shingles: an update

Many years ago I heard Herpes Zoster - more commonly known as Shingles - described as "A belt of roses from hell", and it goes someway to describing the awful pain that shingles can cause. Herpes Zoster is the very same virus that causes chicken pox in young people. The natural history of the disease is that the child gets chicken pox, recovers and develops an immunity to the virus. The virus, meantime, lurks in for decades in the sensory cells of the spinal cord, unable to leave because of the circulating immune cells that are primed to kill it should it try to leave. However, as we get older, our "cell mediated immunity" declines, and at some point it may dip low enough to allow the virus to leave the sensory cells that it has inhabited and travel down the nerve attached to those cells, causing the classic rash eruption in the area of skin supplied by that particular nerve.

So what do we know about Shingles?

  • It is an illness of older age: prevalence increases over the age of 60: the estimated lifetime risk of shingles is 20%-30%.
  • Contrary to popular belief you can get it more than once: in fact the recurrence rate is about 6%.
  • Shingles is preventable. There is a vaccination for Herpes Zoster that not only reduces the risks of developing shingles, but will also reduce the impact of Post Herpetic Neuralgia - the terrible pain that can linger for many months after the rash has abated. 
  • The risk for clinically significant pain persisting for longer than 90 days is 14% in people with Zoster, aged 60 years and older.
  • Prevention is far more efficient and effective than trying to relieve Shingles. The powerful medications used in the attempt to alleviate the pain and distress of Shingles also can have powerful and unwanted side-effects too.
  • Vaccination is recommended for all non immunocompromized people over the age of 60, subject to appropriate advice from their treating physician.
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2 comments:

ClaireyH said...

This is interesting. I went looking for info about shingles when my child was diagnosed with them at 19months.

The doctor said it was the first case of pediatric shingles he had ever seen in thirty years. He expected it was because she had only recently had her chicken pox immunization and was then exposed to an uncle who wasnt sure what his annoying rash was(but never went to a doctor til we asked him to for a shingles diagnosis).

The rash lasted for weeks, but my concern was about it coming back if she was I'll again or what the life long concerns would be. I was never able to reallyfind any information about it, would love a post on the issue if you could.

Dr Duncan Jefferson said...

Thanks Clairey: I just love those curly questions!
Most of the research on recurrent Shingles has naturally been done on the elderly; and it seems to be a case of declining "cell mediated immunity" that increases the risk of recurrence. With immunization, or with infection from "wild" viral infection, the body will program it's immune cells to recognize the virus for decades to come. If you wanted to know the level of immunity that your daughter has to Herpes Zoster, then a blood test could easily give you the answer. Otherwise, you could simply wait until she is 40 or even 50 and then either have a blood test, or vaccinate against Zoster, or follow the current health advice that will be available then