Preventing Postherpetic Itch in Patient with Shingles

Case study:

A woman with shingles developed postherpetic itch and gave herself brain damage by scratching through the front of her skull. How could this development have been prevented?

Answer:

Anne Louise Oaklander, MD, PhD, of the department of neurology at Massachusetts General Hospital and Harvard Medical School, diagnosed postherpetic itch (PHI) as the reason the woman developed incessant itching above one eye and scratched through her skull and into her brain to cause permanent brain damage. The shingles had also caused a loss of periphery sensory neurons, which eliminated the pain sensation that usually prevents such aggressive scratching. Osteomyelitis had softened the patient’s skull, but shingles was the root cause of the itching and scratching. Dr. Oaklander said her now famous patient is an extreme example of the underrated dangers of shingles and a stark reminder of why a newly approved shingles vaccine is so important.

The U.S. Food and Drug Administration recently approved Shingrix, an extremely promising vaccine from GlaxoSmithKline. In a phase III clinical trial involving more than 38,000 older individuals, the vaccine was 90% effective in preventing shingles and demonstrated a sustained efficacy of more than 4 years. It also helped prevent postherpetic neuralgia, the most common complication associated with shingles.

“The vaccine has a staggering and unprecedented success rate — over 90% efficacy is incredible,” said Dr. Oaklander. “It is particularly effective in people over the age of 70, who are the ones at the highest risk for developing shingles and its complications, plus the hardest to vaccinate. That’s a home run by anyone’s standards.”

The most commonly reported side effects of the new vaccine are side effects are pain, redness, and swelling at the injection site, muscle pain, tiredness, headache, shivering, fever, and upset stomach. Those are classic reactions of vaccination, and a vast majority of people won’t experience them, pointed out Dr. Oaklander.

Shingles is caused by reactivation of varicella-zoster virus, which has been estimated to be latent in 90% of adults. The viral infection ultimately develops in one-third of Americans and the risk for shingles increases after the age of 50 due to a natural age-related decline in immune system function. Dr. Oaklander said the other currently available vaccine has been reasonably effective for individuals older than 60 years, but rates of immunization were lacking significantly because the elderly population has underestimated the seriousness of the condition.

“Shingles is actually a neurological disease—after chickenpox the virus becomes dormant in the peripheral nervous system, where it lurks as an internal threat,” commented Dr. Oaklander. “We all need to take it more seriously.”

What can providers and pharmacists do to educate elderly patients about the importance of vaccination? “Emphasize that shingles can cause stroke, brain damage, blindness, hearing loss, and lifelong chronic pain and itch,” said Dr. Oaklander. “It’s absolutely critical that people get immunized. How often are we presented with the chance to prevent a devastating neurologic disease?” 

—Dan Cook