Dr. Roach: When shingles lingers, the pain is called postherpetic neuralgia

Keith Roach
To Your Health

Dear Dr. Roach: My spouse, now 61, had shingles two years ago. Though the rash cleared up quickly, the nerve pain has never subsided. Is the virus still at work, or does she have permanent nerve damage? Because her doctor has always kept her vaccines up to date, we are not sure how she missed getting a shingles vaccine, unless she was below the recommended age threshold at that time.

— B.L.

Dear B.L.: Shingles is the reappearance of the chickenpox virus after it has lain dormant for years (usually decades) in the body. It could be since the time of the original chickenpox infection or, less likely, since vaccination with the varicella vaccine.

Dr. Keith Roach

During the time of the rash, and often for a week or two afterward, the pain is due to inflammation and damage to the nerve, called acute neuritis. After four months, however, the diagnosis is now called postherpetic neuralgia, and it is a type of neuropathy, the general term for nerve damage.

The older a person is, the longer postherpetic neuralgia tends to last. About 20% of people will have pain for their lifetime, but your spouse is still more likely to have the pain go away than last forever. I am hopeful the nerves will recover and that the damage is not permanent.

Until her recovery, I hope she is getting some treatment to relieve the pain. Gabapentin and pregabalin are the most commonly used treatments. If a person can tolerate the full dose (it can take weeks to get people to tolerate the full dose of gabapentin, which is up to 1200 mg three times daily), it can be very effective, dramatically improving a person’s quality of life.

The newer shingles vaccine, a two-dose recombinant vaccine with the brand name Shingrix, became available in 2017 and is very effective. Your wife might have missed the new recommendation of getting it at age 50, as the old one-dose vaccine Zostavax (no longer available in the U.S.) was recommended to be given over age 60. Readers over the age of 50 who have not had the two-dose Shingrix should get vaccinated, even if they have had the old shingles vaccine, and even if they have had a history of shingles in the past.

Dear Dr. Roach: For the past three years, my creatinine levels have been pretty much normal. I am 75 years old, and my blood pressure is controlled with medication. However, last week, my creatinine level was elevated. On the eve of my lab test with dinner I took a couple of hard liquor drinks. Would this elevate my creatinine?

— J.M.

Dear J.M.: Alcohol can absolutely damage the kidneys. Since creatinine is a test of kidney function, the alcohol could have affected the results. In fact, a binge (defined as four or more drinks for women, five or more for men at any one time) can cause acute kidney injury. “A couple” of drinks might meet criteria for a binge, depending on how large the drinks are. One and a half ounces of 80-proof liquor is a standard drink, and some people pour much larger portions.

However, what’s more likely is that alcohol drinking often leads people to get volume-depleted. “Dehydrated” isn’t the correct term, since people lose salt as well as water, and I suspect this is the reason your creatinine is elevated. Still, there are many causes, and since your creatinine was higher than your usual, it’s worth rechecking. Be sure to drink plenty of fluid and avoid excess alcohol before your next blood draw.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.