Dear Doctor: A 94-year-old who suffered from shingles has pain and itching more than a year later

DEAR DR. ROACH: In March 2023, my 94-year-old mother had an episode of shingles on the right side of her neck, head, ear, and (to a lesser extent) right cheek. The active blisters lasted about three weeks. Since then, she has experienced persistent neuropathy that involves itching, a feeling of despair, and some pain. She has been prescribed gabapentin and takes two pills a day of 300 mg each. However, they don’t seem to help much. Her acupuncturist has indicated that gabapentin may not be the solution for her.

Her other medications include duloxetine. She has Alzheimer’s disease, diabetes, a history of falls and hypothyroidism. She has had three mini-strokes and was diagnosed with congestive heart failure. Is there anything else that can help alleviate her condition? Will the neuropathy ever go away? –KB

ANSWER: Unfortunately, your mother developed a complication of shingles called postherpetic neuralgia (PHN). The pain ranges from annoying to excruciating, and the itching can sometimes be worse than the pain. Both the pain and itching can lead to despair. Combined with Alzheimer’s disease, it must be heartbreaking to see her in so much discomfort.

The natural history of PHN is variable, but as a general rule, the older a person is when they develop shingles, the more likely they are to develop PHN. No matter how long it takes. Women are more likely to develop PHN, and I have read estimates that anywhere from 13% to 30% of people over the age of 80 with shingles will develop PHN.

Now that she has had complaints for over a year, she has about a 50% chance of recovery in the coming year. I don’t know of any treatment that will increase the chances of her recovery. However, both the gabapentin she takes and duloxetine (an antidepressant often used to relieve pain) may have benefits in relieving symptoms.

I often see patients like your mother treated with moderate doses of gabapentin. She takes 600 mg daily, but in the study where gabapentin was approved by the Food and Drug Administration for PHN, researchers had a target dose of 3,600 mg per day! This dose can be very sedating, and it takes a long time to slowly increase the dose before most people can tolerate it.

Some people (especially the elderly) simply cannot tolerate such a high dose. However, it’s worth a try. Even 300 mg three times a day will likely be significantly more effective than what she is currently taking. If she can tolerate it, her doctor can slowly increase the dose further. I always increase the night dose before the other doses because it makes people sleepy at a time when it is good.

Finally, it’s too late for your mother, but older people who have not had the newer two-dose shingles vaccine (Shingrix) should get it even if they have had the old one-dose vaccine (Zostavax) or in have had shingles in the past. The downsides of the vaccine (i.e. a sore arm, or a day or so of feeling under the weather) are, in my opinion, absolutely worth the benefit of a greater than 90% reduction in the risk of PHN.