DEAR DR. DONOHUE: Two years ago I had shingles, and I now suffer the aftereffects of it. The sores went away in a month, but the stinging, burning, throbbing pain is still with me. I cannot wear clothing over the affected shoulder. No medicines have eased the pain so far. Is there any help? — M.L.

ANSWER: You now are dealing with postherpetic neuralgia, pain that lingers long after the shingles rash has gone. The virus that causes shingles is the same virus that causes chickenpox. Almost every adult on this continent harbors that virus, now called herpes zoster. It lives on in nerve cells. From time to time, at older ages, it wakens from its hibernation, travels down the nerve to the skin and causes an outbreak of blisters on a red base. The outbreak goes away in about three weeks. Pain can linger for a long time — months, to years. In traveling down the nerve, the virus damaged it.

I can list some of the postherpetic neuralgia medicines. Two are antidepressants — nortriptyline and amitriptyline — given not for depression but for pain relief. Cymbalta (duloxetine) is another antidepressant that can lessen postherpetic pain. Lyrica (pregabalin) is an anti-seizure medicine that’s approved for this problem. Neurontin (gabapentin) is another seizure medicine used for control of the lingering pain of shingles. Capsaicin lotion, cream or gel (Zostrix, Capsin, R-Gel) is applied directly to the involved skin. A higher concentration of capsaicin comes as a patch that’s applied in the doctor’s office, left on for an hour and then removed. Treatment can be repeated in three months. It’s called Qutenza. Another skin patch is the Lidoderm patch. The latest medicine is Gralise, an extended-release form of gabapentin — Neurontin. It requires fewer doses.

The entire shingles story is covered in the booklet on that topic. Readers can obtain a copy by writing: Dr. Donohue — No. 1201, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: You had a column in the paper about the shaking illness that affected actress Katharine Hepburn. You said it wasn’t nerves. I meant to keep the column, but the paper got thrown out. Would you repeat the information? — C.R.

ANSWER: The illness is essential tremor, also called familial tremor because it often turns up in many members of a family. It’s isn’t “nerves” in the popular sense of that word implying nervousness. It has to do with a dysfunction of the motor-control part of the brain. “Motor” here indicates muscle action.

Essential tremor makes it hard to bring a spoonful of soup to the mouth, to write or to do anything requiring precise use of the hands. The tremor can affect the head, as it did in Ms. Hepburn’s case. It might even give the voice a trembling quality.

Propranolol or primidone can suppress the tremor for most people, if treatment is necessary. Some people are so mildly affected that they don’t want treatment. Others are so profoundly affected that medicines can’t control the shakiness. In such cases, brain stimulation often can restore normal movement.

DEAR DR. DONOHUE: As someone preparing for a liver biopsy, please discuss the procedure, recovery and possible side effects. — R.J.

ANSWER: Doctors perform a liver biopsy with a needle attached to a suction device that can capture a thin piece of the organ for microscopic examination. The needle is inserted through the skin over the liver. First the doctor cleans the skin with an antiseptic and often numbs it. The procedure takes less than a minute. You return home shortly thereafter.

Side effects are rare. Bleeding is possible. So is infection. Neither happens frequently.

You don’t have to prepare yourself in any special way.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.