DEAR DR. DONOHUE: When I was in my early 20s, I began to get a couple of white skin patches. The number of these patches has increased, and I have some on my face. I am a 34-year-old black woman who recently had a baby. Is there any treatment for this? Did I pass it on to my baby? – J.J.

ANSWER: You have vitiligo. It occurs in all races. In close to 50 percent of vitiligo patients, the onset begins before age 20.

Melanocytes are skin cells containing the pigment melanin. With vitiligo, melanocytes disappear. Involved skin turns white. The mechanism by which this happens hasn’t been completely established, but the belief is that it’s the result of an immune attack on the pigment-containing cells.

Vitiligo might consist of only a few patches, or it might be more widely distributed. In a few, the entire skin is depigmented. The face, upper chest, backs of the hands, groin, elbows, knees and the skin around the eyes and lips are frequent sites of involvement.

With some patients, there is an associated illness such as diabetes, pernicious anemia or an overactive or underactive thyroid gland.

Although in 20 percent to 30 percent of vitiligo patients, a family history discloses other members with it, that doesn’t mean that a child of an affected person will also be affected.

Cortisone creams or ointments applied to depigmented patches can sometimes restore melanocytes. Some have found success with Aldara cream. Ultraviolet light therapy, often in combination with a psoralen drug, is another possible treatment. Some choose to cover the patches with cosmetics. Dermablend and Covermark are two popular brands.

The white patches are very sensitive to sunlight, so you should protect them with sunblock whenever you go outside.

DEAR DR. DONOHUE: For a number of years I have tolerated rheumatoid arthritis. It’s getting worse, and my doctor suggests that I go on methotrexate. I have researched this drug on the Internet, and it has many scary side effects – so scary that I am reluctant to take it. What’s your opinion of this drug? – C.T.

ANSWER: Methotrexate, one of whose brand names is Rheumatrex, is a drug used for many illnesses. In addition to rheumatoid arthritis, it has found a place in the treatment of psoriasis, Crohn’s disease and some cancers.

In rheumatoid arthritis, it has properties that most other treatments don’t. It can actually slow or even stop the progression of this potentially deforming and incapacitating joint disease. Few other medicines can do that.

The list of possible side effects would make a stoic shudder. It can damage bone marrow, the intestinal tract, lead to infections, hurt the kidneys, cause hair loss, and the list goes on.

I can honestly tell you that if I needed it, I wouldn’t hesitate to take it. Doctors carefully watch patients taking drugs like this one. At the first sign of possible toxicity, they stop the drug.

DEAR DR. DONOHUE: What is a coxsackie infection? I felt terrible for a week and had to take to my bed for a couple of days. I called my doctor, and she said it was probably a coxsackie infection, since they were going around. Is there any medicine for it? I didn’t get any. – F.R.

ANSWER: Coxsackie (kok-SACK-ee) viruses can be found just about anywhere in the world, and coxsackie infections are quite common. Usually they are minor infections with mild fever, headache and an out-of-sorts feeling. Sometimes they cause respiratory symptoms. In others, they disturb the digestive tract, and people become nauseated and vomit. In a few people, the infection is serious, for the virus can infect the brain and its coverings (encephalitis and meningitis), the lungs (pneumonia) and the heart muscle.

There is no medicine for the usual coxsackie infection.

These viruses were first discovered in Coxsackie, N.Y., and that’s where the name comes from.

DEAR DR. DONOHUE: An outbreak of lice hit my 8-year-old son’s school. He brought home a sheet of instructions about what to do for any infected child. He was infected. He catches everything. We followed the instructions, but he hasn’t been allowed back into school. They say he still has lice. What are we supposed to do? He’s not scratching like he was. – C.P.

ANSWER: About this time every year, mothers are horrified to learn their child has picked up lice, usually at school. Sometimes schools enforce unreasonable regulations for permitting children to return to classes, and sometimes they have inspectors far too zealous in their search for undercover lice. Maybe your son is a victim of lice phobia.

Head lice spread via close contact of the uninfected with the infected and through sharing hats and combs.

A female louse is a true reproductive machine. She lays more than 100 eggs, called nits, which stick to hairs. In eight to 10 days, the nits hatch and rapidly mature into adults. When the adult louse pierces the skin to obtain a blood meal, she simultaneously salivates. The saliva induces an intolerable itch. Adult lice can live for 30 days on the scalp. On inanimate objects – clothes, bedding, toys – they live only about three days.

There are four commonly used medicines – Nix, Elimite, Rid and Ovid – that usually eliminate the pests if directions for application are followed to the letter. Most of these products require a second application seven to 10 days after the first application. The second course takes care of hatching nits.

In Britain, it’s a common practice not to use medicines. The infected person’s hair is wetted, and a fine-toothed comb (a louse comb, if you will) is run through the wet hair to dislodge lice and nits. This procedure is repeated four days in a row. The comb is washed in hot, soapy water after each use. Adopting this treatment might get your son back to his school desk.

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