Q: About a year ago my eyes became dry and itchy. My mouth and throat also became abnormally dry, particularly at night. Can you give me any information about possible causes, prognosis and possible treatment?

A: You may have something known as Sjogren's syndrome, named after the Swedish physician who first described it.

This condition leads to dryness of some normally moist tissues of the body, so you develop dry eyes, nose, mouth, throat and windpipe. This in turn causes symptoms such as you're having, including a dry, gritty sensation in the eyes, frequent nosebleeds, difficulty chewing foods, dental cavities, hoarseness and cough.

Sjogren's syndrome usually strikes middle-aged women, and is uncommon in men. The cause is unknown, but it has to do with the body's immune system going awry. One result is that white blood cells attack and disable the glands that make tears and saliva. The parotid glands -- the major saliva-producing glands in the cheeks -- may swell, resembling childhood mumps. In addition, about half the time people with this syndrome have another immune disorder such as rheumatoid arthritis. Less frequently, other problems occur, such as anemia, kidney disease and, rarely, lymphoma, a lymph gland cancer.

The disease itself is usually mild, but occasionally can be severe, especially if it's associated with another immune disorder. In most cases, symptoms are annoying rather than a serious threat to your health. For dry eyes, you can try artificial teardrops, such as Tearisol, or Lacrisert, a prescription product placed under the bottom eyelid. For troublesome mouth dryness, you can try saliva substitutes, such as Xero-Lube, available over the counter.

To confirm the diagnosis of Sjogren's syndrome, see your doctor. Not all cases of dry eyes and dry mouth are due to this disorder. For instance, many elderly people have decreased production of tears or saliva.

Q: In your answer about a stomach virus causing vomiting and diarrhea in adults Jan. 29 , you didn't say much about infants and children. As a mother of an infant and a toddler, I'd like to know more about treating these problems at these ages.

A: Treating intestinal viral infections that cause vomiting and diarrhea in small children is a little trickier than in adults. You have to be more on the lookout for signs of dehydration.

If your child only has diarrhea, it's easier to take care of. Basically, your main job is making sure he's drinking plenty of fluids and that more is going in than going out.

Sometimes you may need to hold off on milk products if your child has had a bad case of diarrhea. For a prolonged course of diarrhea in infants, your doctor may want you to use a soy formula. Inflammation in the intestines can lead to problems absorbing milk, which can cause further diarrhea. Occasionally other foods, like apple juice, have also been known to prolong episodes of diarrhea.

Treating vomiting is a little more difficult, because the fluids that you're trying to replace often come right back up. The trick here is to start with small amounts and increase them slowly.

Your doctor may want to modify the following schedule of feedings, but here's one way to do it. For children under 1 year, start with one-half ounce (one tablespoon) every 20 minutes. For children over 1, start with one ounce every 20 to 30 minutes. Gradually increase the amounts, by about one tablespoonful at a time, as long as your child is tolerating them. If he starts vomiting again, drop back to the beginning.

Fluids you can use are water, clear juices, flat ginger ale, popsicles and commercial preparations containing water, sugar and salt, such as Lytren, Pedialyte and Pedialyte RS (extra strength). Ask your doctor the best way to use these products. I don't advise making your own sugar and salt solution, especially for small infants, unless you're given specific instructions by your doctor.

Once your child is taking fluids okay, you can try adding solids, starting with foods like rice cereal, crackers, toast and bananas.

Even with a lot of vomiting, most infants and children do well with frequent intake of fluids. But you should also be aware of the signs of dehydration:

Listlessness, lethargy, lifelessness.

Absence of tears when crying.

Dry mouth.

Sunken eyes.

Irritability.

If your child develops these signs, get medical attention right away.

Q: Is there any risk of getting AIDS from acupuncture treatments?

A: No cases of AIDS have been known to occur from acupuncture treatments. Because AIDS is mainly passed by sexual contact and by sharing needles among intravenous drug abusers, there's a theoretical risk of getting the AIDS virus from contaminated acupuncture needles.

But even in cases in which health care workers have been stuck by needles used on patients with AIDS, the risk of getting the disease is extremely low. In fact, there is only one case on record that seems to show that transmission occurred in this way, in spite of the hundreds of health care workers who have been stuck with contaminated needles.

In any event, the AIDS virus is killed by standard sterilization techniques. It is sensitive enough that even a 1 to 100 dilution of regular household bleach will kill it. As long as your acupuncturist sterilizes his or her needles -- a standard practice that will prevent transmission of the hepatitis B virus as well -- you needn't worry about getting AIDS from acupuncture treatments.