Q: I had toxic shock four years ago when I was 14. I was very ill and hospitalized for a week. I've been told by several doctors not to use tampons ever again. I'm very active and do not appreciate this inconvenience. What new information is there on this disease? Also, what are my chances of getting toxic shock again if I do use tampons?

A: Toxic shock seems to be one of those medical mysteries that suddenly appear and then strangely begin to fade away.

First discovered in 1978, toxic shock mainly strikes menstruating women under 30, especially those who wear tampons. The illness is caused by toxins released into the body by Staphylococcus aureus, a germ normally found on the skin. It's still not clear what triggers this bacterium to turn harmful and produce these sometimes deadly toxins.

Toxic shock is rare -- fewer than 3,000 people have developed it since 1978. About one in 40 victims die from the illness. At first, nearly 30 percent of afflicted women got the disease a second time. But lately, and for unknown reasons, fewer than 3 percent of victims get it again.

Women who have never had toxic shock can reduce their already small risk of getting it by not wearing tampons or using them intermittently, for instance during only part of the day or night, or for only part of the menstrual period. Also, low absorbency tampons are safer than high absorbency ones.

It's difficult to give you a good answer about your risk of getting toxic shock again if you wear tampons, because the rate of recurrence is decreasing. But based on previous studies, I'd estimate your chances are between 3 and 25 percent.

Because you can get toxic shock again, you should be familiar with its symptoms:

Sudden high fever.

A sunburn-like rash at first, which leads to peeling of the skin in about 10 days.

Vomiting or diarrhea.

Drop in blood pressure (shock), which causes dizziness or fainting.

Severe muscle aches.

Sore throat.

Red eyes.

Headache.

If you ever think you have toxic shock, you should remove your tampon if you're wearing one, and get immediate medical attention.

Q: About a year ago my wife and I bought a new pick-up truck. We started noticing that on long rides her back would begin to itch, and she also developed a rash across her shoulders. Our doctor thought she might be reacting to something in the fabric protection treatment that we purchased from the dealer, and we agree. As long as she uses a towel between her and the seat, she has no problem. We'd like to know if other people have had this problem and how we can find out more about what's in the fabric protection spray so that she can avoid the offending agent.

A: It certainly sounds like your wife has a contact dermatitis, a skin reaction to something in the fabric protector.

The Consumer Product Safety Commission has received several reports about reactions like these to fabric protection sprays. This type of skin reaction seems to be even more common with a related product, laundry fabric softeners. If you're having this kind of problem, either avoid the product altogether, or avoid coming into direct contact with it, such as you've done by putting a barrier between you and it.

Here are a few suggestions for finding out about the components of various commercial products and whether there have been any harmful health effects reported:

Call or write the manufacturer. Many companies have consumer affairs departments to answer such requests.

Write the Consumer Product Safety Commission, Washington, D.C., 20207.

Ask your doctor to see if the ingredients of the product are listed in any of the standard toxicology textbooks used by poison control centers or in textbooks on contact dermatitis.

Q: Nine years ago I began losing weight drastically. I was hungry all the time, my hands and feet trembled and my eyes bulged out. The doctors diagnosed hyperthyroidism and I was treated with radioactive iodine. My symptoms disappeared soon after I started treatment. Recently my skin became very dry, something that's never bothered me before. Could this be the hyperthyroidism coming back?

A: I'd be more concerned that you were developing hypothyroidism (underactive thyroid gland) than hyperthyroidism (overactive thyroid gland).

It sounds like you had a common type of hyperthyroidism known as Graves' disease, named after an Irish physician. There are three main treatments for this condition -- medications, surgery and radioactive iodine.

Propylthiouracil (PTU) and Tapazole are two similar medicines doctors use to treat hyperthyroidism. One of their major drawbacks is that even after taking either of them for one to two years, there's still a chance that the hyperthyroidism will come back once you stop taking it.

Both surgery and radioactive iodine are more reliably effective, but both suffer an important side effect, the chance of becoming hypothyroid. This overshoot in treatment, turning an overactive gland to an underactive one, may happen soon after therapy or many years later.

Hypothyroidism more often follows radioactive iodine treatment than surgery, but this complication should be kept in mind for anyone having these procedures. I think it's important that you have thyroid blood tests done about once a year for the rest of your life to make sure you're not becoming hypothyroid. If you do develop this condition, it's simple to treat by taking a thyroid pill once a day.

Symptoms of hypothyroidism can be subtle and develop very gradually. Because dry skin is an early sign, I'd recommend getting your thyroid checked.