Several years ago, Sara Taggart started noticing she was losing a lot of hair whenever she took a shower. As she combed it, more hairs would end up in the sink. Then one day she noticed a patch of bare skin on the back of her head - a bald spot.

Taggart, who manages a private estate in Baltimore County, was distraught. Her mother had lost a lot of her hair in her 60s and 70s, gradually becoming bald. But Taggart was only 53.

"I was afraid this was going to happen to me, too," she says. "My family started noticing I was losing my hair. Then my friends said, 'Oh my goodness, you're losing a lot of hair.' It was making me so uncomfortable and depressed, I started shopping for a wig. Then I said 'No! I've got to go for help.' "

After examining her thoroughly to rule out any medical reason for hair loss, dermatologist Robert Weiss prescribed spironolactone. A diuretic commonly used for high blood pressure, spironolactone also blocks androgens, male hormones that can accelerate hair loss.

Taggart's hair has grown back healthy and thick, but she remembers the scare.

Although most attention has focused on men who lose their hair, hair thinning and shedding is common in women and can be more devastating, dermatologists say.

For reasons ranging from chemotherapy to the hormones of pregnancy, millions of American women experience the shock of temporary hair loss. But some have genetic hair loss because of the same hormonal process that causes men to bald. The American Academy of Dermatology says there are no statistics available on exactly how many.

Genetically based hair thinning, known as androgenetic alopecia, can be tougher psychologically on women than on men, says dermatologist Margaret Weiss, an assistant professor of dermatology at Johns Hopkins Medical Institutions who operates a private practice in Baltimore County with her husband, Robert.

"Hair loss doesn't have to be as severe in a woman as it is in a man for her to feel [unattractive]," says Margaret Weiss. "A guy can have just enough hair to frame his face and look fine - but for a woman, the same amount of hair would not look fine.

"Psychologically, hair loss is very difficult for women because society is so much less accepting of their physical imperfections. There are no bald role models for women as there are for men. And even though it is very tough on men to have their hair thin, they've seen their fathers going through it."

Composed from a form of protein also found in fingernails and toenails, hair depends upon a diet that contains adequate protein. Each hair shaft is rooted in a minute tube of skin called a follicle, which operates on a fairly predictable schedule of growing and resting. Normally, a growing phase will last several years followed by a resting phase of several months. Then new hair begins to grow and the old hair falls out.

It is normal to lose 50 to 100 hairs a day. Blonds have the most hair - about 140,000 hairs - followed by brunettes - 105,000 - and redheads - 90,000. Hair grows about a half-inch each month; but as people age, the rate can slow.

The normal adult hairline is in the shape of an M, differing from the juvenile straight-across hairline. In men with genetic pattern baldness, the hairline can recede to resemble a W, but women with genetically thinning hair usually maintain their hairline while the hair thins on the top of their heads.

Androgenetic alopecia occurs when a person possesses an excess amount of an enzyme that converts the testosterone in their follicles into another male hormone, dehydrotestosterone, or DHT. DHT causes follicles on the scalp to shrink and grow hairs that are finer, shorter and less pigmented. Eventually the follicles stop hair production.

This condition can be inherited from either side of the family. Like men, women with androgenetic alopecia can begin losing their hair in their teens, 20s or 30s. Though they never become bald the way men do - they don't have as much testosterone to create DHT - some women will see a male pattern hair loss of an enlarging bare patch at the top of the head. Many more women will get diffuse hair loss all over the head.

Dermatologist Lynn Drake, president of the American Academy of Dermatology and chairwoman of the department of dermatology at University of Oklahoma Health Sciences Center, believes many women who are told they have genetic pattern baldness are mistakenly diagnosed.

"There are over 290 drugs - such as beta blockers or lithium - that have been associated with hair loss in women," she says. "If you stop or change the drug, the hair loss stops too."

Many other underlying causes, such as thyroid disease and a type of anemia that is not revealed by the usual blood test, can cause hair loss. Drake has also observed that some vegetarians who don't get enough protein and certain long-distance runners - those who also have problems ovulating due to low body fat - lose scalp hair.

She says genetic pattern hair loss should be the diagnosis of last resort. "Sometimes something serious can get overlooked. Women with systemic lupus, for instance, will show an androgenetic hair-loss pattern. There are all these other causes of hair loss: nutrition, endocrine, infections, systemic."

One type of dramatic hair loss is believed to be the result of an auto-immune condition. Alopecia areata, which affects about 4 million Americans, can cause patches of hair to come out for no apparent reason. Some patients lose all body hair, including eyelashes and brows and nose hairs. The loss is often permanent. There is no definitive treatment, but cortisone shots help some patients.

Treatments for genetic pattern hair loss range from applying medication topically to surgical transplantation. Last May, a drug study showed that Propecia, the pill that combats mild to moderate baldness in men, was not effective for hair loss in post-menopausal women.

Many dermatologists prescribe daily applications of Rogaine, a medication that seems to halt follicle shrinkage and encourage resting follicles to start producing again. The hair will come in over four to eight months and resemble peach fuzz at the beginning. Treatment must continue or the person may lose the hair he or she has regained.

Not all women get a regrowth. Studies suggest that Rogaine is more effective for men than for women, a finding that suggests again to Drake that many women are misdiagnosed with genetic pattern hair loss.

Any sudden hair loss, she says, should be taken seriously.

"Some physicians might say 'It's because you're getting older' or 'It's because of your hormones.' If a woman thinks she's losing hair, her physician had better listen to her because she is."

WHAT CAN THIN YOUR HAIR

Many women are confused by the signs of thinning hair, says Dr. Linda Lutz, assistant professor of dermatology at University of Maryland Medical Center.

"They often tell me their hair is coming out by the roots when it's actually breaking off," she says. "Sometimes they think their hair is shedding when it's actually thinning.

Patients don't always know what it is that is going on and may not know how long it's been going on."

It helps to know common causes of shedding:

* Pregnancy. The hormones of pregnancy suspend normal hair shedding, so women can lose larger amounts of hair than usual for several months after delivery. Problem usually corrects itself.

* High fevers, infections, severe flu and surgery requiring anesthesia. Usually this shedding doesn't begin for several months. Usually corrects itself.

* Overactive and underactive thyroids. Usually corrected with medication.

* Poor diets. Some people who go on crash diets or have abnormal eating habits develop protein malnutrition. Massive shedding can occur months later. This may be reversed.

* Medications. Chemotherapy, beta blockers, anti-depressants, gout medication, blood thinners, some antibiotics, high doses of vitamin A.

* Birth control pills. Those women who find their hair thinning while they take the pill may have a genetic tendency toward thinning hair. After stopping the pill, women may notice a delayed shedding period comparable to what some women experience post-partum.

NTC SAVING YOUR HAIR

To preserve your hair, the American Academy of Dermatology recommends:

* Be gentle with your hair when it's wet, the time it's the most apt to break off. Don't rub it too vigorously with a towel, or brush or comb it too roughly.

* Alternate hairstyles that pull the hair tightly - pony tails, corn rows, braids - with looser styles. Constant pulling can cause hair loss, especially from the sides of the scalp.

* Brushing your hair 100 times a day will damage it. Use wide-toothed combs and brushes with smooth tips.

* Perming, bleaching, coloring will not cause hair loss, but may cause hair to become brittle and break off if done incorrectly or too frequently.

Pub Date: 11/29/98