Your anti-dandruff strategy: fight a flaky, itchy scalp with these prevention and treatment tips

Shape, March, 2008 by Carly Cardellino

Suffer from scalp flakiness (aka dandruff)? You're not alone. This embarrassing, persistent condition affects 50 percent of people in the U.S. every year. To explain why it occurs and how to get rid of it, we turned to Zoe Draelos, M.D., a dermatologist in High Point, North Carolina.

The basic facts

Dandruff is caused by a microscopic yeast called Malassezia that lives on everyone's scalp and feeds off the oil, or sebum, that keeps skin hydrated. Normally, as dead skin cells are shed, this yeast gets washed off in the shower or brushed away. Under certain conditions, however, it grows out of control, irritating your scalp and making it red and itchy. In response, your skin cells begin to reproduce at an accelerated rate; as they build up, they turn into flakes.

What to look for

* Genetics If your mom or dad has dandruff, there's a strong chance you will too.

* An oily scalp This causes the yeast to multiply.

* High indoor temperatures When you're in a warm environment, your scalp secretes more oil.

* Stress, illness, or a hormonal imbalance All three of these factors may make you less resistant to fighting off the accumulation of flake-producing yeast.

Simple solutions

* Use a medicated shampoo These cleansers typically contain the anti-yeast ingredient zinc pyrithione. Find it in Head & Shoulders Dry Scalp Care Shampoo and Conditioner ($5 each; at drugstores); both products deposit tiny yeast-destroying particles of the active ingredient on the scalp, where they remain until you're able to shampoo again.

* Use stylers sparingly Gels, mousses, and pomades can trap sebum and exacerbate flaking.

* Minimize scalp oil If your hair still looks greasy despite daily cleansing, spritz on Biolage Scalptherapie Cooling Mint Oil Control Treatment ($16; biolage.com for salons), a spray with sebum-absorbing glycerin.

EXPERT STRATEGY "It's a myth that dandruff is caused by a dry scalp," says Zoe Draelos, M.D. "It's the result of a buildup of yeast, and it needs to be treated with a medicated shampoo at least twice a week."

* The bottom line The scalp sheds skin cells daily, so a bit of flaking is inevitable. But if you notice lots of flakes on your clothing or find yourself constantly itching, take action. All that scratching will aggravate your condition and could cause split ends.

RELATED ARTICLE: THE SCALP

1. malassezia

2. sebum

3. skin cells

4. flakes