It's not a life-threatening medical problem, although it can certainly maim your social life.
And while it's been around as long as hair, dandruff still perplexes doctors, who debate its cause (or causes) and the best treatment.
They do know that dandruff can make life miserable--especially since it usually can't be cured, only controlled. Dandruff sufferers' scalps often itch and have dry, flaky white scales. When flaking and itching become severe, the scalp can become red and irritated.
Luckily, options for getting rid of the pesky problem have been expanding, so if one treatment doesn't do the job, chances are another probably will.
The Survey: About 50 million Americans have dandruff, according to a recent poll conducted by the manufacturer of an anti-dandruff cream. While equal numbers of men and women are affected, men worry a bit more about how others will react to seeing dandruff on them. Some of the respondents told the pollsters that they would rather endure heartburn, athlete's foot or headache.
The Great Debate: What causes dandruff is still up for discussion, but the favored theory holds that a yeast-like fungus, Pityrosporum ovale , is to blame. The fungus grows naturally on everyone's scalp, but those with dandruff produce excess amounts. The overproduction in turn causes a reaction and inflammation on the scalp. Then comes itching and the ubiquitous flakes.
Whether dandruff is a form of seborrheic dermatitis--a scaly red condition that can afflict the scalp, eyebrows, nose and other body parts--or a separate entity is also debated, says Dr. Paul Wolfish, chief of dermatology at Kaiser Permanente, Woodland Hills.
The Stats: Dandruff can strike at any age, but its likelihood is particularly high in the 20- to 40-year age bracket. "Dandruff decreases as you get older, but seborrheic dermatitis increases," Wolfish says. Emotional stress can make dandruff flare up, Wolfish adds. Cold weather can make it worse too.
The Solutions, At-Home Variety: When dandruff appears, physicians first recommend patients try over-the-counter dandruff shampoos, of which there are many.
Some contain pyrithione zinc (Head & Shoulders) or selenium sulfide (Selsun Blue). There are also coal tar shampoos (such as Tegrin). "These can change the color of your hair, especially if it is white or bleached blond," Wolfish says. Other formulas have salicylic acid (T/Sal).
Whatever dandruff shampoo is selected, it's a good idea to shampoo frequently, says Henri Mastey, a chemist and chief executive officer of Mastey de Paris in Valencia, a hair and skin products manufacturer. "The more you clean the scalp the better," he says.
Using a dandruff shampoo two or three times a week and regular shampoo in between if necessary is advised by Dr. Richard S. Berger, a clinical professor of dermatology at the Robert Wood Johnson Medical School in New Brunswick, NJ. He urges proper use.
"When patients use over-the-counter shampoos, they (often) don't use them properly," Berger says. Most common mistake: They don't leave the preparations on the scalp for several minutes as instructed. Five to 10 minutes is good.
Another option, which Wolfish sometimes recommends, is to use a non-prescription dandruff shampoo and then apply an over-the-counter hydrocortisone cream and leave it in to combat inflammation.
Calling In the Cavalry: If there's no improvement after three or four weeks of home treatment, it's wise to consult a dermatologist or other physician. A physician might prescribe a dandruff remedy, such as Selsun (selenium sulfide) in 2.5% strength and Nizoral (ketoconazole) cream. Nizoral, manufactured by Janssen Pharmaceutica, might soon be available over-the-counter. Johnson & Johnson, the parent company, has asked the U.S. Food and Drug Administration for approval to market it on a non-prescription basis, says Robert Kniffin, a J & J spokesman.
Another option, Wolfish says, is to use an over-the-counter dandruff shampoo and then apply a prescription-strength steroid lotion.
The Study: In a comparison study, ketoconazole shampoo and selenium sulfide shampoo were both found effective in fighting dandruff in 246 patients, says Dr. William Danby, chair of the division of dermatology at Queen's University in Kingston, Ontario. His study, backed by Janssen Pharmaceutica Inc., was published recently in the Journal of the American Academy of Dermatology. While both shampoos worked, he found that the ketoconazole shampoo was better tolerated and less likely to involve side effects such as lightening of hair color or burning of the scalp.