Dandruff is the mildest form of a condition called seborrheic dermatitis. At its worst, this condition leads to patches of red skin covered in tiny, greasy scales. Composite: The Guardian/Getty Images View image in fullscreen Dandruff is the mildest form of a condition called seborrheic dermatitis. At its worst, this condition leads to patches of red skin covered in tiny, greasy scales. Composite: The Guardian/Getty Images Call the doctor Well actually Not glamorous, but common: how to manage dandruff at home and when to get help Experts don’t know exactly what causes dandruff, but if you’re seeing light flakes on your scalp, over-the-counter products can help
Prefer the Guardian on Google Y ou spy a scatter of white flakes on your collar. Or you’ve got an itch that won’t quit, no matter how much you wash your hair. Dandruff isn’t glamorous, but it’s common: about half the world’s population has it.
An itchy, flaking scalp is rarely dangerous, but it can be annoying. Here’s what you need to know about what might be causing your flakes, what you can do about it, and when it’s time to get help.
Dandruff is the mildest form of a condition called seborrheic dermatitis, a type of skin inflammation that usually affects the head, face or trunk. At its worst, this condition leads to patches of red skin covered in tiny, greasy scales. However, most people with dandruff have just minor scaliness and no redness, affecting only the scalp.
Experts still don’t know exactly what causes dandruff, and it’s likely there are various contributing factors. A yeast called Malassezia is a leading suspect, says James Pathoulas, an assistant professor of dermatology at the University of Minnesota medical school who specializes in hair and scalp disorders. Malassezia usually lives harmlessly on the scalp, but overgrowth has been linked with scalp inflammation.
It’s better to think about seborrheic dermatitis as a system in dysfunction rather than one organism causing trouble, according to Natasha Mesinkovska, an associate professor of dermatology at the University of California, Irvine. Scalp health comes down to a “trifecta” of factors, she says: the scalp’s microorganisms, its ability to keep those organisms out of deeper skin layers, and the skin’s immune response to them.
It’s not clear why some people get dandruff and others don’t. Genetics may play a role – at least 11 gene variants have been linked to the condition – as can hot, humid weather or a supercharged workout routine.
Hormones that drive oil production can also ramp symptoms up or down, beginning around puberty and changing during pregnancy or menopause.
If you’re seeing occasional light scale on your scalp with no significant redness or itch, over-the-counter dandruff shampoo can help. Zinc pyrithione, selenium sulfide and ketoconazole are the three most common active ingredients. They’re all equally good at lowering Malassezia populations, tamping down inflammation, and stopping the flakes.
Pathoulas recommends massaging the shampoo into your scalp, not just your hair, and leaving it on for a few minutes before rinsing. Use it three times a week; either your regular conditioner or a dandruff-specific product is fine. If you want to wash your hair on in-between days, your regular shampoo and conditioner are fine.
Ketoconazole and selenium sulfide can dry out hair and cause breakage, especially for dry, highly textured or coily hair, Pathoulas says. If that occurs, or you already rely o…