What to do about dandruff

January 20, 2020 / Duncan Fisher
Common-sense advice for a very common problem

For something so harmless, dandruff can sure be a nuisance. Dandruff is those white flakes that can embarrassingly appear in our hair, and fall like snow onto our clothes. It’s the itchy scalp, that worsens in dry winters, and flares sometimes when we’re stressed.

People used to think dandruff was evidence of dirty hair, and poor hygiene, but it’s generally not. It’s actually a condition with probable hormonal involvement (men get it more than women do), that associates markedly with age (it usually starts in young adulthood), and that may be related to a number of diseases, as various as Parkinson’s and HIV.

Its direct cause, as a rule, is ordinary dermatitis, of a kind that anyone can get, at pretty much any time. Luckily, it’s not, by itself, serious. And it’s very treatable.

What usually causes your dandruff

Dandruff, by definition, is just heavily flaking skin. Ordinary dryness is the usual reason. That’s why dandruff is so often a winter thing. Humidity drops in the cold months.

Another cause is an overgrowth of yeast on the scalp, encouraged by an overproduction of skin oil. This is spoken of as seborrheic dermatitis, and it’s the same thing as the ‘cradle cap’ that newborn babies get.

Other underlying conditions are scalp eczema and psoriasis.

How to treat your dandruff

You’ll hear a lot about home remedies for dandruff. Some of them, like various plant oils, may help flaky patches of dead skin loosen and clear. (Baby oil does seem to ease cradle cap a little.) Others, like baking soda or vinegar, might theoretically be of use in yeast infections, because they change skin pH. But there is no trial evidence so far that these, or any other home remedies, actually do anything very beneficial. Some of them might actually irritate, and one of them, tea tree oil, is associated with allergy in some people.

The better way to manage is with good old shampooing. The idea is simply to shed as many dead cells as possible, and a shampoo 2 or 3 times a week does the trick for most people. (More often than this can be counterproductive, though, because the skin dries out more.)

Ordinary shampoo should work. If it doesn’t, you can try shampoos that contain one or another of the over-the-counter medications that are known to reduce flaking.

Coal tar is one. It slows the rate at which cells grow, die, and shed. Some people are put off by the faintly tarry smell, however.

Salicylic acid, which is to say, aspirin, is another. This works as an exfoliant.

Selenium sulphide is yet another. It, too, slows cell turnover, and it seems to work against fungal overgrowth (that is, yeast) too.

Zinc pyrithione is a gentler alternative to selenium sulphide.

And finally, two antifungal agents, that work especially well on the kind of yeast you’re likely to have overgrowing, are ketoconazole and ciclopirox olamine.

Read shampoo labels and look for any of these. You can use them all freely, in as much quantity as you need. They’re safe. Because they may work a little differently for different people, you might try several of them, singly, and learn what works best for you.

One or another of these treatments will probably work. You may start seeing results in a few days, or it could take a couple of weeks.

When to seek medical attention

If your dandruff just doesn’t go away, no matter what you do, you might have a word with your dermatologist. There are other things to try, and there are possible underlying conditions worth checking for.

Obviously, if you try a new shampoo at home and you suddenly start itching or stinging, or you develop a rash, stop, and tell your doctor right away. Allergies and drug reactions don’t happen often with these shampoos, but they’re not impossible. Just keep an eye on what’s happening, and use some common sense.

Questions about your skin? Ask our dermatologists online for $35.