There’s nothing more embarrassing than white flakes of dandruff in your hair or on your shoulders. The success of the many antidandruff shampoos available in pharmacies across the US shows us that this is a problem that affects many, many people. These efforts to avoid embarrassment are probably what pushed one fan of the show to send me this question through Twitter:
We should start with talking about what exactly causes dandruff. The main cause of dandruff is a condition called seborrheic dermatitis. It’s a condition of the skin and its cause is still unknown. Doctors think it may have something to do with the glands of the skin that produce a substance called sebum. Sebum usually lubricates and waterproofs the skin. In some people, this process may create an environment where a certain type of fungus called Malassezia can grow.
This then causes scaling of the skin, but studies haven’t been able to definitively show this fungus as the cause. Some scientists also suspect it may be an immune-related disorder similar to psoriasis. What we do know is that dandruff is unrelated to hygiene. If you have dandruff, it probably has nothing to do with how often you’re washing your hair.
Seborrheic dermatitis can show in places other than just the scalp. Finding scaling in these other areas can be a good way to confirm that’s what’s going on. Scaling on the face is often seen on the forehead, around the eyebrows and in the grooves on either side of your nose. In men, the beard areas are also often affected. Patches can also show up in sweaty areas like the armpits or between the thighs and are sometimes also found on the back.
The two theories about what causes seborrheic dermatitis reflect the treatments currently available. The most popular dandruff shampoos on the market use selenium sulfide, which is a chemical that kills fungus. Other shampoos with antifungal medications in them can also be found on the market, but are less popular because they are often more expensive.
Topical treatments aimed at the possible inflammatory cause involve using steroid shampoos, foams or creams on the affected areas. This will also help with itching that frequently accompanies the condition. While these sorts of creams shouldn’t be applied long term to skin on other parts of the body, the scalp has been found to hold up well with these treatments. Finally, tea tree oil, zinc pyrithione, coal tar and salicylic acid have all been used with moderate success, but the research on these is limited.
Unfortunately, seborrheic dermatitis isn’t a disease that can be cured, and it frequently comes back unless treatment is continued. The good news is that most people have good relief using one of the above treatments. It’s important to know you don’t have to use them every day as well. Studies of antifungal shampoos showed that using them once a week kept the issue at bay in 80-85% of people and using them once every two weeks kept scaling away in 70-75% of people.
The key message here is that if you suffer from chronic dandruff, which most dandruff is, the best thing you can do is find out what works for you. If one shampoo doesn’t work, try another. Make sure to look at the active ingredients first so that you’re getting a product that’s truly different from others you’ve tried. Once you find one that seems to work well, experiment with time between treatments to figure out what interval keeps the dandruff away the best without having to use it too often.
Unfortunately, without knowing the exact cause we can’t offer a cure. But with a little experimentation, you can probably find a solution that keeps your dandruff at bay.