You might notice some white flakes on your collar or an itchiness that seems relentless, no matter how often you wash your hair. Dandruff isn’t exactly a desirable condition, but it’s also quite common—about half of the population deals with it at some point.
An itchy, flaky scalp isn’t harmful, but it can certainly be a nuisance. So, what’s behind those flakes? Here’s a rundown of potential causes, ways to manage it, and when you should consider seeking medical advice.
What causes dandruff?
Dandruff is essentially a mild version of a skin condition known as seborrheic dermatitis, which involves inflammation typically affecting the head, face, or trunk. In more severe cases, it presents itself as patches of red skin adorned with tiny, greasy scales. However, most individuals with dandruff experience only slight scaliness without any redness, primarily affecting the scalp.
Experts aren’t completely certain about the exact causes of dandruff. It’s likely that multiple factors come into play. One of the main culprits seems to be a yeast called Malassezia, according to James Pathoulas, a dermatology professor at the University of Minnesota. This yeast usually resides harmlessly on the scalp, but an overgrowth has been associated with inflammatory responses in the scalp.
Rather than pinpointing a single cause for seborrheic dermatitis, Natasha Mesinkovska, an associate professor of dermatology at UC Irvine, suggests thinking of it as a system that is out of balance. The health of your scalp is determined by a “trifecta” of factors: the organisms living on your scalp, its ability to prevent those organisms from penetrating deeper skin layers, and the skin’s immune response to them.
Who gets dandruff?
There’s no clear reason why some individuals develop dandruff while others do not. Genetics might have something to do with it—research has linked it to at least 11 gene variants. Environmental conditions like hot and humid weather or even intense exercise can also influence its onset.
Hormonal fluctuations that increase oil production may exacerbate symptoms, especially during puberty, pregnancy, or menopause.
What should I do about it?
If you notice mild scaling on your scalp without significant redness or itching, using an over-the-counter dandruff shampoo can be effective. Common active ingredients include zinc pyrithione, selenium sulfide, and ketoconazole. These all work well to reduce Malassezia levels, calm inflammation, and control flakes.
Pathoulas suggests thoroughly massaging the shampoo into your scalp and allowing it to sit for a few minutes before rinsing. It’s advisable to use it about three times a week, and you can follow up with either your regular conditioner or one specifically designed for dandruff. On days you don’t use the medicated shampoo, your usual shampoo and conditioner are just fine.
Watch out, though—ketoconazole and selenium sulfide may dry out your hair and increase the risk of breakage, especially for those with dry, textured, or curly hair. In such cases, you might want to consider a milder, sulfate-free zinc pyrithione option geared toward textured hair.
It’s a good idea to avoid fragrances when possible, as they can cause scalp allergies. Natural scents can also lead to reactions, so it’s worth being cautious.
Once you’ve got your symptoms under control, many people find they can cut back on using the dandruff shampoo to just once a week. If your usual shampoo stops working after being effective for months, it might mean the yeast has built a resistance. Switching to a different active ingredient temporarily might help reset that balance.
When do I need to see a doctor?
If you see improvement with a medicated shampoo but the flaking returns within days after stopping, this indicates that the underlying issue may need more attention, according to Mesinkovska.
Look out for thick, red, sharply-defined patches with silvery-white scales, which are more indicative of psoriasis than common dandruff, especially if similar patches appear on other areas like elbows or knees. If redness or flaky skin develop in different areas of your body, it could suggest an allergic reaction. Regular dandruff shampoos won’t be effective against these conditions.
Symptoms like hair loss or a burning sensation accompanying the flakes are not typical. If you experience these, it’s essential to consult a healthcare provider regarding potential scarring alopecia.
For those with ordinary dandruff that doesn’t respond to basic treatments, there are prescription options available. Experts recommend ciclopirox shampoo, which is antifungal and has some antibacterial properties, as well as prescription-strength ketoconazole. A newer treatment, Roflumilast, can be applied to a dry scalp as a foam.
Some researchers are exploring the idea of altering the scalp’s bacterial populations, potentially introducing beneficial bacteria to crowd out the problematic ones. However, this research is still in its early stages, so for now, experts don’t advocate using things like yogurt or kombucha on the scalp.
