Few things are more humbling than looking down at a black shirt and realizing your scalp has been shedding onto it all day. But if those flakes have you scratching your head — literally and figuratively — you’re far from alone.
Dandruff and seborrheic dermatitis are closely related, though experts don’t always define their relationship in the same way. And they're hardly niche problems: A 2024 meta-analysis of 121 studies and more than 1.2 million people estimated that 5.64% of adults worldwide have seborrheic dermatitis, while dandruff may affect roughly half of the population. So where does ordinary dandruff end and seborrheic dermatitis begin — and why does the condition keep coming back?
