Seborrheic dermatitis vs dandruff — how to tell, and what to do
Dandruff is dry, superficial and easy. Seborrheic dermatitis is inflammatory, greasy and needs a treatment plan — not a shampoo.
Dr. Amara Okafor
Consultant Trichologist · Harley Street
In short
- Dandruff: dry, white, no redness. Fixable with the right shampoo.
- SD: greasy, yellow, red patches. Chronic and inflammatory.
- Both driven by Malassezia yeast; SD adds inflammation.
- SD often needs prescription antifungal + short-course topical steroid.
Dandruff and seborrheic dermatitis are on the same spectrum but sit at different points. Confusing them wastes months. Here is how a London trichologist tells them apart in three seconds.
Visual differences
- Dandruff: fine, dry, white flakes; scalp underneath looks normal
- SD: greasy yellow scale; redness underneath; often extends to brows, nasolabial folds, chest
- Dandruff: itch mild; SD: itch moderate–severe with burning
Treatment paths
Dandruff responds to zinc pyrithione (Head & Shoulders), selenium sulphide (Selsun), or salicylic acid shampoos. Two weeks of consistent use — most cases resolve. SD needs antifungal (ketoconazole 2% shampoo, prescription-strength), sometimes combined with short-course topical steroid or calcineurin inhibitor for the inflammation.
When to see a trichologist or dermatologist
Any of: SD extending beyond scalp; failure to respond to 4 weeks OTC; hair loss appearing in affected areas; symptoms started after a medication change.
If your dandruff is greasy and red, it isn't dandruff.
Frequently asked
Common questions
Can SD cause hair loss?+
Yes — chronic inflammation can drive TE. Not scarring, and reversible with control.
Is it contagious?+
No. SD is not transmissible.
Why does it flare in winter?+
Cold + central heating + reduced sun = Malassezia loves it.
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