Both dandruff and scalp psoriasis can cause dryness, itchiness, and a flaky scalp, so you should see your doctor if you’re not sure what you’re dealing with.
The difference with scalp psoriasis, compared to dandruff, is that it’s long-lasting (chronic), more scaly than flaky, and it can spread past your hairline to your forehead or the back of your neck.
Dandruff is a harmless skin condition, whereas scalp psoriasis is an autoimmune disease caused by white blood cells attacking your skin cells.