I've actually had a dry scalp, but when scratched no dandruff. I've also had dandruff, but not an itchy scalp. And, I've had a dry, itchy scalp with dandruff.

For me, if my scalp is itchy but no dandruff, then I need a tiny bit of oil massaged on my scalp. If I have dandruff, but no itchy scalp, then it's the product. If it's both, then I used too much product. At this point I usually dampen my hair, and rinse my scalp with water. The problem is gone.
Mod CG-Naturally Highly Porous and Dry
This list is not exhaustive...

Cowash: various
LI/Detangler: CURLS Cashmere Curls leave-in,
Moisturizer: Sebastian Potion 9 Wearable Treatment, Nu-Gro Moisturizing Spray
Stylers: Ouidad Wave Create Texture Taffy, various
Sealers: soon...

*experimenting and loving it!