Question) Will using a specialized shampoo help improve dandruff and scalp inflammation?

I'm always worried because my scalp isn't clean.
I've been fighting off dandruff, and I can see blood marks on my scalp like this.
I need to go to the dermatologist, but I haven't been able to go yet.

I've been told to use Head & Shoulders shampoo for dandruff, but what kind of shampoo should I use for blood stains? Should I use a specialized shampoo prescribed by a dermatologist?