I had this too anc two docs told me it was just excoriations (lesions) from scratching/picking at scalp. It felt at times like ants were crawling under my scalp. I got a few little scabs from picking.
Doc #2 ate her words. I got her to take a culture of it (does not hurt!). It came back from the lab as Staph Aureaus. HIGHLY CONTAGIOUS! (This means it is MRSA virus which can become very serious if it invades tissues). I had suffered more than 4 months with this "imagined" scalp condition.
She put me on a new antibiotic and shortly after taking it I wound up going to the ER by ambulance with deep, boring and nbearable bone pain. The ER docs told me that the MRSA virus had gotten into my system but my Dermo still feels it was a reaction to the meds which I was pulled off of.
Here is what she then recommended -- and it worked! Use Body Wash with Tea Tree Oil as a shamppoo (your hair comes out very clean and soft). The concentration of Tea Tree Oil MUST be no less than 5% and up to 15% is better. I got it at either Bodyworks or Body Shoppe at the Mall. You can also get 100% Tea Tree Oil and add it to your own shampoo provided its "pure". There are lots of articles about this on the web.
You MUST shampoo every day and leave the shampoo with tea tree oil on your scalp for 5 minutes. Tea Tree oil is a natural antibiotic.
But--before you go this route, tell your dermatolgist that you suspect it's staph aureus and request that he or she takes a culture!!
I get this too. Isn't it annoying. I find if I wet my hair in the morning and tie it up the itching is less. My hair is still wet in the evening. I also find it is worse in some seasons and worse on some medication. I believe mine is an allergic reaction to pollen or something. I have a dilute steroid lotion that is useful when it's really bad.
Take care.