Bumps In my scalp

Doctor,
I am suffering from bumps in my scalp. I have been to the dermatologist, and he subscribed me shampoo. That shampoo is not working. It seems that these bumps keep coming back and will not go away. I try to pick them out of my scalp. I am very tender headed. There are alot of them, since I can't see my scalp, I have no idea as to what they look like while they are in my head. After I pick them out, I notice that they are hard, white, brown,red, or black sometimes. When I crush them in my hands after I pick them out they break apart like dandruff.
Doctor, I need to know what these bumps are and why they keep showing up in my scalp. Is there a way I can stop them from coming back?

[jagesh50]

More like a seborrheic scalp.Ketoconazole shampoos help.