Sculpting details

I have completed a human head using sculpting. I smoothed the face. Now I have to put details like skin pores, blemishes, acne etc on top. I decided to use alpha map in sculpt mode. (I think height map is not that helpful and I have no knowledge on that. Bump map is not helpful because I can’t create details on a particular place. So rejected the idea of bump map and height map. Sticking to alpha map)
My computer can’t handle multiresolution at this stage. So I am using dyntopo and set the image of skin pore as texture to a sculpt brush.
But my problem is head is created. With each stroke it creates some geometry, I have to smooth it and this way the details of pore is getting vanished.
What is the solution?

If you want detail with geometry you need a lot of geometry, if you want details with out geometry you have to go with bum map You have to chose. (Cesar Salcedo use that and with great results) But Blender multiresolution works well, and you can go up as you need and if it gets unresponsive just delete that subdivision and you know the max you can do in your computer.