I swear by these! I am posting a link to show you, but you can generally find these even in drug stores. They help itch, massage and stimulate your scalp without messing up your dreads as long as you don't go crazy with it. ; ) Make sure the ends of the wires are smooth with no barbs as to not catch on your dreads. I checked them out in the store to make sure. They have heavy duty ones, which I don't recommend because the wires are thicker. The cheap small ones with thin wires are the best! You will be very happy to have this around! Enjoy!
http://www.amazon.com/Scalp-Massager-Colors-May-Vary/dp/B001IHXFQK