I Have Developed Small (smaller Than A Dime) Slightly Raised

i have developed small (smaller than a dime) slightly raised areas on my scalp. similar to a welt but more crusty.
they don't bother me except the whole scalp is itchy. the best I can tell, these areas are basically pink, and/or flesh tone and basically are completely hidden by my hair. First I had one, then two, and now probably six or seven. what could they be??