seborrheic dermatitis

n.
  1. A chronic form of dermatitis characterized by oily scales, crusty yellow patches, and itching, and occurring primarily on the scalp and face.dyssebacia pityriasis alba seborrheic dermatosis
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.