• Woolly hair is very curly hair that is characteristically unruly and will not form naturally into locks. Woolly hair nevus first appears when the scalp hair begins to grow. It is seen as a patch of unruly, very curly hair, arising in a field of otherwise unremarkable scalp hair. Woolly hair can also be seen as a hereditary trait involving the entire scalp and in acquired forms. It may be distinguished from two other types of unruly hair, pili torti and spun glass hair.
(Arch Dermatol 114:233-238, 1978)