it could be Alopecia Areata...
try this link..
(or just in google images search for Alopecia Areata)
it shows images from people who have it.. if you have look the same go to a doctor (I read this could be treated and in some cases healed).. I'm 30 years old and I have male baldness pattern.. (try this another link to see if you have it)..
http://images.google.com.mx/images?g...attern&spell=1 (or just in google images search for Male Baldness pattern)
About KP on scalp.. I used to have Foliculitis (it's a little bit like KP but this can be healed with pills and special shampoos)..