I have several knots on my scalp of different shapes and sizes.they itch and oozes puss.my hair continues to grow. i first noticed a knot on my scalp back in 2000, but it appeared to go away. later on more began to appear. they did not bother me during th

This : This is very difficult to answer without a clinical examination. Possiblities might include pilar cysts, sebaceous cysts, lipomas, moles, skin cancer, lymph nodes, infections (bacterial or fungal), prurigo nodularis, or other possiblities. Sorry i can't be more specific so i would recommend you see a dermatologist. I hope that helps a little!