Greenish yellow puss from a large pimple or boil that keeps showing up in the same place, what is it and how do i get rid of them

Epidermoid Cyst: Epidermoid cysts usually don't cause problems unless they get very large or the cyst wall ruptures, exposing the inside keratin to the surrounding tissue. This is a problem because the contents of an epidermoid cyst are very irritating to the tissue around the cyst. A ruptured cyst can get red, swollen, and painful. Your cyst has ruptured, see a surgeon.