Hey guys!!

Can anyone try to explain to me how to tell acne from foliiculitis. In particuluar the one caused by fungus! I have it on my upper back, mostly shoulders, some little itchy whiteheads on my chest, and ONLY I repeat ONLY my forehead has very painful little cysts that pop in a few days and are full of blood/pus. I can't seem to tell if its acne or not? I've never had these kinds of pimples and I never had body acne until last June. I'm also very curious as to why its only on my forehead. I do have VERY oily skin- which I heard is like a breeding ground for folliculitis. Can someone help?! How do you know?!

Here are some pics! what do you think?