Your immune system should do that for you. The actual question is, why isn't your immune system functioning properly? Chances are there is more going on with you. 80% of your immune system is in your gut. This more than likely means that you have been ignoring a digestive problem. You have to eliminate any foods that upset your gut and impairs absorption.
You need more than just one sympton to pinpoint causation. You must identify other symptoms other than just fungus on the face. Perhaps you have high blood pressure, stomach problems, gas, joint pain, hair loss etc.
Also be sure you are able to absorb the 90+ vitamins and minerals humans need to be healthy on a daily basis. Then be sure to eat them. Read my blog and my posts to find out more.