I have the 20% tca. I did a dark spot on my elbow and it turned brown but just wasn't peeling so I peeled it off. Now it is darker. I understand I should've left it alone. I have 2.5 weeks off work next month and I'm planning to do my face. Last night I did a small area in front of my ear where I have some dark spots. It burned right away and turned red but I didn't see it frost. I left on for five minutes. I really won't have anymore time off after this so I want to make sure I frost this time. Any advice? I started using maxi-peel #2 a few days ago. I've also been using porcelain serum which has hydroquinone in it for about a month. I have fitz4 skin I believe. I have issues with PIH, hence the reason I want to do peels and remove the brown spots. I'm a picker and my face shows it.