I was prescribed Deriva BPO gel for my moderate acne, but after using it, my skin got really irritated. I know the irritation might settle down after a few weeks, but I also noticed a dark line around one side of my lip. Its not going away, and Im worried if this could be a permanent dark patch or if itll fade on its own. What should I do?

It's likely a side effect of the deriva bpo gel known as post-inflammatory hyperpigmentation, which can occur as a result of skin irritation or inflammation. In most cases, this dark patch should fade over time once you stop using the gel. To help speed up the process, you can try using a topical skin lightening cream containing hydroquinone or kojic acid.