Well then it may have a wilt. I would move it away from your other peppers or destroy...tough to treat.
Edit: Trash the soil too.
Edit: Trash the soil too.
As a precaution I would spray copper on all your plants and keep a close eye on the ones with the symptoms. As far as I know there is no remedy for bacterial leaf spot, once a plant has it it's there. If it gets really bad I'd pull them so they don't affect the others because you won't get quality fruit or yield from the infected ones....so Im assuming this is a bacterial spot. I sprayed with copper, so hopefully that'll take care of it.
As a precaution I would spray copper on all your plants and keep a close eye on the ones with the symptoms. As far as I know there is no remedy for bacterial leaf spot, once a plant has it it's there. If it gets really bad I'd pull them so they don't affect the others because you won't get quality fruit or yield from the infected ones.
I feel like the grim reaper in this thread but I'd rather error to the side of caution. I had a wilt that totally wiped out my tomatoes years ago and to grow the next years crops I replaced the soil in my beds.