A few months ago, I developed a small whitish bump on my thumb I assumed was a wart. I've treated it twice with off the shelf salicylic acid, which seems to dissolve it for a while, then it grows back. I'm wondering if what I now have is still a wart, or some type of callus - a little circle of skin irritated by the treatment that has built up? If so, what should I do? Thanks in advance for any help.