How to help infected skin tag on my dog?

We have been having a problem with ticks in our backyard for awhile. So when I saw the reddish bump on my dog's leg I thought it was a tick and I tried to remove it. However, it turned out to be a skin tag. I feel really bad about that. I'm sure I was hurting him and I didn't know. It looks like its infected now. I put some antibiotic ointment on it, but is there anything else I need to do?