[Help] I recently adopted a dog from the shelter and he's been persistently licking his leg. Today I found an odd looking bump (pic attached) and just to ease my worries before I take him to the vet this week, have any of you had a dog with this?

picWhen we first noticed his licking was too persistent, we put the collars on him to prevent him from licking, and we bought a bandage to wrap around the area he kept licking at. This dog has some anxiety issues so even when I covered up the main spot he'd lick, he'd just end up persistently licking other parts of his body. But today I noticed that the spot that he mainly picked at, grew some type of red bump. This will be the first time I take him to the vet for a health issue so I just want some feedback so I'm not a huge mess until the appointment. Thanks so much via /r/dogs http://ift.tt/2sGezvr