I recently noticed a bald spot on the front left limb of my indoor cat. I don't know if it's ringworm or an allergic reaction. The other day, I did give her advantage 2 flea medication on the base of her neck. I read that balding could be a symptom but it's usually at the place of application. In my case, that isn't the case so I'm really wondering how this happened. I got a good look at the bald spot and it's like it's been shaved off- the hair loss is not gradual or anything like that. There are 2 bumps, on gray and one white. The spot seems to double in size though. Do you guys have any idea what it is? Should I be concerned and start isolating her just in case it's ringworm? My day off is Wednesday so I can't take her to the vet today or tomorrow. I've uploaded pictures.