Hair Loss

Shyla has three spots where she has not hair. I took her to the vet and he gave me a cortisone/antibacterial ointment to put on them. They did a skin scrape and all they told me that it was not mange and must be an allergy. She can reach two of them which results in her chewing at them. The rest of her coat is beautiful and soft and shiny. It is bothering me because everyone looks at her like she has some disease. I have not changed food or anything else so I am feeling that it is possibly not allergies. Maybe ringworm? Anybody with experience with this? She is so great and I hate for her to look like this.