What is wrong with my dogs skin ?

http:// (image description) At 5 months my puppy started losing her hair. The vet did a skin scrape and said its puppy mange. We were given antibiotics, special shampoo, and a sulfar dip to use weekly. Its been 3 months with no relief. She doesn't itch more than usual. We started immune bites and removed chicken from her diet still with no relief. Amy thoughts on if its mange and alternative treatment?