Dermatology Question

Hey there, I am currently a Pre-Vet student, but was hoping to get some feedback on my own pet. Her case has stumped 3 veterinarians (excellent ones! btw). Maggie is a 9 year old Scottish terrier. Starting at age 3 she displayed pododermatitis of the front paws only (she chewed them). She was treated for environmental allergies and put on a limited anitigen diet. For the next 3 years she was continued to be treated seasonally for the same problem. At 6 yrs old a lesion on her chest appeared. She was treated with a steroid. Shortly after her front paws began to bleed. A cytology showed demodex. She was given 4 mitaban dips. This cycle of demodex outbreaks has continued since then, with out a specific pattern. They occur at all times of the year. She has normal blood work, is negative for Cushings. A full allergy panel was completed, and she is allergic to nothing.

Her current treatment includes using a follicular flushing shampoo and soaking paws with betadine. She is on oral anti-biotics, immunosupplements and a high quality diet. I have also tried alternative treatments, including neem oil and lavender oil. She continues to chew her paws, they swell, burst and slowly heal.

I appreciate any one who read through this entire thing! I would truly appreciate any suggestions or ideas! Thanks!