Kitty with unknown skin issue needs a specialist

We saved these two beautiful sisters from a farm where they would've been used as dog bait.

About a year ago Robin (the lighter coloured Calico) started getting little sores in her neck. She started scratching and scratching and just didn't stop. After a while she had scratched all the skin off her entire neck and even on her head and face.

We panicked about this and rushed her to the vet in the area, where we were just told it must've been fleas and she was given a flea treatment.

In the next week it just became worse, so we took her to another vet that has a good reputation. With them we went through everything possible. The vet did a biopsy which only revealed that she has an allergy. Not what for, just an allergy. We then started trying everything we could think of. We changed the bowls to different materials, changed the kitty litter, cleaned and fogged the entire house for fleas, moved to another house, put her on two different specialised diet foods. We have even stopped using ANYTHING with fragrance in the house, from our anti-perspirant to our soap to home cleaning supplies.. All that helped was giving her a long lasting cortisone injection, which lasts for about two weeks before she starts scratching again.

At this stage we are feeling absolutely powerless. We have to wrap the poor kitty with bandage every single day and clean the wounds where she scratches around the bandages to keep it from getting infected.

We have recently tried homeopathic histamine medicine but it just made her drowsy all the time and made her depressed.

Then in June 2019, we saw her sister, Mavis (the darker Tortoise shell kitty) started also getting sores. She did recover from it at least but she is itchy now and then.

So we think this has to be a genetic problem between the sisters. None of our other kitties have these issues, but they try and help by cleaning the wounds, which makes it worse.

We have run our credit cards into the max with this and need to try and get these two little sisters to a veterinary dermatologist. We have Johannesburg Specialist Veterinary Centre in mind but they are expecting an initial cost of around R3000. Plus then we will have to do trials with expensive flea and tick control, specialized diets, medicines, etc. until we get to the root cause. We are hoping that he would be able to finally solve this so we can give them the life they deserve, without pain.