if u have demodex and it got to the point where mites started causing skin problems you need to start treatment, there are few options available to treat demodex but the best way is use of natural products -
it takes time to treat demodex therefore if you choose to treat demodex with chemical based products, keep in mind that long use of chemicals have severe side effects, chemicals and antibiotics suppress the immune system. Weak immune system is the main reason why demodex mites start to multiply in the first place so try to avoid chemicals and use natural products. If you have severe demodex, you should use cream Demodexin along with natural anti demodex shampoo made by Ovante, these natural products help to control demodex and treat demodicosis. You need to wash you face with special anti demodex cleanser as well and avoid over drying because dry skin will
Have the doctors been unable to identify the parasite? Seems to me that's the first order of business or you'll never be able to treat it properly.
I don't think it's demodex mange either. That's a mite that destroys the hair follicle and doesn't bother humans. Sarcoptic mange mites on the other hand, CAN infect humans - also known as crabs. Both of these mites are well known and easily identifiable which makes it doubtful that they are what you're dealing with.
Get copies of all pathology reports and use that as the starting point of your research. Best of luck to you - you truly have my sympathy!
Seems you have picked Dog Community as there is no Item listed on MED-HELP to cover mange-like skin problems in humans