All you can do is try L-Glutamine and Slippery Elm along with getting a chiropacter to check your mid dorso region of the spin. Urine therapy both internal and topical helps alot. Internally so much Urea gets converted into L-Glutamine which helps strengthens intestines amongst other things. So ideally you should fast and do Urine ideally! Also try adding Himalayan salt to your diet following Dr Batmanghelidj's advice. I'm going through a similar event my friend and its annoying as hell but I hope to give results eventually. Mine started from an injured area I thought had healed to a point hmmmmmm. Also try high dosage Omega 3 fish oil. Also increase your intestinal flora (good bacteria) with a quality natural product like Kombucha tea and do multiple liver flushes. If your suffering from inflammation etc try rubbing in extra virgin olive oil. You can try Curcumin which comes from Tumeric and its a Cox inhibitor which means it blocks one of the Cox's and that cox it blocks is the promotor of Inflammation.

You said:"After visiting several dermatologist, I am convinced why dermatologist can not cure this, they don't care....".
How right You are!
I have done 20 year battle with scalp condition. Docs prefer to call it psoriasis.
"We can't cure it but we can treat it!"

Question: Do You have any problem with Your fingernails?

I suspect a foreign orgamism is the culprit and i am half way proving that.
About 6 months ago i managed to reduce the area down to 50%.
At this time it is too early to say if it really is Psoriasis as docs say.
I don't know if there is a test for that or not. None of the doctors, and there are many that i visited, ever performed a lab analysis.
I will soon take my hair out once more and apply the harsh treatment to it for next 2-3 weeks. One of the component in that treatment is hydrogen peroxide to kill the micro-organism simultaneously from the scalp and from the fingernails.

You can experiment with hydrogen peroxide and see if it helps.

Good luck
SF