Is there any proven remedy in TCM for psoriasis?
Yes, but proper diagnosis is key - (see "What Does Acupuncture Treat?") to better understand the concepts behind treating the "causes" not the "symptoms".
So my recommendation is to find a practitioner in your local area, get proper diagnosis and treatment and you should do well. Treatment can take anywhere from 7-10 treatments to treatments spaced over many months depending on your case, your diet and lifestyle and many other factors.