It looks like eczema.

Some people call it neurodermatitis.

This is not easy to treat. The so-called "ancestral psoriasis, specialized in treating old Chinese medicine" refers to this type.

Generally speaking, Western medicine believes that it is caused by changes in the internal environment or exposure to abnormal substances on the surface of the skin, causing your own immune system to overreact and attack normal skin. It can be treated with hormonal drugs, such as urea ointment, etc. Indeed, this approach treats the symptoms rather than the root cause.

Traditional Chinese medicine does have a way to treat the root cause. In fact, it seems to regulate your internal environment through diet and medicine, and target the affected area through external application of medicines to remove dampness and heat, such as calamine.

My own experience is that adjusting eating habits and improving overall physical fitness are conducive to recovery. At least, I had it 8 years ago and it has never relapsed.