1, there is some black skin on the toe joint, which is very oxygen. Dig hard and the skin will fall off, and there is still a little water. New skin will grow back after a while. I have it on my finger, too Your condition is melanin deposition, not disease, but sub-health.

1. There is a kind of cell in human skin called melanocyte, which secretes melanin to protect the skin from ultraviolet rays, but when its protection task is completed, it will turn into dirt peeling off. When human metabolism is poor, some pigments will remain on the skin surface, forming dark spots.

2. The human body secretes pigments all the time, but during deep sleep, the hypothalamus will produce melatonin to remove the accumulated pigments on the skin. The two are in balance, so it can protect the stability of skin color.

3. In addition, irregular life, improper diet, emotional tension, ionizing radiation and endocrine disorders can also cause abnormal melanin secretion.

If you want to solve the problem completely, you can adjust your life rules, such as not staying up late to ensure a good sleep, eating more foods rich in vitamin C and vitamin A, such as lemons, preventing ionizing radiation and self-regulating emotions.

Good wishes!