I. What is white nail syndrome? White dots and lines on the nails are called “white nail syndrome”. There are four types of white nail disease: dotted white nail, linear white nail, partial white nail and all white nail, of which dotted white nail is the most common. White nail – where do you come from? So far, there are many hypotheses about the production of white color, some people call white nail caused by nail plate lesions as true white nail; while those caused by nail bed lesions are pseudo white nail. The etiology of each type is different. 1. Punctate white nail: It is limited to the nail and can occur in normal people or by micro trauma, fungal infection and systemic diseases (such as typhoid fever, nephritis, trichomoniasis, etc.). Pitting white nail is chromosomally dominant. 2. Linear white nail: It can be hereditary or occur naturally in other nails. It is caused by trauma to the proximal nail perimeter and the nail matrix, mostly due to improper or excessive nail trimming. It can be longitudinal or transverse, with longitudinal lines moving from the nail root to the free edge, and transverse lines commonly seen in chronic arsenic poisoning, called Mees’ lines. They can also be seen in renal failure, heart failure, Hodgkin’s disease, malaria, etc. If all nails appear regular white horizontal lines is a characteristic of arsenic or thallium poisoning, similar horizontal lines are also seen in hydrochloric acid deficiency disease. 3. Partial white nail: mostly seen in tuberculosis nephritis Hodgkin’s disease frostbite, metastatic tumors and leprosy. If the proximal half of the nail is white and the distal half is red, pink or brown, with a clear demarcation line in the middle, this is called “opposite half of the nail” and is seen in patients with azotemia or some chronic uremic patients. 4, all white nail: relatively rare, with familial, all white nail is often chromosomal dominant inheritance, mostly congenital, generally do not need to be treated with drugs. It can also be complicated with typhoid fever, leprosy, liver cirrhosis, ulcerative colitis, nail biting and hairy nematode disease. In addition, exposure to nitric acid, nitrite and concentrated sodium chloride solution can cause white nail; fungal infection causes white nail mostly invades toenail. Do white nails need treatment? White nail itself does not need special treatment, but mainly to find the original cause and treat the cause.