It is a purulent infection of the tissue around the nail caused by a minor local injury. It starts with redness, swelling and severe pain on one side of the nail or at the nail root, and then gradually becomes purulent and accumulates under the nail to form an abscess under the nail, which often becomes chronic inflammation after breaking down due to poor drainage. Perineuritis is usually caused by nail infections due to careless nail trimming. The first manifestation is localized redness, swelling, and heat pain. There are usually no systemic symptoms. The infection then spreads to the area around the nail root and under the nail. Early treatment of perineal nail infection is the key to overall treatment. Treatment can be done before the local inflammation spreads or as soon as there is local damage to the toe (finger) to shorten the course of the disease. Trim the nail reasonably during treatment to avoid injury. If there is a suspicious injury, it should be treated in a timely manner, and it is important to reduce the activity and wear loose socks and shoes to improve the treatment effect and shorten the treatment time. Acute nail infection is characterized by localized pain, redness of the skin, inflammatory reaction, and swelling of the skin around the nail, usually limited to a single segment. The onset of symptoms varies, usually occurring within 2-5 days after trauma. Fluctuations of the perinail skin abscess may not be observed early in the onset of symptoms. In the late symptomatic stage, the perineal skin abscess fluctuations may spread under the nail and involve the contralateral epineal and perineal skin. Abscess formation is seen under the nail plate, pushing the nail plate apart from the nail bed matrix; at this point it can be called perineal infection What are the causes of perineal infection Local minor injuries to the nail cause purulent infection of the perineal tissue, mostly caused by injuries during nail trimming, trauma, poor local hygiene, etc. Perinail infections are mainly caused by nail infections caused by careless nail trimming. If the nail is over-trimmed, especially the area on both sides of the nail that connects to the skin tissue is over-trimmed, even to the point of bleeding, and too much of the edge of the nail that supports the corneal tissue on both sides is trimmed off, it does not heal easily, and if care is not taken, it is especially prone to inflammation, causing both physical and mental pain to the patient. Therefore, the general public is especially reminded that when trimming nails, especially fingernails and big toe nails, special attention should be paid to moderate trimming: that is, do not trim too short and never hurt the parts of the nail that are connected to the skin tissue on both sides, as long as regular moderate trimming is maintained. In addition to nail trimming, there are other factors that can cause periapical nail infections: for example, periapical nail infections caused by the hollow caused by decaying gray nails; periapical nail infections caused by the nail being squeezed by the narrow front tip of the shoe. The high incidence of perineal nail infections occurs from September to October each year, with the number of cases approaching half of the year. The majority of patients believe that nail infections are not a major disease and will be cured without seeing a doctor. Therefore, the best treatment period is missed. On the other hand, nails should be trimmed reasonably during the treatment process to avoid injury. Once there is a suspicious injury should be treated promptly, appropriate to reduce activities, wear loose socks and shoes to improve the effectiveness of treatment and shorten the treatment time.