It is a purulent infection of the tissues 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 forms a sub nail abscess when it accumulates under the nail, which often becomes chronic inflammation after breaking down due to poor drainage. Let’s learn more about the causes of perineal nail infections. Excessive nail trimming (30%): If excessive trimming, especially on both sides of the nail and the skin tissue connected to the part is over-trimmed, or even trimmed to bleeding, the two sides of the nail edge to support the corneal tissue trimmed off too much, not easy to heal, if not pay attention to care, especially prone to inflammation, causing both physical and mental pain to patients. Therefore, it is especially important to remind the general public that when trimming nails, especially fingernails and big toenails, 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. Infection (20%): Perineal infections are mainly caused by nail infections. The nail is often caused by an abscess under the nail after a stab wound, abrasion, ingrown nail or pulling an “inverted prick” in the nail and nearby tissues, often caused by the spread of nail infection or infection caused by a stab wound under the nail or a nail hematoma secondary to a crush injury at the end of the finger, and the causative agent is mainly Staphylococcus aureus.