When the infection spreads to the entire nail groove, it is called perineuritis. It is often caused by secondary infections such as prick pulling, stabbing, nail root fracture or injury during nail trimming, or sometimes by finger sucking in children. It is commonly caused by Staphylococcus aureus infection. Clinical manifestations Initially, some skin folds appear red, swollen and painful, and then gradually spread to the whole nail groove, sometimes forming subepidermal abscesses, and sometimes invading the nail below to form sub nail abscesses, nail groin infection and sub nail abscesses can be transformed into each other or exist simultaneously. Chronic nail sulcus can also be seen clinically, with a slow course, mild redness, swelling and pain, prominent inflammatory granulation tissue at the nail edge or nail groove, only a little purulent discharge, easy abrasion and bleeding, and separation of part of the nail from the nail bed. Prevention Educate and train children in good hygiene habits and proper hygiene, such as washing hands regularly, not sucking fingers, trimming nails regularly and not too short, applying oil in winter to prevent dry skin, and avoiding skin damage. When the barbed skin is sticking up, cut off the thorns in time so as not to peel the nail longer and deeper and cause secondary infection. When the nail root skin crack or keratinized thorns occur at the two corners of the nail root, after washing hands with soap, local cleaning and disinfection with tape closed protection, tape tarnished need to be replaced in a timely manner, should be removed from the proximal to distal direction of the finger tape, so as not to tear the skin crack large infection formed nail infection. Treatment Nail fungus can heal on its own, or it can rapidly septicize. In the early stages, non-surgical treatment can be used, such as soaking in hot water for half an hour five or six times a day, or washing the hands and applying antibiotic ointment and gauze wrapping. When a subepidermal abscess is formed, the epidermis of the abscess can be cut out, coated with medicine and then wrapped with gauze. When a subcutaneous abscess is formed, an incision at the lesion is used to drain the pus. In case of subcutaneous abscess, the nail should be removed as appropriate to allow thorough drainage. In chronic nail fungus, the nail should be removed and the overgrown granulation tissue should be cut.