The danger triangle may become infected when scratched by nails. The danger triangle is the area from the corners of the mouth to the base of the nose, which can become infected if scratched by nails. A break in the skin can lead to infection, especially if the scratch is not treated properly. Infections are often caused by bacteria, and pathogens can enter the body through breaks in the skin or bloodstream. Nail scratches in the Danger Triangle are particularly important for intracranial infections because the Danger Triangle is connected to the intracranial venous sinuses, which can cause intracranial infections if infected, and need to be taken seriously. After the triangle of danger is scratched by the nail, you should clean the wound in time, keep local hygiene, and go to the hospital in time, under the guidance of the doctor for treatment.