Nail fungus is just an inflammation of the nail-skin junction located on both sides of the nail, mostly due to ingrown nails, while perineal fungus is a continued aggravation causing inflammatory reactions around the nail and is heavier than nail fungus. Treatment can begin with disinfection with iodophor and alcohol scrubbing, and if it does not improve, surgical treatment is required. So, how to identify the two? The following is the differential diagnosis between perineuritis and nail fungus: Differential diagnosis: Perineuritis: a purulent infection of the tissue around the nail, which 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 an abscess under the nail when it accumulates under the nail, which often becomes chronic inflammation after breaking down due to poor drainage. Perineal infections are mainly caused by nail infections due to careless nail trimming. If the nail is trimmed excessively, especially the part of the nail that connects to the skin tissue on both sides is trimmed excessively, even to the point of bleeding, and the edge of the nail that supports the corneal tissue on both sides is trimmed off too much, which does not heal easily and is especially prone to inflammation if care is not taken, causing both physical and mental pain to the patient. The nail gouge: Mostly caused by the nail gouge and its nearby tissues stabbing, abrasion, embedded nail or pulling the “inverted skin spur” after the nail abscess, often from the spread of nail gouge infection or nail stabbing injury caused by infection or finger end crush injury caused by the nail hematoma secondary infection, the causative agent is mainly Staphylococcus aureus.