Redness and swelling at the edge of baby’s toenail is considered to be a possible case of onychomycosis, which can be treated with general treatment, medication and surgery. Trenchitis is a purulent bacterial infection of the nail groove and its surrounding tissues formed along the sides of the nail, often caused by tiny puncture wounds, contusion, reverse peeling, or cutting the nails too deep. Often first occurred in one side of the nail groove subcutaneous, first for the local redness, swelling, heat, pain, pus occurred in the nail groove subcutaneous white pus, fluctuating feeling, but not easy to break, can spread to the nail root or the other side of the nail groove. Nail groove inflammation has not yet pus, local can be given ultrashort wave, infrared and other physical therapy. Abscess formation should be operated, along the paronychium longitudinal incision drainage. Nail root abscesses need to be separated and pulled out part or even all of the nail, and care should be taken to avoid damaging the nail bed during the operation, so as to facilitate nail regeneration. In daily life, it is necessary to pay attention to the baby’s nails should not be cut too deep, to avoid stabbing and so on. If there is redness or swelling at the edge of the baby’s toenail, it should be promptly consulted and evaluated by a specialist.