Nail scratches on the arm should be sterilized, bleeding should be stopped, infection should be prevented, and medication can be used to promote wound healing to avoid scarring. After the arm is scratched by the nail, you can use saline to rinse the wound, and then use iodophor and other disinfectants to disinfect the local area, and if the local bleeding is not stop, you should put pressure bandage to stop the bleeding. In addition, the wound should be disinfected and dressed daily until it heals to prevent infection. If the wound becomes infected, drugs such as mupirocin ointment can be applied topically to fight the infection. After infection control, recombinant human epidermal growth factor gel, recombinant bovine basic fibroblast growth factor gel and other drugs can be used to promote wound healing. After wound healing, drugs such as compound heparin sodium allantoin gel and polysulfated mucopolysaccharides cream can be used to soften the scar tissue to avoid leaving scars. If your arm is scratched by a nail, follow your doctor’s instructions for treatment.