Tetanus is widely used clinically and is formally known as tetanus antitoxin. Therefore, if a patient is injured and the wound is deep, such as reaching the subcutaneous fat layer or even the muscle layer in severe cases, it is necessary to prevent tetanus infection by injecting tetanus antitoxin. Before injecting the tetanus antitoxin, it is mandatory to perform a skin test to prevent the patient from experiencing allergies, even severe clinical symptoms such as anaphylactic shock. During the skin test, generally, 0.1ml of tetanus antitoxin is diluted in 0.9ml of saline, and a skin test is performed on the forearm, observing for at least half an hour.