First, an allergy test must be conducted. Based on the results of the allergy test, the application of tetanus antitoxin is decided. The allergy test involves drawing 0.1 ml of antitoxin serum, diluting it with 0.9 ml of isotonic saline, and then injecting 0.05 to 0.1 ml of the diluted solution intradermally on the flexor side of the forearm. An equivalent amount of isotonic saline is injected on the other forearm as a control. Observe for 15-30 minutes. If there is no nodule or resistance at the injection site, it is a negative result. Patients with a negative result can have the rest of the original liquid injected subcutaneously. If a red nodule of about one centimeter or resistance appears at the serum injection site, the allergy test is positive. In this case, a desensitization injection is needed. The desensitization injection involves diluting the required injection fluid and the antitoxin serum with isotonic saline to ten times the volume and administering it subcutaneously in divided doses. After dilution to ten times the volume, which is 10 ml, the initial dose of 1 ml is administered, followed by 2 ml, 3 ml, and 4 ml, with each injection spaced 30 minutes apart until completed.