Fever from a tetanus shot: what should you know?

Tetanus vaccination can leave the injection area sore and may be followed by tiredness, headache, chills, or a raised temperature. These effects reflect immune system activity and usually improve without special treatment. A fever is not the same as tetanus disease, which is linked to painful muscle stiffness and spasms rather than simply feeling warm. A wound, another infection, or a separate illness can also cause fever, so the whole picture matters.

Encourage fluids, rest, and loose clothing. A cool, comfortable room may help, but avoid ice baths and rubbing alcohol on the skin. For discomfort, check with a pharmacist or clinician before using paracetamol or another medicine, especially for a child, pregnancy, liver disease, or other regular medicines. Follow the product directions and do not combine products that contain the same ingredient. Keep the wound clean and follow the advice given after the injection.

Call emergency services for breathing difficulty, throat or facial swelling, widespread hives, fainting, severe weakness, or a seizure after the injection. Arrange prompt medical review if the fever is high or persistent, the person becomes confused or hard to wake, vomiting prevents drinking, urine becomes unusually infrequent, or the wound becomes increasingly red, swollen, painful, or drains pus. A clinician should also assess new muscle stiffness or spasms. For vaccination details, see Tetanus Vaccination.

Ask how long this reaction may be observed, how to measure temperature accurately, which medicine is appropriate, whether the wound needs review, and when the next tetanus dose is due.