A little bit of facial numbness after an IV may be caused by drug side effects, allergic reactions or certain diseases. 1. Drug side effects: some people may be more sensitive to certain drugs, such as antibiotics, etc., after infusion may appear facial numbness, numbness of the limbs and other symptoms, the infusion should be stopped. 2. Allergic reaction: certain drugs can cause allergic reaction, such as penicillin, etc. Allergy is usually manifested as itching, rash, and sometimes local numbness. 3. Disease-induced: if the patient himself suffers from certain diseases, such as facial neuritis, there may be symptoms of facial numbness, the symptom may not have much to do with whether to play the drip, and the disease itself. Facial numbness after playing drip, should seek the help of doctors in time, clear reasons, so as not to delay the condition.