Call 911 or seek emergency care immediately for signs of a severe allergic reaction, such as trouble breathing or swelling of the lips, tongue, or throat. Chest pain, fainting, a seizure, or severe confusion also require emergency care.
Seek prompt in-person care for a high fever, severe headache or neck stiffness, new or worsening muscle weakness, trouble walking or loss of coordination, facial drooping, heart palpitations, a widespread or spotted rash, persistent vomiting, or symptoms that are worsening quickly.
