What It’s Like Living With Chronic Hives

Severe allergic reaction. A severe allergic reaction called anaphylaxis can happen when you receive XOLAIR. The reaction can occur after the first dose, or after many doses. It may also occur right after a XOLAIR injection or days later. Anaphylaxis is a life-threatening condition and can lead to death. Go to the nearest emergency room right away if you have any of these symptoms of an allergic reaction: 
•wheezing, shortness of breath, cough, chest tightness, or trouble breathing 
•low blood pressure, dizziness, fainting, rapid or weak heartbeat, anxiety, or feeling of “impending doom”
•flushing, itching, hives, or feeling warm 
•swelling of the throat or tongue, throat tightness, hoarse voice, or trouble swallowing