The most common adverse reaction from omalizumab is injection site in duration, injection site itching, injection site pain and bruising but the package insert contains warnings regarding parasitic infections. While there are no reports of fatal anaphylaxis as a result of omalizumab, some cases have been serious and potentially life-threatening. Therefore, the FDA requires that people receiving omalizumab be monitored in the physician's office for a period of time after their injections.