My Xolair Experience I have severe asthma/allergies. Your IgE level (blood test - Immunoglobulin E - which is the 'allergy' antibody) is measured and that, along with your weight is used to determine your dosage. Technically I am in the 'do not treat' range due to my very high IgE level, but my pulmonologist decided to try it anyway. I was started on Xolair when I was 18 years old, and am now 20, and it is my understanding that Xolair is not yet FDA approved for those 12 and under. I am still on Prednisone, but notice a BIG decrease in symptoms since starting Xolair. It took about 13 months or so for me to start seeing improvements, but I also had a HUGE Anaphylactic rxn and asthma flare that required 2 long hospital admissions for IV steroids shortly after starting the Xolair. So it could just be that my body was recovering from that so I didn't notice Xolair benefits right away. However, since the time that I have noticed these improvements I haven't been using Xopenex (nebulized bronchodilator). My doctor says it works for me short-term, but it ends up over-sensitizing my lungs, and I get VERY tight from it. So the improvements could be from not using Xopenex anymore.