urticaria
"I developed CIU approximately 4 months ago, and have never gone a day without extensive hives except when on prednisone, and the first 3 weeks after my first Xolair shots.  Since then, I have had two more rounds of Xolair, but the hives are not going away, and I'm terribly disappointed.  Have not given up the other antihistamines prescribed by my allergist.  Does anyone know how long Xolair takes before it starts knocking out the hives?"