urticaria
"I had head to toe hives for the last 3-4 years.  Antihistamines did nothing.  After my first shot of Xolair, the hives went away for about 3 months.  Then after the 4th shot, they came back and stayed with me for another 3 months.  I just had my ninth shot and I've been hive free for 3 months.  I've put on weight that I can't explain and I'm having more foods give me gas.  These are not good side effects but better than the constant itching."