We have tried both, my understanding is IVIG is the first course to try and then Rituxin. My son had two courses of IVIG two years apart, neither had results lasting more than a few days. He was nauseated and bad headache after each. He had rituxin 9 months ago, results were slow gradual and slow but he stayed above 165,000 for 8 months. June 11 platelets were 165,000, then June 22 we noticed suspicious bruising and they were 47,000, then on 7/2 30,000. We would have waited to see what would happen, but he had a camp scheduled this week so we did a pulse dose of Prednisone, 60mg for 5 days and yesterday they were 328,000. Not sure how long this will last but should get him through the week. Have you tried Whin Rho, did not help my son but others have had good results. Good luck, treatments work differently for each child, use your instinct.