I find your question interesting as we are experiencing the same problem. DS, 8 years-old, is 3 weeks post IVIG and things have never been this bad. From everything I've read and heard, I am not concerned that this is a permanent exacerbation caused by the IVIG, but I do wonder if it is or isn't a normal part of the healing process. Have others experienced a lengthy exacerbation followed by success? Or is it likely at this point that perhaps this wasn't the right treatment for him? We are desperate to hear others experiences with IVIG.