Hello ritz,
This may help. Twice in 18 months, I have had a " bad week" after IVIG.
The first episode came on during the infusion, and to all extents, it looked like a viral illness. It had a mild fever, with severe muscle aches, progressing that night to severe night sweats. (The muscle pain and night sweats are also the prodromes for my SCLS attacks). When I was alomst at the point of hospitalising, I took 15mg prednisolone, and within an hour, I could feel this all starting to abate. It lasted 2 days.
The second episode came on 2 days after the infusion. The same thing, - fever , severe sweats, and muscle pain. I took prednisolone 15mg daily for 4 days, and got better. At the time, I didn't have time to be ill! lol.
These are unlikely to be allergic reactions to the IVIG, as they only happen very occasionally.
They are possibly viral contaminants in the batch.. Unlikely.
It is possible that the batches had less of the relevant immune globulin, and they were thus ineffective.
At this stage, I continue my IVIG, and get trigger happy with the steroid at the very first prodomal signs.. Body aware is good.
John