PID dose IVIG/PANDAS flare?

[LaraM]

My son has a primary immune deficiency, Celiacs disease, PANDAS, and lots of environmental/food allergies. He received his first dose of IVIG on Wednesday--only 10 grams for his weight of 56 pounds. This is much lower than the typical PANDAS dose, but is the dose for a primary immune deficiency. We saw amazing things on Wed., Thurs. and 1/2 of Friday (more articulate, not easily frustrated). Friday afternoon and today, he is struggling again. He bit his brother, is obsessing with our dog again, and is just generally showing a mild PANDAS exacerbation. Does this occur with IVIG (low dose)? Is it a temporary side effect or could it be something else? I am just trying to figure out if this is normal, if the PANDAS flare could be allergy related (we have seen this in the past) or what?? Thanks for your input!!