Hi Sven,
This is probably my case, I have been having many health issues for about 2 decades and although the AI tests have been negative, it is highly likely that the etiology in my case is autoimmune, since this is the only thing that might explain all the problems that I have had (some of them are rare), and immunological treatments helped me before.
I was “lucky” to had Lymphoma, otherwise I wouldn’t have tried these treatments. The protocol for the Lymphoma included Rituximab, high dosage of steroids and some others drugs that are used to treat severe autoimmune disorders. This treatment helped not only the Lymphoma but also everything else, so when my fatigue, POTS etc., got much worse and I got the SFN diagnosis my doctors thought that it is worth to try Rituximab again. And it worked! ((-:

If I were in your place I would try to consult with Dr. Oaklander. From what you write I guess you have seen her lecture that was published here a few weeks ago. She mentioned their study in juvenile SFPN and as far as I remember IVIG helped 80% of the participants even though some of them didn’t have any AI markers.

Regarding the costs of IVIG, when my doctors recommended this treatment (I haven’t got it since my HMO refused to fund it and approved Rituximab) they spoke about getting 25gr (it depends on your weight) each day for 5 consecutive days, and then once a month. As far as I know each infusion cost about 2.5-3K.

I am also on a sick leave, without a clear diagnosis, I miss my work, and struggle to do whatever I can to return to it. I hope that after the next course of Rituximab I would be able to work again, at least part time..

I hope you would find a way to return to work