I find that sitting still and lying down cause my SFN symptoms to worsen. Mine is from above knee to feet, shoulders to hands and even over my scalp and face. My symptoms are mostly like sunburn and some loss of sensation. I take pregabalin 100 mg three times daily and Oxcarbazine 150 mg three times daily. I am T2D and the doctors suspect that as the root cause. I moderate carbohydrate intake for the most part but have found that if I indulge and let my glucose levels get high, i.e., over 180 then my SFN symptoms seem to flare quite a bit. I haven't found anything on the Internet or a doctor to confirm this, but it does seem to be true for me. I have read that the medical community is finding that SFN is showing up in patients that are pre-diabetic. So, even if you are not currently diagnosed diabetic does not mean that that is a contributing factor.