Hi Davidl
I'm not able to give you an answer on prednisone itself but my experience with Hydrocortisone (H/C) (another corticosteroid similar to prednisone) may be useful for you. I'm on what's known as a maintenance dose of H/C: 25 mg daily for Addison's Disease (adrenal insufficiency) - I also have Trigeminal Neuralgia (confirmed) and PN (unconfirmed). The PN symptoms include burning feet, numbness - started in feet - now left hand, right leg, left ear etc. Recently needle-like stabbing pains have started all over. I also get shortness of breath and mild stomach pains. With the H/C I have to increase my dose if I get any sort of illness, injury or trauma. This can be anything from double to 10x the normal amount depending on severity. I have found that the TN was greatly reduced when I had to double the dose for about a week and completely disappeared temporarily when I had 10x (during appendectomy surgery last Oct) - it has come back but not as severe. However the PN numbness was unaffected by the increased dose - I self-monitored this while in hospital. This lack of response may be because of the type of PN I have (most likely auto-immune but possibly also with B12 deficiency and/or antibiotic use). I have read that corticosteroids have been successfully used to temporarily provide relief for some types of PN - sorry I can't remember where I read it or if it was for SFN. Someone will probably come along here that can give you more accurate info. If you decide to go ahead with the trial I hope you get some relief. Please come back and let us know how you get on.
Please note: 1mg Prednisone is roughly equivalent to 5mg Hydrocortisone