Hi, I had Bells Palsy 8 years ago & unfortunately due to the doctor not giving me correct medication mine took around 6 months to get better, I still have nerve damage & facial tics, I felt ill whilst on the steroids but was not diabetic at the time, I advise rest, support & def do facial exercises when he's feeling up to it, I also have a friend who has had it several times, maybe 5? Hers recovers very well within weeks & she has no signs of it ever being there.