I've been riding for over 40 years, and for nearly 30 of those years have suffered severe seat bone pain. It started when I was 25, after 12 years riding. Every time I got in the saddle, I would experience pain after a couple of minutes. After a long ride I would be left with sore, swollen patches on each seat bone. I tried different saddles, seatsavers, padded knickers, the lot. Nothing really helped, so I just put up with it, but it meant I couldn't do the really long rides I love. About 5 years ago, it gradually improved and after a few months I was fine again. Just recently, it has started again - only on longer rides at the moment, but I am terrified it will come back full force.
During this time, I was not able to wear ankle length boots because a similar reaction occurred on the backs of my lower leg where the boot touched, severe pain and swelling within minutes.
I am certain it's not muscular, so chiropractors, physios, etc. will not help. I think it may be something like an over-active bodily response to pressure in the bones. If it does come back, this time I'm going to see my doctor and hope maybe there is a steroid or cortisone treatment which will help. I desperately don't want to go back to the painful old days.