How much florinef is he on?   My 6 year old SWCAH daughter is on .05mg per day (half a tablet).   The thing with the salt wasting part of CAH is that children have varying degrees and require varying amounts of florinef.  However, I would think that high blood pressure would indicate too much florinef and this can be very dangerous.   Talk to your Endo about this as soon as you can.