The way I understand it is that steroids (cortef, prednisone, etc) do supress your immune system if they are taken by non CAH patients pharmacologically. That would mean cortisol above and beyond what the body produces. For CAH patients, steroids are physiological doses to mimic the body’s secretions, not add to it.  The pharmacy has to put that label on the bottle because they don’t \know what it is used for.  My daughters take Cortef for CAH at a physiological dose and have a great imune sysyem, I on the other hand take prenisone for hives and have a terribly suppressed immune system. Hope this helps.