In 1952, . Peterson and . Murray of Upjohn developed a process that used Rhizopus mold to oxidize progesterone into a compound that was readily converted to cortisone.  The ability to cheaply synthesize large quantities of cortisone from the diosgenin in yams resulted in a rapid drop in price to US $6 per gram, falling to $ per gram by 1980. Percy Julian's research also aided progress in the field.  The exact nature of cortisone's anti-inflammatory action remained a mystery for years after, however, until the leukocyte adhesion cascade and the role of phospholipase A2 in the production of prostaglandins and leukotrienes was fully understood in the early 1980s.
Oral steroids enter the bloodstream to get to the lungs, so they can cause these and other systemic effects, particularly if used frequently or for long periods of time. Other effects include cataracts, increased blood sugar, lack of blood supply to some bones and suppression of the body's own production of steroids needed during stress. Since inhaled steroids reduce the amount of oral steroids that may be needed for asthma, they may be safer than just using as needed mediation in all but the mildest forms of asthma. If your child is given many courses of oral steroids, careful monitoring for some of these side effects may be necessary.