A recent study discovered the application of certain moisturizers increases the incidence of skin cancer in high-risk mice, but these animals were subjected to UVB radiation in high doses over a long period of time prior to application of moisturizers.  Four popular moisturizers were tested, providing the same result. It is not yet known if the same applies to humans. A fifth moisturizer, specially prepared without mineral oil and sodium lauryl sulphate , had no such effect.  The researchers asked Johnson & Johnson to produce this cream for the study, which the pharmaceutical company later patented. [ citation needed ]
Corticosteroids have been used as drug treatment for some time. Lewis Sarett of Merck & Co. was the first to synthesize cortisone, using a complicated 36-step process that started with deoxycholic acid, which was extracted from ox bile .  The low efficiency of converting deoxycholic acid into cortisone led to a cost of US $200 per gram. Russell Marker , at Syntex , discovered a much cheaper and more convenient starting material, diosgenin from wild Mexican yams . His conversion of diosgenin into progesterone by a four-step process now known as Marker degradation was an important step in mass production of all steroidal hormones, including cortisone and chemicals used in hormonal contraception .  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.
Weaker topical steroids are utilized for thin- skinned and sensitive areas, especially areas under occlusion, such as the armpit, groin, buttock crease, breast folds. Weaker steroids are used on the face, eyelids, diaper area, perianal skin, and intertrigo of the groin or body folds. Moderate steroids are used for atopic dermatitis , nummular eczema , xerotic eczema , lichen sclerosis et atrophicus of the vulva , scabies (after scabiecide) and severe dermatitis . Strong steroids are used for psoriasis , lichen planus , discoid lupus , chapped feet, lichen simplex chronicus , severe poison ivy exposure, alopecia areata , nummular eczema, and severe atopic dermatitis in adults.