In the ideal sequence of events in developing a drug, one would first select a particular disease and then proceed to learn sufficient relevant facts about it (the first difficulty); then, one would know how to predict which particular chemical structure would have the required therapeutic effects without toxicity (the second difficulty); one would then synthesize the drug (perhaps difficult but probably possible); then, one would have valid and reliable testing models of the disease in animals (not presently known for any skin disease); after proof of efficacy and safety, finally the drug would be tested in the clinic (possible). Such a sequence has never been accomplished. The etiology of inflammatory diseases, particularly, is known to a limited extent only, and the dermal manifestations of them are understood still less. The pharmacologist therefore has many good opportunities here for rewarding work.