A ratchet-controlled micrometer screw gauge has been used to measure the changes in skin thickness produced by topical corticosteroids.
Measurable thinning of the mouse ear followed repeated daily application of corticosteroids. This response in the animal was used to assess the atrophic potential in a variety of standard formulations. The same compounds were applied to human skin and the changes in thickness measured.
Patterns of response and the rank order of thinning obtained from the animal model were found to parallel closely the human results.