The use of carbon dioxide slush as an exfoliating agent originated with Giraudeau1 in 1925. The first report in the American literature of the use of cryotherapy in the treatment of acne was made in 1939 by Karp, Nieman and Lerner.2 They reviewed the literature to date and reported on the treatment of 50 of their patients with acne and acne scars.
Dobes and Keil3 reported their results in the treatment of 115 patients with acne. Only 7 with acne scars were treated in their group, and the results were unsatisfactory.
Hollander and Shelton4 reported favorably on a series of 36 patients with acne scarring treated by cryocautery, with an average of twenty applications per patient. They judged their results by "patient reaction." Patients were questioned by an impartial member of the staff and the findings recorded statistically. They regarded cryotherapy as a method of distinct