Transitory blanching of nonacral skin has been observed after contact with a 3% solution of H2O2. This phenomenon was reproducible in all tested whites, but was not reproducible in black skin. Blanching developed within 30 to 300 seconds after contact with H2O2 and lasted from 10 to 30 minutes. It is proposed that the topical application of H2O2 induces a transient vasoconstriction of vessels in the superficial dermis.