Patent ID: 7494503

Claim:
An acne prevention method comprising: exposing tissue to a first light source, the first light source comprising light emitting diodes emitting light at a wavelength of from about 300 nm to about 1300 nm and a total energy fluence of less than 4 J/cm 2 ; and applying a topical chromophore composition to the tissue either before or after exposing the tissue to electromagnetic radiation to prevent acne, wherein the topical chromophore composition has at least one absorption maximum between 300 nm and 1300 nm and comprises an active ingredient selected from the group consisting of chlorophyll, porphyrin, and combinations thereof, wherein the active ingredient has at least one metal-ligand bond, wherein the metal in the metal-ligand bond is selected from the group consisting of Fe, Mg, Cu, Al, reactive transition metals, metal chelates, and antibody complexes.