The purpose of the present invention is mainly to provide a medical skin external preparation that is suitable for treating superficial skin infections, in particular, superficial skin infections accompanied by blisters or erosions and the like. The present invention may provide a medical skin external preparation containing 1-cyclopropyl-8-methyl-7-[5-methyl-6-(methylamino)-3-pyridyl]-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid and/or a pharmaceutically acceptable salt thereof as an active ingredient, and containing an alcohol and/or a fatty acid having 12 or more carbon atoms.
