The present invention provides a solution for external use having antitrichophytosis activity and high nail permeability. A solution for external use for preventing or treating trichophytosis, the solution containing a coating formation agent, and a compound represented by the general formula [in the formula, R1 represents a hydrogen atom, C1-6 alkyl, or trilfuoromethyl； R2 represents a hydrogen atom, C1-6 alkyl, halogen, -COO (C1-6 alkyl), or (CH2)1-3COOR (R represents a hydrogen atom or C1-6 alkyl)； R3 represents a hydrogen atom, C1-6 alkyl, amino, trifluoromethyl, or OR (R represents a hydrogen atom or C1-6 alkyl)； R4 represents a hydroxyl group； R5 represents a hydrogen atom, C1-6 alkyl, hydroxyl group, or halogen； R6 represents a hydrogen atom, C1-6 alkyl, trifluoromethyl, halogen, amino, -NRaRb, nitro, hydroxy C1-6 alkyl, -CONRaRb, -COO (C1-6 alkyl), -COOH, -(CH2)1-3COOR, or ORa (R represents a hydrogen atom or C1-6 alkyl, and Ra and Rb may be the same or different and represent a hydrogen atom, C1-6 alkyl, or C1-6 acyl)； R7 is a hydrogen atom, C1-6 alkyl, -OR (R represents a hydrogen atom or C1-6 alkyl), or halogen； and R8 represents a hydrogen atom, C1-6 alkyl, hydroxyl group, amino, or nitro] or a salt thereof.
