Provided is an external medicine for treating trichophytosis unguium, said external medicine being a non-coating type external medicine for treating trichophytosis unguium containing a medium-chain fatty acid triglyceride as a non-volatile component, which shows a high nail permeability, has excellent drug efficacy and formulation properties and, therefore, is clinically applicable. More particularly, provided is an external medicine for treating trichophytosis unguium which comprises a substance having antifungal activity such as efinaconazole, a volatile component, an additive such as a medium-chain fatty acid triglyceride and a permeation promoter such as ethyl lactate. This preparation shows a remarkably improved nail permeability and has excellent characteristics as a medicine from the viewpoint of drug efficacy and formulation properties.
