The present invention provides an excellent composition (e.g., a drug, a quasi drug, a cosmetic) for skin diseases treatment use. The composition for skin diseases treatment use according to the present invention contains an exosome secreted from a stem cell (e.g., an adipose-derived stem cell), the composition being characterized in that the stem cell is one containing a drug-encapsulated nanoparticle in which a drug (e.g., statin, estrogen, retinoic acid, ascorbic acid) is encapsulated in a nanoparticle containing a bioabsorbable polymer.
