Use of coumarin derivatives for the preparation of drugs for treating skin diseases

A compound of formula (I-1) wherein n equals 0 or 1, Z represents O or S, R1 represents one group chosen among the group consisting of hydrogen, C1-C7 alkyl, substituted, or not, by a halogen, a hydroxyl or a —O—R12 group, wherein R12 is a C1-C7 alkyl, a group —CH 2 —O—CO—R5 wherein R5 is chosen among a hydrogen atom and a C1-C7 alkyl, substituted or not by at least one halogen, a group —O—R13, wherein R13 is chosen among hydrogen and a C1-C7 alkyl, an amine or a —CH 2 -amine, R′1 represents a group chosen among hydrogen and —O—R14, wherein R14 is chosen among hydrogen and a C1-C7 alkyl, and R2 is chosen among the group consisting of a C1-C7 alkyl, a C3-C6 cycloalkyl, an aryl group, and an heteroaryl group for the treatment of pathologies involving excess activity of at least one member of the kallikrein family.