Abstract: Crohn′s disease (CD) is a chronic nonspecific inflammatory disease. CD can affect any location in the digestive tract, and it also affect other organs, including the eyes, skin, liver and joints, which are termed extraintestinal manifestations (EIMs). The cutaneous manifestations of CD are common and occur in about onethird of patients. EIMs of CD have been divided into 3 categories. (1) Specific lesion, cutaneous manifestations of CD were the same as histopathologic findings of underlying gastrointestinal lesion. (2) Reactive lesion, it was also inflammatory lesion which was usually accompanied by underlying gastrointestinal disease while inflammatory injury was different from histopathologic findings of gastrointestinal lesion. (3) Associated lesion, it was caused by sequelae of human leucocyte antigen and chronic inflammation. In the current era of everexpanding therapeutic options for CD, some investigators have proposed a fourth category of EIMs, namely those that are therapyrelated lesion. The therapyrelated lesion is closely related to diseaseassociated conditions in light of certain skin findings, and there is potential overlap between them.