Acne vulgaris (AV) is a very common skin disease that affects the general population. Previously it was considered that the AV is an infectious disease, but recent studies confirm that the AV is a chronic inflammatory disease in which Propionibacterium acnes and innate immunity plays a key role. The skin is the interface between the body and the environment. It consists of the epidermis and dermis, and hypodermis, subcutaneous fat, supports it. The epidermis is the outermost skin structures consisting of a multilayered epithelium. The uppermost layer of the epidermis is the Stratum corneum (SC), the final product of keratinocytes proliferation and differentiation. The term "epidermal barrier" refers to the overall result of multiple physiological functions of the epidermis, many of which occur in the SC. The harmony of multiple barrier function of the SC maintains the structural and functional integrity of the skin. The changes or disturbances of any portion of the epidermal barrier may cause the clinical manifestations. Contemporary literature supports the concept that the VA is associated with the inherent abnormalities in the epidermal barrier function. Also, the treatment of AV can induce changes in the epidermis and disrupt its physiological function.