Epidermal Permeability Barrier Defects and Barrier Repair Therapy in Atopic Dermatitis

gic disease in a process called the atopic march.The concept of atopic march was hypothesized to describe the progression of atopic disorders from AD in infants to asthma and allergic rhinitis in children.Kubo et al. 1 suggested a theoretical model of barrier disruption followed by percutaneous sensitization, which may apply to the pathogenesis of the atopic march.Therefore, the importance of barrier disruption in AD has gained increasing attention.In this review, we discuss the recent progress in understanding the functions of the epidermal permeability barrier, its immunologic role in human and animal subjects, and barrier repair therapies in AD. Epidermal permeability barrier dysfunctions in ADThe skin, as an interface between the organism and the external environment, plays a major role in protecting and supporting the life it encloses.The outermost layer of the skin, the stratum corneum (SC), is the primary mediator of this epidermal permeability barrier function. 8Atopic dry skin displays impaired Atopic dermatitis (AD) is a multifactorial inflammatory skin disease perpetuated by gene-environmental interactions and which is characterized by genetic barrier defects and allergic inflammation.Recent studies demonstrate an important role for the epidermal permeability barrier in AD that is closely related to chronic immune activation in the skin during systemic allergic reactions.Moreover, acquired stressors (e.g., Staphylococcus aureus infection) to the skin barrier may also initiate inflammation in AD.Many studies involving patients with AD revealed that defective skin barriers combined with abnormal immune responses might contribute to the pathophysiology of AD, supporting the outside-inside hypothesis.In this review, we discuss the recent advances in human and animal models, focusing on the defects of the epidermal permeability barrier, its immunologic role and barrier repair therapy in AD.