Emerging roles of adipose tissue in the pathogenesis of Psoriasis and Atopic dermatitis in Obesity

Abstract Obesity is a growing epidemic worldwide, and it is also considered as a major environmental factor contributing to the pathogenesis of inflammatory skin diseases, including psoriasis and atopic dermatitis. Moreover, obesity worsens the course and impairs the treatment response of these inflammatory skin diseases. Emerging evidences highlight that hypertrophied adipocytes and infiltrated immune cells secrete a variety of molecules including fatty acids and adipokines including leptin, adiponectin and a panel of cytokines/chemokines that modulate our immune system. In this review, we describe how adipose hypertrophy leads to a chronic low-grade inflammatory state in obesity, and how obesity-related inflammatory factors are involved in the pathogenesis of psoriasis and/or atopic dermatitis. Finally we discuss the potential role of antimicrobial peptides, mechanical stress and impairment of epidermal barrier function mediated by fat expansion, and dermal fat in modulating skin inflammation. Together, this review summarizes the current literature on how obesity is associated with the pathogenesis of psoriasis and atopic dermatitis, highlighting the potentially important but overlooked immunomodulatory role of adipose tissue in the skin.