Atopic dermatitis (AD) is a chronic, pruritic, relapsing inflammatory skin disease that has increased prevalence in industrialized countries. Growing evidence suggests that various defects in the innate immune system are associated with the development and severity of AD. Innate immunity comprises cellular and biochemical defense mechanisms that rapidly respond to the invasion of microbes or the release of endogenous danger molecules following recognition by pattern recognition receptors (PRR).

The primary components of innate immunity are physical and chemical barriers, such as epithelial and antimicrobial substances produced at epithelial surfaces. Circulating effector cells, such as neutrophils, macrophages, or natural killer (NK) cells, circulating effector proteins, such as complement components, and inflammatory cytokines can all regulate and coordinate many of the activities of the cells of innate immunity. The actions of innate immune responses impact the development of adaptive immunity. Alterations in both innate and adaptive immunity have been described in AD, leading to frequent infection, which triggers and aggravates the course of the disease. Immune regulation has a profound effect on the innate immune system, such as impairment of the skin barrier, modifications of PRRs, and regulation of immune cell function, facilitating the entry of allergens and infectious microbes into the skin.

The aim of this Special Issue is to gather research into innate immune regulation in atopic dermatitis. An improved understanding of innate immune regulation is able to offer us helpful insights into the pathophysiological processes of AD and support new therapeutic efforts. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Role of different PRRs in the pathogenesis of AD
• Infectious complications in AD
• Skin barrier abnormalities and cutaneous sensitization in AD
• The roles of innate immune cells in AD
• Complement activation in the progression of AD
• The effect of inflammatory cytokines and thymic stromal lymphopoietin (TSLP) on AD development
• The crosstalk between innate immune cells and epithelium in the setting of AD
• Cooperation between the innate and adaptive immune systems in AD
• Translational potential of emerging mechanisms of innate immunity in the context of AD