*2.4.4 Obesity-associated immune disorders affecting skin*

Normal adipose tissue in a nonobese person has a population of anti-inflammatory/regulatory immune cells: M2-macrophages and regulatory T cells. These are replaced by pro-inflammatory cells: M1 macrophages, Th1, Th17, and cytotoxic T cells in adipose tissue in persons with obesity [59]. Systemic immune adaptations in obesity include increased number of circulating monocytes, neutrophils, Th1, Th17, and Th22 cells. The pro-inflammatory cytokines produced by pathogenic adipose tissue (IL-1β, IL-6, IL-17, and IFN-γ) result in a chronic low-grade inflammation. Skin conditions such as psoriasis, atopic dermatitis, and eczema are strongly associated with obesity [60]. Hashba et al. [61] have suggested the association of lichen planus with obesity.
