ABSTRACT
This chapter explores the relationship between psoriasis and diabetes at the levels of epidemiology, pathogenetic mechanisms, and treatment outcomes. It has to be realized that the relationship between psoriasis and diabetes in epidemiologic studies is bidirectional. It must be highlighted that not all epidemiologic data have documented a positive link between psoriasis and type 2 diabetes. Psoriasis is an inflammatory disease of the skin that has a strong autoimmune component, although the identity of the relevant autoantigens remains far from clear. A primary defect in the regulatory T-cell function has been implicated in the development of psoriasis. The important role of the Th17 response and the involvement of dendritic cells are well appreciated in both type 1 and type 2 diabetes. Skin-derived antimicrobial peptides have also been implicated in similar innate immune activation in psoriasis. In fact, glucagon-like peptide 1 analogues should be the preferred second-line antidiabetes agent after metformin for managing diabetes in patients with psoriasis.
