DNA methylation and inflammatory skin diseases.

Epigenetics is the study of heritable changes in gene expression that do not originate from alternations in the DNA sequence. Epigenetic modifications include DNA methylation, histone modification, and gene silencing via the action of microRNAs. Epigenetic dysregulation has been implicated in many disease processes. In the field of dermatology, epigenetic regulation has been extensively explored as a pathologic mechanism in cutaneous T-cell lymphoma (CTCL), which has led to the successful development of epigenetic therapies for CTCL. In recent years, the potential role of epigenetic regulation in the pathogeneses of inflammatory skin diseases has gained greater appreciation. In particular, epigenetic changes in psoriasis and atopic dermatitis have been increasingly studied, with DNA methylation the most rigorously investigated to date. In this review, we provide an overview of DNA methylation in inflammatory skin diseases with an emphasis on psoriasis and atopic dermatitis.