Modifications of the innate immune system in atopic dermatitis.

Atopic dermatitis (AD) is a frequent chronic inflammatory skin disease which is often complicated by recurrent microbial superinfections. Genetically based modifications which might have an impact on the innate immune system, such as impairment of the skin barrier, modifications of pattern recognition receptors, deficiency of antimicrobial peptides, antiviral natural killer cells and plasmacytoid dendritic cells, facilitate the entry of allergens and infectious microbes into the skin, where they encounter immunocompetent cells. The micromilieu in the skin of AD patients further potentiates dysfunctions of the innate immune system, leading to a vicious circle promoting the disease. This article provides an overview of modifications of the innate immune system in AD.