The mode of topical immunomodulators in the immunological network of atopic dermatitis

For a long time, therapeutic strategies of atopic dermatitis (AD) have been dominated by the application of local or systemic steroids or other immunosuppressive agents, which have been limited by their potential for unwanted local or systemic side effects. Recently, the use of a new generation of topical nonsteroidal, immunomodulatory drugs has revolutionized the therapeutic options of this often recalcitrant allergic-inflammatory skin disease. Research work has focused on the identification of the exact mode of action and the immune specificities of the so-called 'topical immunomodulators' (TIMs) such as tacrolimus and pimecrolimus in AD. In addition to the previous findings about the mode of action of TIMs on T cells, other target cells of TIMs such as keratinocytes, mast cells, eosinophils and dendritic cells have been identified recently as potential therapeutic targets. In this overview, we provide a research update about the anti-inflammatory and anti-allergic properties of TIMs on effector cells of AD that may be involved in the complex pathophysiology of AD.