Interleukin-6 and the skin.

Interleukin-6 is a pleiotropic cytokine with numerous biological activities. It is produced by normal constituents of the skin, including epidermal cells, fibroblasts and dermal endothelial cells. It is also synthesized by inflammatory cells infiltrating the skin in various pathological conditions. We reviewed the presumed activities of interleukin-6 in normal skin and in some diseases with cutaneous involvement. The action of some drugs used in dermatology was also considered with regard to the modulation of the cytokine release. It is concluded that several important cellular lineages of the skin release interleukin-6. The cytokine appears to play a crucial role in the pathogenesis of both local and systemic inflammation, tumor development and autoimmune diseases.