[Physiopathology of eczema]

Eczema is a skin inflammatory reaction mediated by antigen-specific T cells. Two main disorders belong to this group: contact dermatitis and atopic dermatitis. The pathophysiological mecanisms involved in both disorders are similar and include, at the cellular level, three elements: the antigen (hapten or environmental antigen), antigen-presenting cells belonging to the group of dendritic cells and antigen-specific T cells. The Langerhans cell responsible for antigen handling and presentation to specific T cells appears to play a central role for the generation of the inflammatory reaction.