[Immunopathogenesis of atopic eczema].

The role of elevated serum IgE in patients with atopic eczema has been unclear. It has recently been shown that antigens from house dust mites may penetrate the skin, bind to IgE on Langerhans' cells, which in turn mediate the activation of antigen-specific TH2 cells that are the predominant T cells found in early atopic skin lesions. TH2 cells produce IL-4, which stimulates the IgE production by B lymphocytes, and are chemotactic for eosinophilic granulocytes. The discovery of microbial superantigens that activate T cells more easily and less specifically than the traditional antigens do, helps us to understand how local microbial agents can provoke the outburst of new atopic skin lesions.