Atopic dermatitis: New therapeutic considerations

Atopic dermatitis is a genetically determined inflammatory condition in which the primary defect is expressed in one or more hematopoietic cells that infiltrate the skin. It is a multifactorial disease with inflammation triggered by a variety of factors. Among these, atopic dermatitis has been experimentally induced and reproduced by emotional-stress interviews and food challenges only. The inflammatory events of atopic dermatitis appear to be initiated by mast cells, but eosinophils, monocytes, and T lymphocytes (predominantly CD4) also are present in lesions. The secondary effects of inflammation are a dry, brittle stratum corneum and pruritus, causing excoriation and a lichenified epidermal layer resulting from chronic rubbing. Therapeutic approaches to atopic dermatitis may be directed at several points in the evolution of the disease. Agents including emollients are needed to preserve and restore the stratum corneum barrier, and effective antipruritics are required to reduce the self-inflicted damage to the involved skin. Various other agents may be needed to antagonize mediators or cytokines and to inhibit cytokine expression and release from lesional, immune-effector cells. Likewise, new phosphodiesterase inhibitors, calcium-active agents, and antiallergic drugs may be used to reduce the quantity and pathologic functioning of inflammatory infiltrating cells in the skin.