Skin barrier defect in atopic dermatitis: increased permeability of the stratum corneum using dimethyl sulfoxide and theophylline.

The existence of a defect in the skin barrier of patients with atopic dermatitis (AD) was demonstrated and its importance in the pathogenesis of AD was emphasized. In order to evaluate the penetration properties of the stratum corneum of AD patients, the in vivo skin response to the penetration of dimethyl sulfoxide (DMSO) and in vitro response to the penetration of theophylline utilizing a diffusion chamber were studied. Both methods demonstrated an increasing level of penetration through the epidermal stratum corneum, with greatest penetration being evident with lesional skin, followed by AD non-lesional and then the normal control. However, statistical significances existed only between non-lesional and lesional skins in the case of the DMSO test, and between the normal control and non-lesional skin in the case of the diffusion chamber analysis using theophylline. Increased penetration of a non-specific nature is important in the pathogenesis of AD.