Irritants in combination with a synergistic or additive effect on the skin response: An overview of tandem irritation studies

Abstract

Sodium lauryl sulfate (SLS) has often been chosen as a model for irritant contact dermatitis (ICD) to study the effect of irritants in combination b1 b2 b3 b4 b5 b6 b7 b8 b9 b10 b11 b12 b13 b14(1-14). Recently 'tandem', or sequential, exposures with SLS have been performed to study the mechanism of skin barrier impairment in ICD b1 b2 b3 b4 b5 b6 b15(1-6, 15). The assessment of reactions have been documented with visual scoring, transepidermal water loss (TEWL), skin colour reflectance measurements, skin blood flow; among which TEWL has been noted as the most sensitive value (b1616). The matched control groups were treated with either a single exposure to a single irritant or in tandem with the same irritant repeatedly. Synergistic and additive effects have been reported for various tandem pairs of irritants, however, the mechanism for both remains unclear. The results of tandem irritation studies were evaluated to define and investigate the responses produced and deduce a possible mechanism of action. Clinical ramifications, albeit complex, are discussed. © 2006 Blackwell Munksgaard.