Sm. Patil et al., CUMULATIVE IRRITANCY IN MAN TO SODIUM LAURYL SULFATE - THE OVERLAP PHENOMENON, International journal of pharmaceutics, 110(2), 1994, pp. 147-154
Repeated contact of skin with surfactants causes irritation often char
acterized by dryness, erythema and scaliness. Morphologically healed s
kin after preexposure can still evoke a stronger reaction to any subse
quent exposure of an irritant. Cumulative irritancy using the overlap
phenomenon was studied. The effects of repeated and prolonged applicat
ion of sodium lauryl sulfate (SLS) on human skin in vivo (healthy adul
t volunteers) were evaluated using non-invasive techniques of TEWL and
skin capacitance measurements and visual scoring. The inability of TE
WL and skin capacitance to achieve pretreatment values 2 weeks post SL
S treatment suggests the possible detrimental effects of SLS on skin l
ipids. The surfactant effect was cumulative and dehydrating effects on
prolonged and repeated application were observed.