Multiple parameter assessment of skin irritancy.

In a previously developed guinea pig model for the study of skin irritancy, the irritant skin reactions caused by repeated open applications of low concentrations of sodium lauryl sulphate (SLS) have been studied macroscopically and microscopically. 2 new assessment methods, evaporimetry, which reflects the water barrier function of stratum corneum, and laser Doppler flowmetry to measure the cutaneous blood flow, have been added and compared with the existing methods of assessment in the model. In the present study of the irritant reaction caused by 1% SLS in 9 test animals, the 5 assessment parameters all showed values which, compared to control untested skin, increased progressively over the 3 days of application. In the assessment of skin irritancy, both evaporimetry and laser Doppler flowmetry have been shown to be useful non-invasive tools which can be quickly and reproducibly performed.