Assessment of skin irritancy: measurement of skin fold thickness

Abstract

More objective methods than visual scoring should be used for the assessment of skin irritancy reactions. The edema or fluid accumulation in the exposed skin sites can be accurately measured by a caliper and this alternative method of assessment is evaluated from different aspects. Sodium lauryl sulfate (SLS) and non-anoic acid in different concentrations were applied daily to human and animal (rabbit and guinea pig) skin and a dose-response relationship was established. Higher concentrations of the irritants induced an earlier response. With 5% SLS as the test substance and the increase in skin fold thickness as the single parameter of skin irritancy, the guinea pig was found to be less reactive than rabbit and man. Measurement techniques, reproducibility and advantges and disadvantages with different animal models are discussed.