Evaluation of skin irritancy of sodium lauryl sulphate: a comparative study between the replica method and visual evaluation
- 1 March 1992
- journal article
- research article
- Published by Wiley in Contact Dermatitis
- Vol. 27 (3), 174-181
- https://doi.org/10.1111/j.1600-0536.1992.tb05248.x
Abstract
For 20 years, using the replica method, we have evaluated the skin irritancy of about 10,000 commercial products which come into contact with the skin. In this method, test substances are usually applied on the flexor side of the upper arm for 24 h by semi-open patch test. Subsequently, skin replicas are taken and skin irritancy is evaluated microscopically. In the semi-open patch test, test substances are not completely occluded as in the closed patch test. Thus, this method is less invasive than the closed patch test method to the tested subjects. In this study, we investigated the sensitivity of microscopic scoring (MS) of the replica and visual scoring (VS) of the skin. Sodium lauryl sulphate (SLS) at 0.02%, 0.05%, and 0.2% was applied on 20 subjects' upper arms, using closed and semi-open methods. In both the closed patch test and the semi-open patch test, the value of MS correlated with the concentration of SLS, while VS did not show such a clear correlation. In addition, we compared 2 clinical tests for skin irritancy which are commonly performed in Japan: VS of 48 h closed patch test reaction on the subjects' upper backs and MS of 24 h semi-open patch test reaction on the subjects' upper arms (replica method). MS on the upper arms resulted in a constant score, regardless of the location of application, while VS on the upper back produced results which differed widely depending on the location. Thus, the replica method is a useful clinical test for skin irritancy, because it is sensitive, reproducible and non-invasive.Keywords
This publication has 3 references indexed in Scilit:
- Post‐application occlusion substantially increases the irritant response of the skin to repeated short‐term sodium lauryl sulfate (SLS) exposureContact Dermatitis, 1989
- Different skin irritation abilities of different qualities of sodium lauryl sulphateContact Dermatitis, 1989
- Reproducibility of Patch Test Results: Comparison of TRUE Test and Finn Chamber TestPublished by Springer Science and Business Media LLC ,1989