J. Aramaki et al., Which bioengineering assay is appropriate for irritant patch testing with sodium lauryl sulfate?, CONTACT DER, 45(5), 2001, pp. 286-290
For testing with sodium lauryl sulphate (SLS), measurements of transepiderm
al water loss (TEWL) and cutaneous blood flow with laser Doppler (LD) are c
onsidered to be the most reliable methods. The aim of this study was to det
ermine which method of measurement should be preferred when conducting SLS
testing under varying conditions. Patch testing with SLS at different conce
ntrations and exposure times was performed. TEWL values were compared with
those of LD. TEWL values showed distinct changes at low SLS concentrations
and short application periods. By contrast, higher SLS concentrations were
necessary to increase LD values. Short application of patches changed TEWL
rather than LD values. When evaluating SLS patch testing by bioengineering
methods, TEWL measurement appears to be more suitable for a test procedure
that provokes mild skin reactions (SLS concentration <1%), whereas LD measu
rement is more appropriate to evaluate pronounced skin reactions (SLS conce
ntration greater than or equal to1%).