Testing for irritation with a multifactorial approach: comparison of eight non-invasive measuring techniques on five different irritation types.
BACKGROUND
Non-invasive bioengineering methods are widely used in the assessment of irritant skin reactions.


OBJECTIVE
To assess the ability of eight non-invasive measurement techniques to distinguish changes in skin conditions over time, these changes being induced by five different irritants.


METHODS
The following techniques were compared in a multivariate analysis: laser-Doppler perfusion imaging (LDI), laser-Doppler flowmetry (LDF), transepidermal water loss (TEWL), visual scoring (VS), colorimetric measurements (Chromameter CR 200 a* and L* scales), Mexameter Hb scale (Mexa Hb) and capacitance (Corneometer CM 820). Irritants tested were sodium lauryl sulphate 2% (SLS), tape stripping (TS), tretinoin 0.05% (TRET), ultraviolet (UV) exposure to 30 W m(-2) UVB/95 W m(-2) UVA, and dithranol 0.5% (DIT). Measurements were performed at baseline and after 24, 48 and 72 h. The study was conducted on the upper back of 11 healthy volunteers of both sexes aged 27-51 years.


RESULTS
For DIT it was possible to discriminate over time with CR 200 a* and L*, VS, LDI, LDF and Mexa Hb. In SLS discrimination over time was seen with TEWL and LDF. Discrimination in TS was demonstrated for TEWL, VS, CR 200 a*, CM 820, LDF, LDI and Mexa Hb. In TRET discrimination ability was seen for LDI, LDF, Mexa Hb and VS. For UV it was possible to discriminate using VS, TEWL, LDF, LDI and Mexa Hb.


CONCLUSIONS
Different irritation patterns need different measurement modalities in order to give optimal discrimination over time.
Fluhr
J W
JW
Department of Dermatology, University of Pavia, IRCCS Policlinico San Mateo, 27100 Pavia, Italy. joachim.fluhr@gmx.net
Kuss
O
O
Diepgen
T
T
Lazzerini
S
S
Pelosi
A
A
Gloor
M
M
Berardesca
E
E
D000328:Adult; D000704:Analysis of Variance; D000875:Anthralin; D002151:Calorimetry; D017453:Dermatitis, Irritant / Q000175:diagnosis* / Q000209:etiology; D004890:Erythema / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D007509:Irritants; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012720:Severity of Illness Index; D012867:Skin / Q000293:injuries; D012967:Sodium Dodecyl Sulfate; D014212:Tretinoin; D014466:Ultraviolet Rays; D014870:Water Loss, Insensible
D007509:Irritants; D012967:Sodium Dodecyl Sulfate; D014212:Tretinoin; D000875:Anthralin