Quantification of cutaneous pharmacological reactions: comparison of laser Doppler scanning, colorimetry, planimetry and skin temperature measurement.
Palabras clave
Abstracto
OBJECTIVE
2-dimensional laser Doppler scanning distinguishes itself particularly by its good reproducibility with regard to both time and site. The aim of this study was to investigate this relatively new procedure in localised hyperaemic reactions and to compare it to already established techniques.
METHODS
We used a pharmacological test system with the rubefacient substances nonivamide, nicoboxil, a combination of these 2 substances as well as the inactive ointment base. Prior to and for up to 8 h after application of the test substances, measurements were made of the flow by means of laser Doppler scanning, the skin temperature by means of a probe thermometer, the colour of the skin by means of tristimulus-color-imetry and the area of erythema by means of planimetry.
RESULTS
With the parameters "maximum hyperaemic area" (laser Doppler scanning), planimetry and the a*-value of the lab.*-system (colorimetry), a significant difference was demonstrated between the combination of the active substances and the individual substances (p<0.0002; p<0.002; p<0.0469). The "maximum hyperaemic area" with laser Doppler scanning correlated significantly (p<0.0001) with the planimetrically determined area. The correlation coefficient was high (0.88≤r≤s0.92). The correlation between the "maximum hyperaemic area" and the * a-value was also significant (p<0.0001), but the correlation coefficient was smaller (0.64≪r≪.82).
CONCLUSIONS
In summary, in our test system, laser Doppler scanning, colorimetry and planimetry had the same ability to quantify cutaneous pharmacological reactions. Laser Doppler scanning, however, has the advantage that it can be used without any contact whatsoever with the skin.
