Assessment of erythema and skin perfusion by digital image analysis and scanner laser Doppler.

Background/aims: In the present study, a model for measuring the intensity of skin erythema by computer-assisted digital image analysis (DIA) was elaborated. The DIA technique was compared with laser Doppler perfusion imaging (PIM) to evaluate the relationship between erythema and skin perfusion.
Methods: To produce erythema, three different types of nicotine patches (Nicotinell®, Nicorette® and Nicorette® placebo) were randomly applied ventrally on the upper arms for the time period recommended by the manufactures. After removal of the patches, colour photographs for subsequent DIA were taken and laser Doppler scanning for PIM was performed. The relationship between PIM and DIA was estimated intra- and inter-individually.
Results/conclusions: A statistically significant linear correlation between PIM and DIA data was found, but the relationship was relatively weak. This may be explained by the fact that DIA and PIM are influenced by different physiological factors such as skin chromophores and velocity of moving cells. The results strengthen the theory that erythema and perfusion measurements reflect separate physiological phenomena and that the methods should be considered complements to each other in the experimental situation.