Quantitative evaluation of drug-induced erythema by using a tristimulus colour analyzer: experimental design and data analysis.

Pulsed-light reflectance using the Minolta Chroma Meter CR-200 was evaluated as a quantitative method for the noninvasive assessment of drug-induced erythema on the flexor surface of the forearm. Nicotinate esters were used as model vasodilators. Several parameters derived from the data were analysed using analysis of variance (ANOVA) and Tukey's multiple range tests appropriate for the study designs used. The effects of varying concentrations of methylnicotinate and of different nicotinate esters were found to be statistically significant. This non-invasive technique was found to be particularly useful in ranking the cutaneous responses elicited by the topical application of increasing concentrations of methylnicotinate in a single subject, as well as in a group of 6 volunteers.