Quantitation of erythema by reflectance spectroscopy

A fiber optics bundle was added to a Pye-Unicam scanning spectrophotometer allowing its use in quanti-tating erythema in vivo. Standard chamber irritation test sites were evaluated subjectively by a trained observer and objectively by quantitating the relative absorption of green light (570-580 nm) due to the presence of the hemoglobin chromophore. There appears to be a good relationship between subjective erythema scores and spectrophotometric readings. Reflectance spectroscopy rovides a valuable objective adjunct to the subjective evaluation of skin irritation