MEASUREMENT OF CUTANEOUS ERYTHEMA BY MEANS OF PHOTODENSITOMETRY - APPLICATION TO CUTANEOUS PHOTOSENSITIVITY

We have developed a photodensitometry method to evaluate the intensity of cutaneous erythema objectively. The method measures the optical de nsity of photographic slides of cutaneous erythema. It combines techni ques used commonly but separately by investigators: diffuse transmitta nce spectroscopy (which is a variant of diffuse reflectance spectrosco py) and photography. We have used this method to study photosensitivit y in 22 volunteers who received increasing doses of ultraviolet radiat ion to the back. Our work confirms the usefulness of an important para meter in photobiology: the regression slope of the curve representing the erythema index, a function of the logarithm of the dose applied.