Background: Treatment-related changes in hyperpigmentation are difficult to quantify with visible light photography, especially when the changes are subtle.

Objective: Our purpose was to determine the utility and reliability of fluorescence photography to measure changes in mottled and diffuse hyperpigmentation.

Methods: Thirty-two subjects, with mildly to moderately photodamaged skin, completed a 36-week, double-blind, vehicle-controlled study of tretinoin cream 0.025%. Clinical evaluation of hyperpigmentation as well as standard flash photographs and fluorescence photographs were obtained at baseline and week 36.

Results: The fluorescence photographs were evaluated blindly and yielded macule counts that decreased significantly from baseline in tretinoin-treated subjects compared with vehicle-treated subjects (31% vs 11% decrease; p = 0.02). Diffuse hyperpigmentation, as evaluated from the fluorescence photographs, decreased 16% from baseline for tretinoin-treated subjects and increased 5% for vehicle-treated subjects ( p < 0.01). No significant differences in mottled or diffuse hyperpigmentation were observed between groups through clinicalevaluation.

Conclusion: Fluorescence photography is a noninvasive method that is sensitive in the evaluation and quantification of distribution and changes of mottled and diffuse hyperpigmentation.

(J Am Acad Dermatol 1997;36:226-30.)