Effect of a Dihydroxyacetone-Based Camouflage Agent on Ultraviolet-Induced Erythema

Vitiligo is an acquired, idiopathic skin disease of dyspigmentation, affecting approximately 0.5%-2% of the global population. However, it is not clear whether dihydroxyacetone (DHA)-based camouflage could affect the effectiveness of ultraviolet (UV) therapy. Therefore, we aimed to investigate the effect of a camouflage agent containing 3.6% DHA on UV-induced erythema.

Fifty-one healthy volunteers of skin type III to IV who came to the hospital were recruited in this study. A 308 nm excimer UV lamp was used to perform the minimum erythema dose (MED) test on the lower back and a camouflage agent containing 3.6% DHA was applied. Four groups were tested on the same individuals (subjects served as their own controls), including no camouflage nor irradiation (Group A), irradiation without camouflage (Group B), camouflage without irradiation (Group C), and camouflage plus irradiation (Group D). Refined MED was evaluated via naked eyes (erMED) and digital dermatoscopes (drMED), The erythema index (EI) value of the targeted site was measured by dermatoscopic digital imaging and analyzed.

After the camouflage masking, 43 (84.3%) subjects remained unchanged in erMED, 7 (13.7%) had a MED increase of one grade (+10 mJ/cm²), and only one (2.0%) had a MED increase of two grades (+20 mJ/cm²). Although statistically significant differences were observed in MED (p = 0.0047) and EI values (p = 0.0015) between groups with and without camouflage, these differences were clinically minimal. No significant difference was observed between erMED and drMED in Group B (p = 0.157) or D (p = 0.317).

The camouflage agent containing 3.6% DHA exhibits statistically significant but clinically negligible effects on erythema in volunteers exposed to 308 nm UV light, requiring no dose adjustment in 84.3% of cases.