Comparing the efficacy and safety profiles of 0.025% and 0.05% tretinoin creams in treating acanthosis nigricans: a randomized double-blinded study.

Acanthosis nigricans (AN) is a skin disorder with hyperpigmented and velvety plaques without a standardized treatment regimen. We aimed to compare the efficacy and safety profile of 0.025% and 0.05% tretinoin creams in managing AN. An 8-week, randomized double-blinded study was conducted in adults with AN. Participants were instructed to apply tretinoin cream on their posterior neck. Narrowband reflectance spectrophotometry was used to measure skin improvement through melanin (M) and erythema (E) indices at each follow-up visits at weeks 2, 4, and 8. Improvements in Acanthosis nigricans scoring chart (ANSC), investigator- and patient-global evaluation (IGE and PGE) and adverse cutaneous irritations were also scored. Both the 0.025% and 0.05% tretinoin creams were efficacious in acanthosis nigricans treatment with 17.1 ± 8.0% improvement and 18.4 ± 9.8% improvement after 8 weeks treatment by reflectance spectrophotometry measurement, respectively. There were generally no significant differences in efficacy, improvements in ANSC, IGE, and PGE scores, and local cutaneous irritations between the two groups. The 0.025% and 0.05% tretinoin demonstrate similar efficacy and safety profiles in the management of AN. Both concentrations are well tolerated with mild degree of local cutaneous irritation.