The efficacy and safety of 20% urea cream and 10% urea cream in the treatment of acanthosis nigricans in adolescents, a randomized comparative double-blind study

Abstract

Background: Acanthosis nigricans is commonly associated with obesity. It is characterized by brown-black skin thickening on the neck and the flexural areas. This study aimed to assess the efficacy of topical 20% urea cream compared to 10% urea cream in the treatment of acanthosis nigricans in adolescents. Material and Methods: A randomized comparative, double-blind study was conducted on participants aged 12–18 years with acanthosis nigricans of the neck. Treatment efficacy was assessed via narrowband reflectance spectrophotometer, while the overall success rates at weeks 2, 4, and 8 were evaluated by the investigator- and participant-assessed global evaluation scales. Results: A total of 40 participants with acanthosis nigricans were enrolled and completed the study. Throughout the period of 8 weeks of treatment, 20% urea showed greater improvement of hyperpigmentation compared to 10% urea (p = 0.001), with 22.5 ± 11.9% and 10.7 ± 8.1% improvements, respectively. Findings from the overall global evaluation scales were consistent with the results from the narrowband reflectance spectrophotometer. Treatment with 10% urea and 20% urea was well-tolerated without any local serious adverse reactions. Conclusion: Urea cream improves neck hyperpigmentation associated with acanthosis nigricans in adolescents, in which the 20% concentration shows superior efficacy to the 10% concentration. © 2021 Wiley Periodicals LLC