 This study compared the efficacy of topical 10% urea cream and 0.025% tretinoin cream in treating acanthosis negricans, a condition characterized by hyperpigmented skin on the neck and intra-trigenous areas. The results showed that 0.025% tretinoin was significantly more effective than 10% urea in improving neck hyperpigmentation, with 63.2% of participants treated with 0.025% tretinoin having more than 75% skin improvement compared to 36.8% of participants treated with 10% urea. This article was authored by Ruchatri Sirachod, Suthida Chaitreyanan, Thitiwat Chaykul, and others.