title: The Efficacy and Safety of 4-n-butylresorcinol 0.1% Cream for the Treatment of Melasma: A Randomized Controlled Split-face Trial.
abstract: BACKGROUND
  Melasma is a common acquired symmetrical hypermelanosis that occurs on sun-exposed areas, and it is frequently observed among women. Various treatment modalities have been tried, but none are completely satisfactory. 4-n-butylresorcinol, which is a resorcinol derivative that has an inhibitory effect on both tyrosinase and tyrosinase-related protein-1, was introduced in 1995 and it has received increasing attention as a new hypopigmenting agent. However, the hypopigmenting effect of 4-n-butylresorcinol in human subjects has only been shown in a few studies.
  
  
  OBJECTIVE
  The aim of this study was to investigate the hypopigmenting efficacy and safety of 4-n-butylresorcinol 0.1% cream for the treatment of melasma.
  
  
  METHODS
  Twenty patients with melasma were enrolled to this randomized, double-blind, vehicle-controlled, split-face comparative study. The patients were instructed to apply 4-n-butylresorcinol 0.1% cream or vehicle to each side of the face twice daily for 8 weeks. Mexameter measurements were performed along with photography at baseline, 4 weeks and 8 weeks. Adverse events were observed and recorded throughout the study.
  
  
  RESULTS
  All the patients completed the study. Mexameter measurements demonstrated that the melanin index of the treated side showed a significant decrease when compared with that of the vehicle-treated side after 4 weeks (p=0.006) and after 8 weeks (p<0.0005). All the adverse reactions were mild and transient.
  
  
  CONCLUSIONS
  4-n-butylresorcinol 0.1% cream showed rapid efficacy and it was well tolerated when used for the treatment of melasma.
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Huh
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Shin
authors.forename: Jung-Im
authors.initials: JI
authors.lastname: Na
authors.forename: Chang-Hun
authors.initials: CH
authors.lastname: Huh
authors.forename: Sang-Woong
authors.initials: SW
authors.lastname: Youn
authors.forename: Kyoung-Chan
authors.initials: KC
authors.lastname: Park