Topical Isotretinoin for Melasma in Thai Patients: A Vehicle-Controlled Clinical Trial
VICHIT LEENUTAPHONG, M.D.*, APIYUT NETT AKUL, M.D.*, PAKAMASH RATTANASUWON, B.N.*
Affiliation : * Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Background : Melasma is an acquired hyperpigmentary disorder commonly seen in
Orientals. Recently it has been demonstrated that tretinoin (all-trans-retinoic acid) can produce
significant clinical improvement of melasma. However, moderate cutaneous side effects (retinoid
dermatitis) occurred in a number of patients.
Objective : To investigate the efficacy of topical 0.05 per cent isotretinoin gel (Isotrex)
in the treatment of melasma in Thai patients.
Method : Thirty patients with moderate to severe melasma entered a 40-week, ran-
domized, vehicle-controlled clinical trial in which they applied either 0.05 per cent isotretinoin
gel, or its vehicle base together with a broad spectrum sunscreen (SPF 28) daily to the entire face.
They were evaluated clinically (using Melasma Area and Severity Index), and colorimetrically
(using our Melasma Area and Melanin Index).
Results : After 40 weeks, the average MASI and MAMI scores of the isotretinoin-treated
group decreased by 68.2 per cent and 47 per cent respectively, while the corresponding control
scores declined 60 per cent and 34 per cent. There was no statistically significant difference
between the isotretinoin and vehicle groups. When the MASI and MAMI scores of each visit
were compared to their baseline data, a statistically significant reduction of the score was first
noted at weeks 4 and 12 respectively. Lightening of melasma, as determined clinically (MASI
score), correlated well with pigmentation measurements (MAMI score). Side effects were limited
to a mild transient "retinoid dermatitis" occurring in 27 per cent of isotretinoin-treated
patients.
Conclusion : Daily use of broad spectrum sunscreen has a significant lightening effect on
melasma in Thai patients. However, there was no statistically significant difference between the
isotretinoin and vehicle-treated group.
Keywords : Melasma, Treatment, Isotretinoin
