The role of topical retinoids in the treatment of pigmentary disorders: an evidence-based review.

Topical retinoids have been used in the treatment of pigmentary disorders such as melasma, actinic lentigines, and postinflammatory hyperpigmentation. This article evaluates the clinical efficacy and tolerability of retinoid treatment for pigmentary disorders through an evidence-based approach. We searched the MEDLINE and The Cochrane Library databases using the keywords 'retinoid' combined with 'melasma,' 'lentigines,' or 'postinflammatory hyperpigmentation.' For each study, the methodology and outcomes were assessed according to specific criteria. There is fair evidence to support the use of topical tretinoin as a monotherapy in the treatment of melasma as well as in the treatment of lentigines (grade B). Adverse effects of topical retinoids are quite frequent, and include local skin irritation, erythema, and peeling, and their severity is mild to moderate. There is evidence to support the use of topical tretinoin in a fixed, triple-combination therapy (hydroquinone 4%/tretinoin 0.05%/fluocinolone acetonide 0.01%) for the treatment of melasma (grade B). There is poor evidence (grade C) to support the use of combination formulations for the treatment of lentigines, and large, randomized, double-blind, controlled trials are needed to further evaluate their use for this indication. In conclusion, there is evidence to support the use of topical retinoids as monotherapy or in combination with other topical agents in the treatment of pigmentary disorders.