Postinflammatory hyperpigmentation: evolving combination treatment strategies.

Postinflammatory hyperpigmentation (PIH) is a common acquired excess of pigment in the epidermal and/or dermal layers of the skin. Lesions persist for extended periods if untreated, thus therapy is warranted. Topical monotherapies include the standard bleaching agent hydroquinone (HQ) as well as retinoids. Recently, several fixed-dose combination products were introduced to the armamentarium: HQ 4%-retinol 0.15% in a microsponge formulation; HQ 4%-retinol 0.3%; mequinol 2%-tretinoin (RA) 0.01%; and fluocinolone acetonide (FA) 0.01%, HQ 4%, and RA 0.05%. Recent findings have suggested that mequinol 2%-RA 0.01% solution is a promising alternative for the treatment of PIH.