A small open-label study of a 2% 4-hydroxyanisole and 0.01% tretinoin solution for the treatment of post-inflammatory hyperpigmentation

Abstract

Post-inflammatory hyperpigmentation (PIH) is a frequent sequel to inflammatory eruptions in the skin. PIH is particularly common in dark complected individuals with a relatively higher level of melanin production whose melanocytes overreact to cutaneous injury. PIH may persist for months to years after resolution of the initial lesion and is, to most patients, of great concern. Topical hydroquinone has been a mainstay of therapy for PIH, however, in many hyperpigmentation disorders, combination products or treatments appear to be more useful than single agents. Some studies suggest that prolonged use of hydroquinone may result in the development of exogenous ochronosis. This poster will present the results of a small study utilizing a dual agent topical solution containing 2% 4-hydroxyanisole and 0.01% tretinoin in patients with PIH from various skin disorders and conditions, including acne, burn scars, post-electrodessication, and others. Efficacy evaluations were made by means of photography and mexameter reading to assess hyperpigmented macules and safety parameters were noted. Animal studies have shown this combination to be effective in lightening skin without causing irreversible depigmentation and with minimal local irritation. 4-HA has no known cytotoxicity to human melanocytes