The prevalence of risk factor of post-inflammatory hyperpigmentation in Chinese patients treated with fractional resurfacing

Abstract

BACKGROUND: Fractional resurfacing is a new concept of skin rejuvenation whereby zones of micro thermal injury in the skin are generated by the use of an infra-red laser. The risk and prevalence of hyperpigmentation in dark-skinned patients have not been studied. OBJECTIVE: To assess the prevalence and risk factor of post-inflammatory hyperpigmentation associated with the use of fractional resurfacing in Chinese. METHOD: A retrospective study of 34 Chinese patients treated with fractional resurfacing for acne scarring, skin rejuvenation and pigmentation were studied. NO cooling was used. All cases had pre- and post-treatment clinical photographs taken by the Canfield CR system. 2 independent observers assessed the photographs. A prospective study using 9 different density and energy treated on the forearm of 18 volunteers. Clinical photographs and spectrophotometer reading were assessed pre- and post-treatment. RESULT: 117 treatment sessions were performed. Patients treated with high energy but low density (16 mJ, 1000 MTZ) has a lower prevalence of PIH (7% vs 11%) than those treated with a low energy but high density (8 mJ, 2000 MTZ). Prospective forearm study confirmed the importance of low density in the determination of PIH in Chinese. CONCLUSION: Cooling and reduced density are important parameters in reducing the risk of PIH in Chinese in the treatment of fractional resurfacing.