A Retrospective Chart Review to Assess the Safety of Nonablative Fractional Laser Resurfacing in Fitzpatrick Skin Types IV to VI

The use of 1,550 nm erbiumdoped fractional nonablative laser (Fraxel Re:Store SR 1550; Solta Medical, Hayword, CA) has been shown to be an effective tool for skin resurfacing and rejuvenation that is associated with fewer adverse events than traditional resurfacing lasers.^1,2

Since melanin is not targeted by the wavelength of the nonablative fractional laser, this resurfacing method is suitable for use in darker skin types (Fitzpatrick skin phototypes [SPT] IV-VI). However, the potential for treatment-associated postinflammatory hyperpigmentation (PIH) in darker skin types exists and should be accounted for by selecting appropriate laser parameters.^3,4

Previous studies have reported favorable outcomes along with low risk for posttreatment side effects with nonablative fractional lasers. Posttreatment side effects have typically been limited to transient erythema, edema, skin flaking, and acneiform eruption, with a low reported incidence of treatment-associated PIH.^2,5,6 The short-term side effects of edema, erythema, and flaking are more commonly associated with the use of higher densities.⁷ Use of higher density levels more commonly elicits symptoms of edema and PIH when compared to higher energy levels.⁷ There is an increased potential for treatment-associated PIH in darker skin types, and this is dependent on the laser parameters selected.^4-6,8,9 A retrospective study of Chinese patients undergoing resurfacing with 1,540 nm erbiumdoped fractional nonablative laser treatment demonstrated a greater risk for PIH in patients treated with high-density and low-energy parameters compared with patients treated with low-density and high-energy laser parameters (12.4% vs overall PIH rate of 7.1%).⁴ Inadequate epidermal cooling was also associated with an increased risk for PIH in darker skin types.^4,8 Bulk heating with repeated passes, especially when treating small anatomical sites, has been cited as a potential source of treatment-associated PIH, and appropriate cooling must be employed during laser resurfacing to avoid such complications.^1,4,8 Numerous studies concur that lower treatment density parameters and adjunctive cooling with fractional resurfacing be implemented, especially in darker skin types, in order to reduce the risk of PIH.^1,4,8

This study was approved by the Institutional Review Board at St. Luke’s-Roosevelt Hospital Center (Study number: 11-060X). A retrospective chart review was performed by the principal investigator (A.F.A.) during the study period from January 1, 2008, to October 30, 2011. Data were obtained from patient charts and the clinic laser logbook from St. Luke’s-Roosevelt Hospital Center Dermatology Clinics. All patient-protected health information was deidentified. Inclusion criteria for the study were SPT IV to VI, documentation of laser parameters used for each