Adverse Events of Nonablative Lasers and Energy-Based Therapies in Subjects with Fitzpatrick Skin Phototypes IV to VI: A Systematic Review and Meta-Analysis

Background Although there is an abundance of literature on nonablative laser and energy-based therapies for the management of skin conditions, adverse events are inconsistently addressed and range widely across studies. Fitzpatrick skin phototypes (SPTs) IV to VI are believed to be at higher risk. Objectives The aim of this study was to determine the types and rates of adverse events in nonablative laser and energy-based therapies among patients with SPTs IV to VI. Methods Articles addressing nonablative laser and energy-based therapies for skin rejuvenation and acne scarring in patients with SPTs IV to VI that provided data on adverse events were included. The pooled prevalence of each adverse event was calculated. To determine whether age, treatment indication, SPT, and device type influenced incidence, subgroup and meta-regression analyses were performed. Heterogeneity was evaluated with the I2 statistic. Results Forty-three studies were included in the meta-analysis. The sample size was 1654, and the median age of subjects was 39.4 years. The most common adverse events were postinflammatory hyperpigmentation (PIH) (rate, 8.1%) and prolonged erythema (rate, 0.6%). The rate of PIH was significantly higher for diode and erbium-doped lasers compared with intense pulsed light and radiofrequency. PIH correlated positively with SPT, laser density, and total energy delivered. Conclusions Although the overall rate of adverse events in nonablative laser and energy-based therapies for SPTs IV to VI is low, the incidence of PIH is not insignificant. Certain lasers, such as diode, Q-switched Nd:YAG, and erbium-doped lasers, tend to have higher rates of PIH, whereas intense pulsed light and radiofrequency have minimal risk. Higher SPTs and higher energy deliverance correlate positively with the incidence of PIH. Level of Evidence: 4

1927 nm Thulium Laser Successfully Treats PostInflammatory Hyperpigmentation in Skin of Color

Background. Treatment of postinflammatory hyperpigmentation (PIH) in patients with dark skin is challenging as the treatment itself might provoke paradoxical PIH. Only few studies examined the safety and efficacy of nonablative laser treatment in these patients. The objective was to examine efficacy and safety of nonablative 1927 nm wavelength laser followed by bleaching creams in the treatment of PIH. Methods. It was a prospective interventional pilot study that was conducted during 2019. All patients were of Fitzpatrick skin type IV who had unsatisfactory response to topical bleaching creams used for at least three months. Patients received one to four sessions of laser treatment (6 weeks apart) followed by topical hydroquinone 4% cream twice daily for 6 weeks. Improvement was assessed by two blinded independent dermatologist evaluators. Results. A total of nine patients were enrolled and the outcome could not be assessed in one patient who was lost for follow-up. The affected sites were the abdomen, face, and other body parts. Three of the eight evaluated patients had excellent response (37.5%), four had satisfactory response (50.0%), and one had nonsatisfactory response (12.5%). The downtime was manifested as edema and erythema that disappeared after 5 to 7 days. Improvement was more evident in first session and it declined in subsequent sessions. None of the patients had paradoxical pigmentation after treatment. Conclusions. Low energy low density nonablative fractional 1927 nm wavelength laser treatment followed by topical hydroquinone 4% cream for 6 weeks is a safe and effective modality for improving PIH in patients with darker skin types.