Energy-Based Devices for the Treatment of Facial Skin Conditions in Skin of Color

J Clin Aesthet Dermatol. 2024;17(6):22–32.

by Riana D. Sanyal, MD, MSc, and Sabrina G. Fabi, MD

Dr. Sanyal is with the Department of Dermatology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, California and the Metropolis Dermatology, Los Angeles, California. Dr. Fabi is with Cosmetic Laser Dermatology, San Diego, California and University of California, San Diego, California.

FUNDING: No funding was provided for this article. 

DISCLOSURES: The authors have no conflicts of interest relevant to the contents of this article. 

ABSTRACT: Background. The development of microfocused ultrasound and fractional radiofrequency-based devices has expanded the range of cosmetic treatment options for patients with skin of color. Fractional non-ablative laser treatments can also be safely performed in skin types III-VI with appropriate settings and adjunctive topical treatments.

Objective. We sought to review the available literature on the use of energy-based devices for treatment of facial skin conditions in skin types III-VI.

Methods. A PubMed search was performed on studies from 2010-2021 assessing safety and efficacy of fractional ablative and non-ablative lasers, radiofrequency, and microfocused ultrasound-based treatments for conditions such as acne scars, melasma, benign pigmented lesions, rhytids, and skin laxity in skin types III-VI.

Results. Seven randomized trials, fourteen prospective cohort studies, and six retrospective reviews were included. Combination treatment with fractional radiofrequency and non-ablative laser has demonstrated efficacy in the treatment of acne scars in skin of color with minimal adverse effects. Laser-assisted drug delivery with low-density 1927-nm thulium or diode lasers has been shown to reduce the number of treatments required for significant clearance of melasma as compared with other modalities. Microfocused ultrasound has been shown to safely treat skin laxity in skin of color.

Limitations. There is a paucity of studies which include patients with skin type VI, limiting our overall understanding of the safety of these treatments in skin of color.

Conclusion. There are numerous available studies demonstrating safety and efficacy of energy-based devices for the treatment of facial skin conditions in skin types III-VI, but the significant variation among their designs, methods of assessment, and study populations highlights the need for larger meta-analyses to further interpret their results.

Keywords: Laser, skin of color, radiofrequency microneedling, microfocused ultrasound, melasma, acne scars, skin laxity

Introduction

There is a growing demand for cosmetic procedures that are safe and effective for diverse patient populations. In 2018, African American, Hispanic, and Asian patients received 28% of cosmetic procedures performed in the United States,¹ increased from 24% in 2015.² The development of energy-based devices such as microfocused ultrasound and fractional radiofrequency,  which utilize energies that are not specifically absorbed by melanin and thus function independently of skin color, has revolutionized the landscape of non-invasive treatment options for skin laxity, acne scarring, pigmentary conditions, and rhytids in patients with darker skin types.^3,4 These devices are advantageous for patients with skin of color due to a lower risk of post-inflammatory hyperpigmentation associated with their use, as compared with ablative and non-ablative lasers. Still, laser and light-based devices are known to be highly effective for the treatment of these conditions, and recent studies have demonstrated that the use of conservative treatment settings can minimize adverse effects such as post-procedure hyper- or hypopigmentation in patients with Fitzpatrick Skin Types III to VI.^5–7 Many studies have therefore examined the delicate balance between optimizing efficacy and reducing risk of adverse effects when treating patients with skin of color. Herein, we review the literature from the past decade that has focused on patients with skin phototypes (SPT) III to VI in analyses of the safety and efficacy of energy-based devices, including ablative lasers, non-ablative lasers, fractional radiofrequency (RF), and microfocused ultrasound for treatment of acne scars and pigmentary conditions, as well as for skin tightening and rejuvenation.

Methods

This is a review of the available literature on the safety and efficacy of ablative laser, non-ablative laser, fractional RF, and microfocused ultrasound treatments for facial skin conditions in skin of color. The facial skin conditions covered in this review include acne scars, melasma, benign pigmented lesions, skin laxity, and rhytids. The PubMed database was queried for key terms including “skin of color,” “Fitzpatrick skin type,” “laser,” “radiofrequency,” “microfocused ultrasound,” “acne scars,” “melasma,” “skin rejuvenation” and “skin tightening.” Studies conducted between the years 2010 to 2021 with a focus on patients with SPT III-IV were included. Randomized trials, prospective observational cohort studies, and retrospective cohort studies were included, while individual case reports were excluded.

Results

Acne scars. Acne scars are typically treated with a multimodal approach, as different scar morphologies (e.g., icepick, boxcar, and rolling scars) respond variably to different devices and techniques.^8,9 Treating acne scars in skin of color adds a layer of complexity, as devices traditionally thought to deliver more dramatic and consistent results, such as ablative lasers, have also been associated with higher risk of post-inflammatory hyperpigmentation (PIH), hypopigmentation, or scarring in these populations.¹⁰ Four randomized rater-blinded trials, two prospective cohort studies, and three retrospective reviews of the treatment of acne scars with energy-based devices (fractional ablative and non-ablative lasers and RF microneedling) met inclusion criteria (Table 1). 

Treatment of acne scars with fractional ablative lasers: CO₂ and erbium:YAG. A split-face, randomized, rater-blinded trial of fractional 2,940nm Erbium:YAG and fractional 10,600 nm CO₂ laser for the treatment of acne scars in 24 Thai subjects with SPT IV showed that fractional Erbium:YAG provided less coagulation depth and ablation yet offered a similar clinical outcome compared with the CO₂ laser.⁷ Per blinded rater assessment, 55% of Erbium:YAG and 65% of CO₂ treated sites showed >50% improvement at the six-month follow up. Objective assessment of scar volume reduction achieved significance at 3- and 6-month follow ups (9.5-13.2% reduction), with no difference between the two laser types, and higher incidence of PIH in the CO₂ laser side (35% versus 50% lasting up to 7 weeks). Pain levels were reported to be significantly greater on the CO₂ laser side, despite equivalent numbing with topical lidocaine and prilocaine for one hour in both sides. Therefore, the authors determined Erbium:YAG to be the more favorable treatment modality for this population.

Two prospective cohort studies of fractional ablative erbium:YAG and CO₂ laser for treatment of acne scars in Indian patients with SPT III-V showed mixed results depending on scar type. A study of 25 Indian patients with Grades 2 to 4 acne scarring showed that after four monthly treatments with an Erbium:YAG fractional laser, 76% of patients were determined to have only “fair” (25-50%) improvement, while 20% showed “good” (50-75%) improvement.¹¹ A study of 60 Indian patients receiving four sessions of CO₂ laser treatment for moderate to severe acne scars showed >50% improvement of scars in 43% of patients. In both studies, rolling scars showed significantly greater improvement than icepick scars.¹² Both studies demonstrated low incidence of PIH (2% of patients receiving erbium:YAG treatment, resolving within one month, and 5% of patients receiving CO₂ treatment, resolving within 2 to 3 months). Similarly, a retrospective cohort study of 80 SPT IV-V patients receiving four treatments with fractional erbium:YAG showed >50% improvement in 46% of patients, with only one patient experiencing PIH lasting one month. Rolling and superficial boxcar scars responded favorably, while icepick scars generally responded poorly to fractional ablative laser treatment.¹³ 

Taken together, these data demonstrate that fractional ablative erbium:YAG and CO₂ lasers are both effective for the treatment of acne scars with either rolling or superficial boxcar morphologies in SPT III-V, while those patients with predominantly icepick or deep boxcar scars are unlikely to achieve significant improvement with these treatments. Results of one randomized trial indicated that the safety profile of erbium:YAG may be more favorable than that of CO₂ with regards to risk of PIH and pain, however other prospective cohort studies found an overall low risk of prolonged PIH <5% with CO₂ laser treatment.

Treatment of acne scars with non-ablative fractional lasers and radiofrequency devices. Non-ablative fractional lasers, RF devices, and combinations of these two modalities have piqued interest for treatment of acne scarring in patients with skin of color due to their  potential to minimize pain, pigmentation and scarring relative to ablative lasers. Alexis et al¹⁴ performed a randomized, blinded, split-face study of seven patients with SPT IV to VI treated with a non-ablative 1550-nm erbium-doped laser for facial acne scarring. Patients received a lower density treatment (11% coverage) to one side of the face and higher density treatment (20% coverage) to the other, with a consistent energy of 40mJ. After four treatments, there was a significant improvement in scarring noted at Week 16 and Week 24 follow ups on both sides of the face. There was no significant difference in efficacy between densities, but there was a higher rate of PIH lasting four or more weeks noted on the higher density side, and pain ratings were significantly higher for the higher density treatment despite consistent topical anesthetic (23% lidocaine and 7% tetracaine for 45 minutes) applied to both sides¹⁴ 

Mahmoud et al⁶ prospectively followed 15 patients with SPT IV to VI through five monthly treatments with an erbium-doped 1550nm fractionated laser for acne scarring, comparing the 10mJ and 40mJ treatment settings. Patients were divided into 10mJ and 40mJ treatment groups, and eight passes were performed with 17% coverage in both groups. At one-month post treatment, both groups had significant improvement per blinded investigators, six patients (40%) developed PIH lasting months, and there were no differences in these parameters between groups. However, pain levels were found to increase with higher energy and higher skin type (despite equivalent numbing with 30% lidocaine cream was applied for one hour in both groups).⁶ In summary, these studies suggest that increasing the energy or density of a fractional non-ablative laser treatment may not impact its efficacy in treating acne scars, but may result in either higher incidence of PIH or increased pain levels.   

RF technologies deliver heat to the dermis in a manner that is based on the electrical properties of the target tissue and therefore does not target specific chromophores. It stimulates collagen remodeling and neo-collagenesis at the level of the reticular dermis, but does not cause direct thermal damage to the epidermis, particularly with the use of insulated needles.¹⁵ This mechanism is thought to minimize side effects in darker skin types. A fractional RF device was tested in a prospective cohort of 31 Indian patients with SPT III-V for the treatment moderate to severe acne scarring.¹⁶ Patients received four treatments four weeks apart with needle depths customized to scar type. Eighty-sex percent of patients with severe (Grade 4) scarring showed improvement by two grades and 76 percent of patients with moderate (Grade 3) scarring improved by two grades. While boxcar and rolling scars improved more than icepick scars, all scar types showed considerable improvement. Sixteen percent of patients had transient PIH.¹⁶ 

A retrospective cohort review of the efficacy of a high-intensity focused RF device on acne scarring included 13 Black, Hispanic, East Asian, and South Asian individuals with SPT IV-VI, who received an average of 1.8 treatments.¹⁷ The mean improvement score was 3.1 representing significant clearing (50–75%), and adverse effects were limited to PIH lasting less than 1 month in one patient. 

Kwon et al¹⁸ investigated a potential synergistic effect of the combination of a non-ablative 1550-nm erbium doped laser with RF microneedling to treat acne scars in 26 Korean patients with SPT III-IV. In a split-face design with one side receiving laser alone (25-35J/cm², 4 passes, 17% coverage) and the other side receiving laser followed by MRF (1.5-2.5mm depth, 20–50 intensity, 2–3 passes) on the same day for three sessions, the combination side showed significantly superior efficacy with a short average downtime of 2.6 days. While all scar types demonstrated significant reduction with treatment, icepick scars showed a significant reduction after the second treatment with the combination regimen only. Pigmentary changes and scarring were not observed.¹⁸ 

Overall, fractional RF treatment in skin of color has been shown to be effective in treating various morphologies of acne scarring, and associated with more transient PIH (lasting less than one month) compared with both ablative and non-ablative laser technologies. Combination treatments with non-ablative lasers and RF have the potential to optimize outcomes with minimal adverse effects.

Melasma and benign pigmented lesions. Melasma is a common hyperpigmentation condition which can be triggered by sun exposure, hormonal changes, and use of certain medications.¹⁹ It is more prevalent among patients with skin of color, including Black, Hispanic, and Asian patient populations.²⁰ For instance, while the prevalence of melasma in the general population is estimated at 1%, studies, the Latin American population in the United States has an estimated prevalence of 8.2 to 8.5%, while a study on the Arab-American population in the United States reported prevalence of 13.4 to 15.5%.²¹  

Melasma is associated with high rates of recurrence: a commonly used topical treatment regimen includes topical combinations of hydroquinone, corticosteroid, and tretinoin which are associated with risk of exogenous ochronosis, thinning of the epidermis, and PIH secondary to irritation after prolonged treatment.²² Thus, patients are encouraged to take breaks with their topical treatments, and melasma is susceptible to recurrence during time off from treatment. Oral tranexamic acid at doses ranging from 500mg to 1,500mg daily, with a typical dosing of 250mg twice per day, has been shown to be a safe and effective treatment for melasma; however, it is typically used for short 8 to 12-week courses and recurrence after treatment cessation is common.²³ Laser treatments, especially in combination with topical or oral tranexamic acid, can be effective in treating melasma in patients with skin of color. Three randomized trials, two prospective cohort studies, and two retrospective studies were included in this review (Tables 2 and 3).  

Treatment of melasma with fractional non-ablative lasers. Q-switched (QS) and picosecond lasers are commonly used for removal of pigmentation, as they utilize short, intense pulses of energy which can induce rupture of pigment-containing cells while minimizing risk of injury to normal adjacent tissue.²⁴ QS and picosecond lasers may also target dermal pigment, while topical treatments do little to address this. Jang et al²⁵ studied the efficacy of the Q-switched ruby laser (QSRL) for treating dermal-type or mixed melasma in a prospective cohort of 15 Korean women with SPT III-IV. Their protocol utilized lower fluences (2-3J/cm₂) compared with prior studies that detected hyper- and hypopigmentation with QSRL at fluences of 4.5-7.5J/cm₂. After six treatments, there was a significant 30% decrease in mean Melasma Area Severity Index (MASI) score at Week 16 follow up. Of note, two patients had no change from their baseline MASI score, and two had slight worsening, but clearance followed by recurrence was not described in this study.²⁵ In contrast, a prospective study of the treatment of melasma in 27 SPT III-IV patients with 8 sessions of QS Nd:YAG laser treatment (also with low fluence, 2.6-3.6J/cm₂) showed a similar decrease in mean MASI by 44% after the last session, but reported a high rate of recurrence of 40% at 12 week posttreatment follow up.²⁶ 

Fractional picosecond lasers are advantageous in their ability to generate sub-nanosecond range pulse durations, which allow for effective destruction of pigment at lower fluences, reducing the risk of epidermal damage. For example, a prospective study of fractional 1064-nm picosecond laser treatment of melasma in 20 Chinese patients with SPT III-IV showed that after nine treatments, modified MASI scores decreased by 75 percent at six weeks and 67 percent at 12 weeks posttreatment. While two patients (10%) experienced recurrence at the 12-week follow up visit, no dyspigmentation or other significant adverse effects were noted in this study, providing evidence of the overall safety of this treatment modality for skin of color.²⁷ 

Benign pigmented lesions including lentigines, café-au-lait macules, nevus of Ota, and postinflammatory hyperpigmentation appear to respond quickly and effectively to fractional picosecond lasers, with minimal adverse effects. A prospective study of treatment with a dual wavelength picosecond laser for benign pigmented lesions (532nm) and melasma (1064nm)  in 12 SPT III-IV patients highlighted the contrast in response rates between these two conditions. The picosecond laser was most effective in treating lentigines, for which 100% of patients had excellent response (75–94% clearance) after just two treatments, while a total of 9 treatments were required for the 25 percent of melasma patients who had excellent response to achieve this outcome.²⁸   

A retrospective comparison study of the safety and efficacy of a 755-nm picosecond laser, QS Nd:YAG laser, and QS Ruby laser in treating benign pigmented lesions in 42 SPT III-VI patients demonstrated a superior safety profile of the picosecond laser treatment compared with the others.²⁹ While the mean number of treatments (4-5) and efficacy (approximately 50% pigmentary clearance) of the QS and picosecond lasers were comparable, four patients (16%) in the QS laser group with Skin Types V to VI had permanent dyspigmentation, while the PIH noted in three patients who underwent picosecond laser treatment resolved completely within three months.²⁹ 

In summary, both fractionated QS and picosecond lasers are similarly effective for the treatment of benign pigmented lesions (such as lentigines and café-au-lait macules) in skin of color, although one retrospective study demonstrated a more favorable side effect profile associated with picosecond laser. For the treatment of melasma in skin of color, a consistently high number of treatments (between 9 and 12) is required for effective clearance of melasma with fractionated QS and picosecond lasers alone in skin of color, and recurrence rates ranging from 10 to 40% have been reported. Consequently, laser assisted drug delivery and combination treatment with topical lightening agents for melasma is an ongoing area of investigation.

Laser-assisted drug delivery and combination treatments. Laser-assisted drug delivery, specifically the low-density 1927-nm thulium laser for delivery of topical tranexamic acid, may ultimately lower the number of sessions required to effectively treat melasma with fractional non-ablative lasers.³⁰ A split-face, double-blind, randomized controlled study of fractional thulium 1927-nm laser combined with topical tranexamic acid (TXA) versus placebo (moisturizer) for the treatment of melasma in 46 patients with SPT III-V.³¹ After four weekly treatments, there was a significant improvement in MASI scores for both TXA and control sides that was sustained at three and six month follow ups. Adverse effects were limited to “mild hyperpigmentation” noted in 8.6% of patients on the TXA side, and 6.5% of patients on the laser-only side. Combination therapy with the low-density fractional thulium 1927-nm laser and topical TXA has also demonstrated efficacy in the treatment of hyperpigmented scars³² and postinflammatory hyperpigmentation³³ in SPT III-V, over an average of fewer than four treatments and with no associated prolonged erythema or worsening dyspigmentation. 

A double-blind, randomized controlled trial of treatment of melasma with a 1927nm-diode laser was performed including 40 SPT III-V patients who received either 2% hydroquinone (HQ) or moisturizer during four laser treatments at two-week intervals.³⁴ While both groups achieved approximately 50-percent improvement in Mottled Pigmentation Area Severity Index (MoPASI) at 4- and 12-weeks posttreatment with no adverse effects, combination treatment with HQ was associated with a significantly higher Global Aesthetic Improvement Scale (GAIS) score at Week 12. 

Combination treatment of melasma with the 1927-nm fractional diode laser and 650mg daily oral tranexamic acid has been shown to further decrease the number of treatments required to achieve good clearance of melasma in patients with skin of color.³⁵ A retrospective review of this treatment in 31 SPT I-V patients (in which 45% were  SPT IV or V) showed that after a mean of only 2.4 laser sessions at either high or medium settings, 80.7 percent of patients had good-to-excellent clearance of their melasma when assessed with a visual analog scale at a mean follow up period of 2.9 months. There were no documented adverse effects such as prolonged dyspigmentation, prolonged erythema, or scarring, as well as no adverse effects related to oral tranexamic acid.  

A prospective study of 60 Indian patients (SPT IV-V) with melasma compared weekly treatments of QS Nd:YAG laser at low fluences (0.5-1J/cm²), versus twice daily application of 20% azelaic acid or a combination of both treatments over a 12-week period. There was a 72.8-percent decrease in mean MASI score at 12 weeks in the combination group, which was significantly greater improvement compared with either treatment alone.³⁶ No side effects were noted, however follow-up data was not included and thus recurrence rates in these patients is unknown. Of note, this combination treatment required a significantly higher number of sessions (12) for clearance of melasma as compared with laser assisted drug delivery using fractionated 1927nm lasers with topical TXA (4), which appears to be a more favorable choice of treatment for melasma in patients with skin of color.

Skin tightening with microfocused ultrasound treatment. Non-invasive skin tightening devices function to decrease skin laxity by stimulating contraction of collagen in the deeper layers of the skin, which then leads to development of new collagen as well as shrinking of high-elasticity tissues. Radiofrequency delivers heat uniformly to the deeper dermis, stimulating collagen contraction followed by remodeling, while microfocused ultrasound (MFU) therapy utilizes acoustic energy to produce small microcoagulation zones in the deeper dermis and subdermis. With both treatments, the epidermis is unaffected.^3,4 These modalities are considered safe for use in patients with skin of color as their energies are not specifically absorbed by melanin. Moreover, MFU with visualization (MFU-V) provides real-time imaging of tissue depth, which can capture anatomical variations in thickness and densities of skin and SMAS among individuals, thus increasing the accuracy of this treatment.³⁷ Four prospective studies demonstrating the efficacy of this treatment modality in skin of color were included (Table 4). 

A single treatment of MFU-V performed in a prospective study 50 adults of Indian ethnicity with mild lower face skin laxity yielded moderate (in 40% of subjects) to significant (in 60%) improvement at the six-month posttreatment visit³⁸ These results were sustained for up to one year. Side effects were transient but significant, with edema lasting up to 14 days in some individuals and 20 percent of patients reporting severe pain during the procedure. Another prospective study of MFU-V for skin tightening of the lower face in 22 Korean individuals showed similar results with improvement of the nasolabial folds in 91 percent of patients at two-month follow up; however the side effect profile differed in that pain was minimal (despite similar device settings and topical anesthetic protocol), edema lasted only 2 to 3 days, and four patients developed numbness along the mandible lasting 2 to 3 weeks which was not observed in the Indian cohort.³⁹ 

An open-label trial of 52 patients with SPT III-VI receiving MFU-V therapy for treatment of skin laxity in the face and neck provided reassuring evidence of the safety of this procedure for patients with darker SPTs,⁴⁰ as 35 percent of patients included were individuals with SPT V to VI. There were three adverse effects reported including prolonged erythema with mild scabbing, mild edema, and welts on the skin, all of which resolved within 90 days. In contrast, a safety analysis of MFU-V in 49 Chinese patients with skin types III to IV reported severe pain during 54 percent of treatments, and focal bruising lasting up to one month in 25 percent of patients. One patient had perioral numbness lasting for one month.⁴¹

Based on a limited number of open-label, non-blinded studies, MFU-V is a relatively safe treatment for skin laxity in patients with skin of color, as all reported adverse effects lasted <1 month including edema, bruising, focal numbness, and pain, while there were no reports of significant dyspigmentation with this treatment. The effectiveness of MFU-V in treating mid-to-lower face laxity was consistently demonstrated across two prospective cohort studies in Indian and Korean patient populations. It should be noted that while some studies reported significant pain as an adverse effect of MFU-V, their protocols either did not include any type of analgesia,⁴¹ or were limited to topical anesthetics only.^38,39 More recently, various approaches to providing adequate pain management during MFU have been published, which include the use of inhaled nitrous oxide and oxygen during the procedure, pre-medication with oral ibuprofen and diazepam, or regional lidocaine blocks.⁴² Implementation of these methods may decrease pain scores and improve the overall patient experience during this procedure.

Skin rejuvination with radiofrequency microneedling and fractional non-ablative laser treatment. “Skin rejuvenation” is a broad term commonly used in reference to an overall improvement in skin texture, tone, fine lines, and appearance of pores. There are two prospective studies that specifically investigate the effects of energy-based devices on skin rejuvenation in darker skin types V to VI (Table 4). One prospective cohort study of a fractional bipolar RF device with insulated tips for skin rejuvenation and acne scar treatment in 35 patients with SPT VI showed that, after three monthly sessions, there was significant improvement in their Fitzpatrick Wrinkles Classification, acne scars, and overall facial appearance at follow up compared with baseline with no adverse effects.¹⁵ The authors hypothesized that the use of RF tips with insulated coated pins confers a superior safety profile for skin of color as it reduces heating of the epidermis. A similar design was employed by Man & Goldberg in a prospective study of 15 women with SPT V-VI who received three monthly treatments with fractional bipolar RF to the full face.⁴³ Eighty-seven percent of patients showed improvement in wrinkles, texture, and fine lines by the Fitzpatrick Scale of Wrinkling and Elastosis, and no dyspigmentation was noted. 

Given the high degree of subjectivity involved in physician assessments of skin rejuvenation, studies which utilize more objective measurements of endpoints are important for validation of these results. In a prospective cohort of 31 Asian patients receiving four sessions of fractional RF treatment, Kim et al⁴⁴ performed objective biophysical measurements using a cutometer to demonstrate improvements in skin elasticity and laxity, resulting in improved appearance of pores, with efficacy comparable to that of non-ablative laser treatment.^44,45 Pain scores were low and no PIH was noted in this cohort, however scabs were observed as microcrusts which persisted for an average of 6 days.

Histologic findings in a study of skin rejuvenation with monopolar RF in 6 SPT III-IV patients provided insight into the effects of RF on a cellular level.⁴⁶ In this study, statistically significant decreases in total elastin, increases in epidermal and granular layer thickness, and increases in types I and III collagen content were detected in biopsies of facial skin obtained during the three-month posttreatment visit after 6 sessions of RF as compared with baseline.⁴⁶ These changes correlated with impressive clinical results showing 90 to 95-percent improvement in rhytids and 70 to 75- percent improvement in skin tightening at three-month follow up.⁴⁶

Recent analyses of fractional non-ablative laser treatments in skin of color populations have reported lower incidence of PIH in context of more conservative device settings. For instance, a retrospective analysis of 252 Indian patients with skin types III to IV undergoing skin rejuvenation treatment with fractional 1064-nm Q-switched Nd:YAG reported improvement in skin texture and tone over three bi-weekly sessions of treatment, with transient erythema as the only adverse effect.⁴⁷

In summary, while evidence behind the safety and efficacy of RF microneedling for skin rejuvenation in skin of color is limited to a few prospective non-blinded studies, these studies  are unique in their strong representation of patients with Type V and VI skin and are consistent in their demonstration of a favorable side effect profile. Measurements of efficacy of RF microneedling and fractional non-ablative laser treatment for skin rejuvenation are difficult to generalize across studies, as results are dependent on subjective observation of physicians or other clinical evaluators. Studies demonstrating significant histologic changes in facial collagen or improvement in biophysical measurements of skin laxity in response to RF treatment have provided more objective data in support of the efficacy of these treatments in skin of color.

Conclusion

The rapid innovation of novel light, laser, and energy-based devices over the past ten years has greatly expanded the sphere of treatment options for acne scars, pigmentary conditions, skin laxity, solar damage and rhytids for patients with skin of color. As a result, it is now more essential for physicians to optimize their treatment plan to a patient’s individual skin type and logistical needs, as we currently have ample data to consider regarding number of required treatments, downtime, adverse effect profile, and overall efficacy of these treatments in SPT III to VI, either alone or in combination with other modalities. 

There are several practical treatment considerations that can be gathered from the results of the studies included in this review. First, while fractional ablative laser technologies may be efficacious in the treatment of acne scars, a combination of fractional non-ablative lasers (such as the 1550-nm erbium-doped laser) and fractional RF may optimize outcomes for treatment of skin of color with minimal adverse effects. For treatment of melasma, which typically requires multiple sessions and is associated with high rates of recurrence, the use of the low-density 1927-nm thulium or 1927-nm diode lasers in conjunction with topical or oral tranexamic acid, or other lightening agents such as hydroquinone, may necessitate fewer treatment sessions and yield longer remission times compared with Q-switched Nd:YAG or fractional picosecond laser treatments. Microfocused ultrasound for skin tightening and fractional RF for rejuvenation appear to be safe and effective therapeutic strategies for skin of color, and most studies report no associated hypo- or hyperpigmentation. 

Our understanding of the safety and efficacy of these treatments in skin of color is limited by the paucity of studies which include or focus exclusively on SPT V to VI. Of all the studies included in this review, only one focused exclusively on patients with skin type VI. While several studies included patients with skin type VI, results were not stratified by skin type; therefore, it is difficult to draw conclusions on how certain treatments would specifically impact patients with darker SPT V and VI. 

In order to effectively compare the safety and efficacy of such different technologies in the setting of varying study designs, device settings, and patient populations, larger meta-analyses are needed to consolidate these data to ultimately aid dermatologists in making practical and individualized treatment decisions for their patients.

References

1. The American Society for Aesthetic Plastic Surgery’s Cosmetic Surgery National Data Bank: Statistics 2018. Aesthet Surg J. 2019; 39. doi:10.1093/ASJ/SJZ164
2. Cosmetic Surgery National Data Bank Statistics. Aesthet Surg J 2016; 36 Suppl 1: 1–29. doi:10.1093/ASJ/36.SUPPLEMENT_1.1
3. Fabi SG. Noninvasive skin tightening: focus on new ultrasound techniques. Clin Cosmet Investig Dermatol. 2015; 8: 47. doi:10.2147/CCID.S69118
4. Tan MG, Jo CE, Chapas A, et al. Radiofrequency microneedling: a comprehensive and critical review. Dermatol Surg. 2021; 47: 755–761. doi:10.1097/DSS.0000000000002972
5. Kaushik S, Alexis AF. Nonablative fractional laser resurfacing in skin of color: evidence-based review. J Clin Aesthet Dermatol. 2017; 10: 51–67
6. Mahmoud BH, Srivastava D, Janiga JJ, et al. Safety and efficacy of erbium-doped yttrium aluminum garnet fractionated laser for treatment of acne scars in type IV to VI skin. Dermatologic Surgery. 2010; 36: 602–609. doi:10.1111/j.1524-4725.2010.01513.x
7. Manuskiatti W, Iamphonrat T, Wanitphakdeedecha R, et al. Comparison of fractional erbium-doped yttrium aluminum garnet and carbon dioxide lasers in resurfacing of atrophic acne scars in Asians. Dermatol Surg. 2013; 39: 111–120. doi:10.1111/dsu.12030
8. Salameh F, Shumaker PR, Goodman GJ, et al. Energy-based devices for the treatment of Acne Scars: 2022 International consensus recommendations. Lasers Surg Med. 2022;54: 10–26. doi:10.1002/LSM.23484
9. Zaleski-Larsen LA, Fabi SG, McGraw T, et al. Acne scar treatment: a multimodality spproach tailored to scar type. Dermatol Surg. 2016; 42 Suppl 2: S139–S149. doi:10.1097/DSS.0000000000000746
10. Suh KS, Sung JY, Roh HJ, et al. Efficacy of the 1064-nm Q-switched Nd:YAG laser in melasma. J Dermatolog Treat. 2011; 22: 233–238. doi:10.3109/09546631003686051
11. Nirmal B, Pai SB, Sripathi H, et al. Efficacy and safety of Erbium-doped Yttrium Aluminium Garnet fractional resurfacing laser for treatment of facial acne scars. Indian J Dermatol Venereol Leprol. 2013; 79: 193–198. doi:10.4103/0378-6323.107635
12. Majid I, Imran S. Fractional CO₂ laser resurfacing as monotherapy in the treatment of atrophic facial acne scars. J Cutan Aesthet Surg. 2014; 7: 87. doi:10.4103/0974-2077.138326
13. Chathra N, Mysore V. Resurfacing of facial acne scars with a new variable-pulsed Er:YAG laser in Fitzpatrick skin types IV and V. J Cutan Aesthet Surg. 2018; 11: 20–25. doi:10.4103/JCAS.JCAS_4_18
14. Alexis AF, Coley MK, Nijhawan RI, et al. Nonablative fractional laser resurfacing for acne scarring in patients with Fitzpatrick skin phototypes IV-VI. Dermatologic Surgery. 2016; 42: 392–402. doi:10.1097/DSS.0000000000000640
15. Battle EF, Battle S. Clinical evaluation of safety and efficacy of fractional radiofrequency facial treatment of skin type VI patients. Journal of Drugs in Dermatology. 2018; 17: 1169–1172
16. Chandrashekar B, Sriram R, Mysore R, et al. Evaluation of microneedling fractional radiofrequency device for treatment of acne scars. J Cutan Aesthet Surg. 2014; 7: 93. doi:10.4103/0974-2077.138328
17. Ibrahimi OA, Stankiewicz KJ, Jalian HR, et al. High-intensity Focused Radio Frequency is safe and effective for the treatment of acne scars in skin of color. Dermatol Surg. 2021; 47: 860–861. doi:10.1097/DSS.0000000000002848
18. Kwon HH, Park HY, Choi SC, et al. Combined fractional treatment of acne scars involving non-ablative 1,550-nm erbium-glass laser and micro-needling radiofrequency: A 16-week prospective, randomized split-face study. Acta Derm Venereol. 2017; 97: 947–951. doi:10.2340/00015555-2701
19. Handel AC, Lima PB, Tonolli VM, et al. Risk factors for facial melasma in women: a case–control study. British Journal of Dermatology. 2014; 171: 588–594. doi:10.1111/BJD.13059
20. Handel AC, Miot LDB, Miot HA. Melasma: a clinical and epidemiological review. An Bras Dermatol. 2014; 89: 771. doi:10.1590/ABD1806-4841.20143063
21. Ogbechie-Godec OA, Elbuluk N. Melasma: an Up-to-Date Comprehensive Review. Dermatol Ther (Heidelb). 2017; 7: 305–318. doi:10.1007/S13555-017-0194-1
22. Austin E, Nguyen JK, Jagedo J. Topical Treatments for Melasma: A Systematic Review of Randomized Controlled Trials. J Drugs Dermatol. 2019;18.
23. Bala HR, Lee S, Wong C, et al. Oral Tranexamic Acid for the Treatment of Melasma: A Review. Dermatol Surg. 2018; 44: 814–825. doi:10.1097/DSS.0000000000001518
24. Kauvar ANB. Successful treatment of melasma using a combination of microdermabrasion and Q-switched Nd:YAG lasers. Lasers Surg Med. 2012; 44: 117–124. doi:10.1002/lsm.21156
25. Jang WS, Lee CK, Kim BJ, et al. Efficacy of 694-nm Q-switched ruby fractional laser treatment of melasma in female Korean patients. Dermatologic Surgery. 2011; 37: 1133–1140. doi:10.1111/j.1524-4725.2011.02018.x
26. Yue B, Yang Q, Xu J, et al. Efficacy and safety of fractional Q-switched 1064-nm neodymium-doped yttrium aluminum garnet laser in the treatment of melasma in Chinese patients. Lasers Med Sci. 2016; 31: 1657–1663. doi:10.1007/S10103-016-2034-4
27. Wong CSM, Chan MWM, Shek SYN, et al. Fractional 1064 nm picosecond laser in treatment of melasma and skin rejuvenation in asians, a prospective study. Lasers Surg Med. 2021; 53: 1032–1042. doi:10.1002/lsm.23382
28. Kung K yee, Shek SYN, Yeung CK, et al. Evaluation of the safety and efficacy of the dual wavelength picosecond laser for the treatment of benign pigmented lesions in Asians. Lasers Surg Med. 2019; 51: 14–22. doi:10.1002/lsm.23028
29. Levin MK, Ng E, Bae YSC, et al. Treatment of pigmentary disorders in patients with skin of color with a novel 755 nm picosecond, Q-switched ruby, and Q-switched Nd:YAG nanosecond lasers: A retrospective photographic review. Lasers Surg Med. 2016; 48: 181–187. doi:10.1002/lsm.22454
30. Wang J, Christman MP, Feng H, et al. Laser-assisted delivery of tranexamic acid for melasma: Pilot study using a novel 1927 nm fractional thulium fiber laser. J Cosmet Dermatol. 2021;20:105–109. doi:10.1111/JOCD.13817
31. Wanitphakdeedecha R, Sy-Alvarado F, Patthamalai P, et al. The efficacy in treatment of facial melasma with thulium 1927-nm fractional laser-assisted topical tranexamic acid delivery: a split-face, double-blind, randomized controlled pilot study. Lasers Med Sci. 2020; 35: 2015–2021. doi:10.1007/s10103-020-03045-8
32. Wang J, Lopez A, Geronemus RG. Safety and Effectiveness of Low-Density 1927-nm Fractional Thulium Fiber Laser for Hyperpigmented Scar Treatment in Fitzpatrick Skin Types II-V. Dermatologic Surgery. 2022; 48: 1009–1011. doi:10.1097/DSS.0000000000003523
33. Wang J, Lopez A, Geronemus RG. Safety and Effectiveness of Low-Energy, Low-Density 1927-nm Fractional Thulium Fiber Laser With Tranexamic Acid for Postinflammatory Hyperpigmentation. Dermatologic Surgery. 2022; 48: 1131–1133. doi:10.1097/DSS.0000000000003591
34. Wilson MJV, Jones IT, Bolton J, et al. The Safety and Efficacy of Treatment With a 1,927-nm Diode Laser With and Without Topical Hydroquinone for Facial Hyperpigmentation and Melasma in Darker Skin Types. Dermatol Surg. 2018; 44: 1304–1310. doi:10.1097/DSS.0000000000001521
35. Wang J, Valiga A, Geronemus RG. 1927nm Fractional Diode Laser and Oral Tranexamic Acid for Melasma: A 5.7-Year Summary on Safety and Effectiveness. Dermatologic Surgery. 2022; 48: 883–885. doi:10.1097/DSS.0000000000003492
36. Bansal C, Chauhan A, Kar H, et al. A comparison of low-fluence 1064-nm Q-switched Nd: YAG laser with topical 20% azelaic acid cream and their combination in melasma in Indian patients. J Cutan Aesthet Surg. 2012; 5: 266. doi:10.4103/0974-2077.104915
37. Park J-Y, Lin F, Suwanchinda A, et al. Customized Treatment Using Microfocused Ultrasound with Visualization for Optimized Patient Outcomes: A Review of Skin-tightening Energy Technologies and a Pan-Asian Adaptation of the Expert Panel’s Gold Standard Consensus. J Clin Aesthet Dermatol. 2021;14:E70
38. Shome D, Vadera S, Ram MS, et al. Use of Micro-focused Ultrasound for Skin Tightening of Mid and Lower Face. Plast Reconstr Surg Glob Open. 2019; 7: E2498. doi:10.1097/GOX.0000000000002498
39. Suh DH, Shin MK, Lee SJ, et al. Intense focused ultrasound tightening in asian skin: Clinical and pathologic Results: Clinical. Dermatologic Surgery. 2011; 37: 1595–1602. doi:10.1111/j.1524-4725.2011.02094.x
40. Harris MO, Sundaram HA. Safety of Microfocused Ultrasound With Visualization in Patients With Fitzpatrick Skin Phototypes III to VI. JAMA Facial Plast Surg. 2015; 17: 355–357. doi:10.1001/JAMAFACIAL.2015.0990
41. Chan NPY, Shek SYN, Yu CS, et al. Safety study of transcutaneous focused ultrasound for non-invasive skin tightening in Asians. Lasers Surg Med. 2011; 43: 366–375. doi:10.1002/lsm.21070
42. Fabi SG, Few JW, Moinuddin S. Practical Guidance for Optimizing Patient Comfort During Microfocused Ultrasound with Visualization and Improving Patient Satisfaction. Aesthet Surg J. 2020; 40: 208–216. doi:10.1093/ASJ/SJZ079
43. Man J, Goldberg DJ. Safety and efficacy of fractional bipolar radiofrequency treatment in Fitzpatrick skin types V-VI. J Cosmet Laser Ther. 2012; 14: 179–183. doi:10.3109/14764172.2012.699682
44. Kim JE, Lee HW, Kim JK, et al. Objective evaluation of the clinical efficacy of fractional radiofrequency treatment for acne scars and enlarged pores in Asian skin. Dermatologic Surgery. 2014; 40: 988–995. doi:10.1097/01.DSS.0000452625.01889.c3
45. Ong MWS, Bashir SJ. Fractional laser resurfacing for acne scars: a review. British Journal of Dermatology. 2012;166:1160–1169. doi:10.1111/J.1365-2133.2012.10870.X
46. El-Domyati M, El-Ammawi TS, Medhat W, et al. Radiofrequency facial rejuvenation: Evidence-based effect. J Am Acad Dermatol. 2011; 64: 524–535. doi:10.1016/j.jaad.2010.06.045
47. Agarwal M, Velaskar S. Laser Skin Rejuvenation With Fractional 1064 Q-switched Nd:YAG In 252 Patients: An Indian Experience. J Cosmet Dermatol. 2020; 19: 382–387. doi:10.1111/JOCD.13050