Microneedling vs. Lasers: Which is best for Acne Scarring?

Introduction

Acne affects 80% of people from ages 11-30 in the United States. 80% of those affected will have scarring.^1,2 Acne has a significant burden in society as it can cause psychosocial distress, lower self-esteem, and decreased quality of life.² Acne scarring adds to this burden by resulting in more physician visits and increased psychological distress. Pathologically, acne scarring is understood to result from an altered wound response to acne inflammation as well as faulty synthesis and degradation of collagen, histologically showing increased inflammatory cell infiltrates. Acne scars of the atrophic type are the most common type, which are further divided into icepick, boxcar, and rolling scars. Icepick scars are characterized as narrow and deep V shaped. Boxcar scars are wide, round-oval depressions and lastly, rolling scars are the widest and consist of superficial shadowing. When considering treatment for acne scarring, choosing a specific treatment out of the numerous available is challenging. This article aims to shed light on two widely used treatment options: microneedling and lasers. As they are two completely different approaches, it is important to understand their mechanisms, strengths, weaknesses, and their effects on skin of color.

Microneedling

Microneedling is a widely used procedure used for skin rejuvenation, acne scarring, androgenic alopecia, and to increase skin penetration of topical drugs.³ The procedure uses a roller or pen-like device with a 0.5 mm - 2.5 mm depth needle and creates many tiny wounds into the epidermis and dermis to promote healing, collagen production, elastin deposition, reduction in inflammatory markers, and synthesis of growth cytokines.^1,3,4 Microneedling has specifically demonstrated efficacy in the treatment of acne scarring.

There is growing evidence to suggest microneedling as an effective treatment for acne scarring. In a randomized clinical trial (RCT), 15 participants illustrated improvement at a six-month follow up in acne scarring after three microneedling treatments at two-week intervals compared to a placebo-controlled group.⁵ Severity of the scarring was scored using the quantitative Goodman and Baron scale, a scale based on type and number of scars. Severity of the scarring determined the depth of the needle roller; most patients used a 2 mm device while patients with fine scars used a 1 mm device. Another clinical study demonstrated similar visual improvement in ten patients with three months of microneedling treatment, six treatments with 1.5 mm-long needles at two-week intervals.⁶ Histologically, levels of type I, III, and VII collagen were significantly increased after microneedling treatment, examined via punch biopsy of acne scars.⁶ Thus, there is histological and clinical data to support microneedling as a viable treatment for acne scarring.

Microneedling, through the years, has also been modified and combined with other modalities leading to greater efficacy in the treatment of acne scarring. For instance, fractional radiofrequency microneedle system is a method of treating acne scars by utilizing the fractional photothermolysis technology i.e. light and heat energy. This method promotes rapid healing by utilizing both the skin-associated structure’s stem cells (hair stem cells, sebaceous gland stem cells, etc.) and epidermal stem cells. In a RCT, the fractional radiofrequency nanoneedle system illustrated a 50% or greater improvement in 15 patients of Asian descent at the six-month follow-up.⁷ In a 2016 study, microneedling combined with platelet-rich plasma (PRP) was compared to microneedling combined with distilled water.⁸ PRP contains growth factors that upregulate protein synthesis, collagen remodeling, and wound healing.³ The results found a 62.2% improvement after three treatments with PRP while the distilled water treatment showed only a 45.84% improvement.⁸ Another RCT had similar results. This study compared microneedling with PRP and microneedling with vitamin C. The results reported that 18.5% of 27 patients showed an excellent response with PRP versus 7.4% with vitamin C.³ Overall, microneedling has demonstrated great efficacy as well as histological improvement for the treatment of acne scarring.

Lasers

Lasers are another popular therapy for acne scarring. The thermal energy produced by these lasers is absorbed by the skin, resulting in extracellular matrix remodeling, collagen and elastin production, as well as pigmentation and erythema reduction.^3,9 Lasers are usually classified under two categories: ablative and non-ablative (Table 1). Ablative lasers use an intense wavelength of light superheating the skin while nonablative lasers use wavelengths from the visible or infrared range that does not destroy the epidermis. Within ablative and nonablative lasers, there are various specific versions of the laser; for example, they can be fractional or non-fractional and use cardon dioxide (CO₂) or erbium-doped ytrrium aluminum garnet (Er-YAG).⁹ The variety of lasers provides for greater precision when treating different pathologies or different types of atrophic scars.

Lasers have illustrated great efficacy in the treatment of scar-associated erythema and acne scarring. When treating scar-associated erythema, physicians often opt for the pulsed dye laser, which utilizes thermolysis to destroy the vasculature of the erythema. This laser provides light that is absorbed by oxyhemoglobin, facilitating the destruction of the vascular components of scar-associated erythema. Other lasers can also be used for scar-associated erythema such as potassium titanyl phosphate, erbium-doped fractional lasers, or intense pulsed light lasers.¹

For acne scarring, ablative and nonablative lasers are used. Traditional ablative lasers like CO₂ lasers and 2,940 nm pulsed Er:YAG lasers target the skin and promote collagen contraction, remodeling, and skin tightening. These lasers usually only require one treatment.¹ In an 18 month prospective study of 60 patients, immediate and prolonged improvement in skin tone, texture, and appearance was found with the 10,600 nm CO₂ laser.¹⁰ Other ablative lasers similar to the fractional type were created to minimize the side effects and maintain the same efficacy of ablative lasers. A study demonstrated that fractional CO₂ lasers improved moderate-to-severe acne scars by 50%.¹¹ A less destructive approach than ablative lasers are nonablative lasers.

Traditional nonablative lasers target water to induce collagen remodeling while still having some absorption by hemoglobin and melanin. These lasers deliver thermal energy to the dermis without damaging the overlying epidermis. However, a downside to these lasers is the need for multiple treatments.¹ In a study of 10 patients, a 29.4% improvement in acne scarring was found after eight treatments with a short pulsed 1,064 nm neodymium-doped yttrium aluminum garnet laser (Nd:YAG).¹² Nonablative lasers can also be fractionated to provide a less skin-destructive approach. Specifically, these lasers leave some skin unaffected to allow re-epithelialization with available intact skin, as opposed to complete ablation of intact skin in ablative lasers.¹ A large study of 87 patients found >50% improvement in acne scarring with the fractional 1,540 nm erbium-doped glass laser compared to the baseline scarring in 92% of patients after six treatments in six months.¹³ Thus, there are many different lasers that can be used for acne scarring with newer emerging lasers like the picosecond 755 nm Alexandrite laser. This laser has demonstrated plasma, collagen, and elastin formation in the epidermis and dermis.¹ Lasers are another effective resource to use against acne scarring. So how do they compare with microneedling?

Microneedling versus Lasers

How do microneedling and lasers compare in terms of efficacy, adverse effects, and the burden of treatment? (Table 2) A couple studies compared these two modalities head to head in treatment of atrophic acne scars. In a split-face RCT of 30 patients, Osman et al. found greater improvement in acne scarring with fractional Er:YAG lasers than microneedling after a three-month follow up (p<0.001). This study used the laser on one side of the face and microneedling on the other side of the face which minimized confounding variables that may occur between different individuals.¹⁴ In another RCT of 60 patients, the fractional CO₂ laser demonstrated higher therapeutic efficacy than microneedling when compared using the qualitative Goodman and Baron score (p=0.00). However, when the two modalities were compared using the quantitative grading system proposed by Goodman and Baron, no significant difference was found (p=0.106). Rather than being a split-face study, this study had 3 different groups, where 20 patients were treated with microneedling, 20 with the fractional CO₂ laser, and 20 with PRP.² While these studies also utilized different forms of laser treatment, results from both studies favored lasers over microneedling. In addition to these studies, a trial comparing nonablative fractional erbium doped 1,340 nm laser and microneedling demonstrated no increased difference in value between the two modalities, suggesting that certain lasers may be more efficacious than others.¹⁵ Now that we’ve reviewed the current data efficacy, how do lasers and microneedling compare in terms of adverse effects?

When considering side effects, microneedling seems to have less severe adverse events compared to lasers. For example, microneedling is mostly associated with post-treatment erythema, pain, edema, postinflammatory hyperpigmentation, and lymphadenopathy. Less commonly, microneedling can also cause acne flare-ups bleeding, milia, bruising, scabbing, hematomas, flushing, and oozing. Some of these side effects are shared with nonablative fractional lasers such as postinflammatory hyperpigmentation, bruising, and pustular folliculitis.⁴ Although a long list of side effects, these are less severe than the adverse events associated with lasers. For example, lasers may cause greater pain and longer recovery time. Traditional ablative lasers are notably more uncomfortable than nonablative lasers as they can cause dyspigmentation, infections with prolonged healing, and scarring. When traditional ablative laser therapy is utilized, preoperative prophylaxis with antivirals should be considered given risk of herpes virus infection or re-infection post-therapy.¹ To minimize some of these side effects, fractional therapy is utilized as erythema and postinflammatory hyperpigmentation are the only notable side effects. Nonablative therapies reduce these side effects even more.¹ Using lower power settings over multiple treatments may help minimize the risk of side effects.

Aftercare treatment is now increasingly studied to limit the adverse events involved with ablative lasers and microneedling. Specifically, in a RCT of 40 patients testing the effect of topical clobetasol propionate 0.05% ointment after fractional CO₂ laser compared to petrolatum jelly on different sides of the face, there was increased incidence of post-inflammatory hyperpigmentation in the petrolatum group (75%) compared to the topical corticosteroid group (40%, p <0.001). The post-inflammatory hyperpigmentation on the petrolatum group was also noted to be higher in intensity.¹⁶ Further research is required regarding the application of topical corticosteroids after microneedling, but the same principle may be applied to microneedling.

Another important aspect of microneedling and lasers is the burden of treatment. Many of the therapies with safer profiles including microneedling and nonablative fractional lasers require multiple treatment sessions to achieve optimal therapeutic efficacy. This results in an increased economic and physical burden to the patient. Additionally, when microneedling and fractional Er:YAG lasers were compared, microneedling had a downtime of 1.47 ± 0.57 days compared to 5.07 ± 0.69 days of fractional Er:YAG lasers.¹⁴ Increased recovery time from therapy can be frustrating to the patient as many wish for quick results. Efficacy, adverse effects, and burden of these treatment strategies play a role in considering which therapy to use for a patient.

Microneedling and Lasers in Skin of Color

Microneedling and lasers, although effective, are associated with adverse effects more prevalent in patients with skin of color. These complications can include post-inflammatory hyperpigmentation, hypopigmentation, infection, milia, and scarring.¹⁷ Microneedling has a lower risk of infection and scarring, as it partially keeps the epidermis intact. Nonablative and fractional lasers also maintain some epidermis intact, but the process of thermolysis increases the risk of dyspigmentation. The absorption of the specific laser wavelengths by chromophores in the skin can cause an increased effect on pigmentation.¹⁷ In a RCT comparing the safety profile of microneedling in patients with varying Fitzpatrick skin types, dyspigmentation was not seen at a one year follow up after microneedling treatment for acne scars.¹⁸ Compared to microneedling, lasers have a higher frequency and wider range of complications. Specifically, individuals with darker skin are at higher risk for complications such as dyspigmentation from lasers. Er:YAG lasers and nonablative fractional lasers like 1540 nm, rather than CO₂ lasers, are recommended for skin of color given their lower risk of thermal injury and lower risk of hyperpigmentation and hypopigmentation.^9,19 However, no randomized studies have compared nonablative fractional lasers with microneedling in skin of color. Currently, there is an interventional clinical trial being conducted that compares the fractionated 1,540 nm nonablative laser with microneedling for the treatment of atrophic acne scarring in skin of color.²⁰ Thus, when considering treatment in higher Fitzpatrick skin types, further research is needed to determine whether microneedling or laser is the better treatment modality.

Conclusion

Acne scar treatment is becoming routine in the management of acne. The psychological effects that acne scarring can have on a patient is one of the many reasons why patients may seek treatment. The treatment for acne scarring continues to expand with additions to microneedling and changes to laser strategies. To choose the best treatment modality, efficacy, adverse effects, and burden of treatment should be considered. Laser therapy may have superior efficacy data compared to microneedling. However, lasers may be associated with increased adverse events or longer down time which may put a strain on patient satisfaction. Therefore, the goals of a patient must be considered when recommending a treatment strategy for acne scarring. A patient who wants the best results may want to use the traditional ablative laser while a patient who prefers minimal adverse events and quick recovery time may choose microneedling. This article summarizes the various aspects of microneedling and lasers that patients and physicians may consider when treating acne scars.

Practical Tips

• Acne scarring may not be completely cured, but improvements can be made. Establishing expectations is critical
• Understanding the type of acne scars can help guide appropriate treatment strategy
• Individual’s need, tolerance, and goals should be considered when choosing a treatment option
• While microneedling and lasers are both efficacious, current data suggest that lasers may provide greater improvement
• Microneedling may be a better option for skin of color patients as there are fewer occurrences of post-inflammatory dyspigmentation