Advanced Fractional CO₂ Laser Treatment for Steroid-Induced Atrophy Scars: Clinical Outcomes

Introduction

Steroid-induced atrophic scars are a significant dermatological concern, often resulting from prolonged or high-potency corticosteroid use. These scars are characterized by epidermal and dermal thinning, leading to skin depression, telangiectasia, and increased fragility, which can be both aesthetically and functionally distressing for patients. The underlying mechanism involves the progressive degradation of the dermal extracellular matrix (ECM) due to suppressed fibroblast and keratinocyte activity, inhibited collagen synthesis, and disrupted elastin homeostasis [1–3].

Traditional treatment modalities, including topical therapies, microneedling, and dermal fillers, have shown variable success in improving skin texture and thickness. Effective therapeutic approaches should aim at restoring dermal architecture, by promoting ECM remodeling, fibroblast activation and the promotion of collagen and elastin production, rather than solely targeting dermal volume augmentation.

In this context, fractional CO2 laser represents a promising therapeutic strategy. As a minimally invasive technique for skin resurfacing and collagen remodeling, its delivery of controlled thermal injury stimulates neocollagenesis and epidermal regeneration, suggesting a potentially superior approach for the management of atrophic scars.

Here, we present a case of steroid-induced atrophic scarring successfully treated with a dual-session fractional CO2 laser protocol, demonstrating its efficacy in restoring dermal thickness, enhancing skin texture, and improving overall appearance.

Case Report

PATIENT INFORMATION:

A 32-year-old woman presented with a single atrophic scar on her cheek. The scar resulted from an intralesional corticosteroid injection administered to treat an inflamed sebaceous cyst. The SIAS was approximately 1 month old. The patient expressed dissatisfaction with previous treatments, including topical therapies and chemical peels. She had no significant medical history, comorbidities, or use of medications.

At the initial visit, the patient presented with a well-defined atrophic scar on the cheek, with sharp margins and a pinker, hyperpigmented color compared to the surrounding skin. The surface appeared thin and slightly wrinkled upon palpation, with a level of pliability indicating contracture. There were no signs of active inflammation, but the patient reported mild hypoesthesia in the area. The lesion had developed gradually approximately 1 month before the clinical consultation. No signs of infection or ulceration were observed.

During the diagnostic process, other possible causes of skin atrophy were considered. Autoimmune-related cutaneous atrophy (dermatomyositis or lupus erythematosus) was ruled out based on the lack of systemic manifestations (muscle weakness, joint pain, photosensitivity, characteristic rashes) and a negative medical history for autoimmune disorders. Similarly, atrophoderma of Pasini and Pierini and lipoatrophic panniculitis were excluded based on their distinct clinical and evolutionary patterns. The diagnosis of steroid-induced atrophy was confirmed based on the patient’s clinical history, the localized distribution of the lesion, and the clear temporal association with intralesional corticosteroid administration.

PREPARATION PRIOR TO LASER THERAPY:

In May 2024, the patient underwent preparatory treatment to enhance the skin’s response to laser therapy. This involved the placement of mono threads (296×38 mm, 16.0 G/60 mm) using a mesh technique with a total of 10 threads. Additionally, a bolus of dimethylaminoethanol (DMEA) skin booster was injected intralesionally at the site of thread insertion. Mono threads and DMEA skin booster were used to stimulate collagen and elastin production prior to laser therapy, ensuring enhanced dermal remodeling and optimizing laser treatment efficacy.

LASER TREATMENT:

The patient underwent 2 sessions of fractional laser treatment using a 10600 nm CO₂ laser (Youlaser, Quanta System SpA, Samarate - Italy). The sessions were spaced approximately 4 months apart, with the first session performed in June 2024 and the second in October 2024.

The selection of laser parameters was based on established principles of fractional CO₂ laser therapy for atrophic scar remodeling. The initial settings were chosen to balance efficacy and safety, ensuring sufficient dermal penetration while minimizing the risk of post-inflammatory hyperpigmentation or prolonged erythema, particularly given the facial location of the lesion.

For the first session, the power was set at 30 W, with a pulse duration of 0.50 ms and a fluence of 15 mJ/dot. The treatment was performed using a square-shaped grid measuring 18×18 mm dimensions with a density of 100 dot per cm² (CD). The Adjacent Fill Mode was utilized, and the laser was applied in 3 passes over the affected area. These settings were selected to deliver controlled thermal injury to stimulate neocollagenesis while preserving surrounding tissue to facilitate rapid healing. To ensure patient comfort, a topical galenic anesthetic cream (lidocaine 5% w/w and prilocaine 5% w/w) was applied 30 minutes before the procedure.

For the second session, the laser settings were partially adjusted to enhance treatment precision and efficacy. While the power, pulse duration, and fluence remained unchanged, the density was increased to 175 dots/cm2, and the Spread Half Fill Mode was used instead of Adjacent Fill Mode. The decision to increase density was made to intensify collagen remodeling in response to the moderate residual atrophy observed after the first session, aiming to achieve greater tissue contraction and dermal thickening. Spread Half Fill Mode was selected to ensure uniform energy distribution while reducing the risk of thermal buildup that could lead to excessive erythema. Similar to the first session, 3 passes were performed over the scarred area. Following the laser treatment, a bolus of 2.5 mL of DMEA skin booster was injected intralesionally into the scar to further stimulate dermal remodeling and enhance the results. Treatment details are summarized in Table 1.

POST-TREATMENT CARE:

After each session, the patient was advised to follow a strict skincare regimen, including the use of a gentle cleanser, emollients, and broad-spectrum sunscreen. This post-treatment care protocol was aimed at protecting the treated area, minimizing potential adverse effects, and optimizing the healing process.

OUTCOME AND CLINICAL OBSERVATIONS:

Follow-up was completed 2 weeks after the second laser session. Clinical observations revealed a significant improvement in the scar’s overall appearance, with a noticeable reduction in depth and a smoother skin texture (Figure 1).

Following the first session, the appearance of the scar showed noticeable improvement, quantified as a 60% reduction in severity based on the physician’s clinical evaluation. The treatment was well-tolerated, with minimal downtime, as erythema resolved within 1–2 days. After the second session, the results were even more pronounced. There was a marked improvement in both the depth and texture of the scar, quantified by physician as near-complete, with no adverse effects such as post-inflammatory hyperpigmentation or scarring reported. The Vancouver Scar Scale (VSS) was utilized for objective clinical evaluation at baseline and post-treatment. This scale, which assesses pigmentation (0–2), vascularity (0–3), pliability (0–5), and height (0–3), was implemented to quantify scar improvement. The baseline VSS score was 9 out of a maximum of 13. Following each laser session, a consistent reduction was recorded, culminating in a score of 5/13 after the first session and 2/13 at the final follow-up (Table 2).

The patient expressed a high degree of satisfaction with the treatment outcomes. She described a visible enhancement in her scar’s appearance, which contributed to a significant boost in her confidence and overall quality of life.

Discussion

Corticosteroids, well known for their potent anti-inflammatory and immunosuppressive properties, are widely used in clinical practice across a spectrum of disorders, ranging from localized skin conditions to systemic autoimmune diseases. Intralesional corticosteroids, often employed when topical therapies prove insufficient, yield impressive therapeutic results but are not without adverse effects.

Steroid-induced atrophic scars (SIAS) are a well-recognized complication of intralesional corticosteroid therapy, characterized by thinning of the dermis and epidermis, reduced fibroblast activity, and degeneration of collagen and elastin networks. Histopathological findings reveal epidermal atrophy, a flattened dermoepidermal junction, and involution of subcutaneous fat lobules [4]. Mechanistically, corticosteroid-induced atrophy is linked to vasoconstriction and crystal deposition, leading to localized tissue hypoxia and impaired extracellular matrix turnover. These changes manifest clinically as visible depressions and dyspigmentation, which can significantly impact patient satisfaction and quality of life.

Management of steroid-induced atrophy poses a therapeutic challenge. Various corrective approaches have been explored, including fat grafting, hyaluronic acid fillers, and intralesional saline injections [5]. Fat grafting, though durable, is expensive, invasive and technically demanding, with variable outcomes due to factors like vascularization. HA fillers offer immediate correction but are temporary, requiring repeated sessions, and have limited efficacy in dermal remodeling, with potential complications such as nodule formation and Tyndall effect, particularly in delicate facial areas [6,7]. Intralesional saline injection, on the other hand, presents a cost-effective, minimally invasive alternative. This method is hypothesized to resuspend steroid crystals, facilitating their clearance by macrophages and promoting tissue recovery [8]. Although promising, no standardized protocol exists for saline injections regarding dosage, frequency, or total number of sessions.

This case report demonstrates the successful treatment of a steroid-induced atrophic scar using a combined approach of mono threads, DMEA skin booster, and fractional CO2 laser therapy.

The choice of fractional CO2 laser therapy was based on its well-documented efficacy in stimulating collagen remodeling and improving atrophic skin conditions. The mechanism involves fractional photothermolysis [9]: utilizing a 10,600 nm wavelength, the laser penetrates 2–4 mm into the dermis, creating microscopic thermal zones (MTZs) while preserving surrounding tissue for rapid recovery. This controlled thermal damage, facilitated by the high absorption of the laser wavelength by water in the skin, eliminates fragmented collagen and triggers a robust wound-healing response through the deposition of new collagen, effectively ‘refilling’ the atrophic scar tissue [10].

Fractional CO2 laser therapy demonstrates consistent efficacy in atrophic scar treatment, reshaping skin contours and refining texture [11]. Comparative studies, notably the meta-analysis by Liu and colleagues, have further substantiated its superiority over Er: YAG fractional laser in terms of efficacy and reduced downtime, despite a noted increase in patient discomfort and erythema duration [12]. The versatility of fractional CO2 extends beyond acne scars; studies show how this approach improves the texture and minimizes the visibility of striae distensae (stretch marks) by promoting new collagen growth and restructuring the skin’s deeper layers [13]. Gu et al highlighted the critical role of early intervention, showing that treatment within 6 months of scar formation yields significantly better outcomes for linear atrophic scars [14]. In a study involving 100 patients with post-burn and post-traumatic scars, Keen and colleagues reported excellent results in 53.75% of cases, demonstrating the laser’s effectiveness across diverse scar types with minimal adverse effects [15]. This study also emphasized the necessity of tailoring treatment approaches to individual scar characteristics and patient needs, as well as the potential benefits of combination therapies for enhanced outcomes. Furthermore, research by Ozog et al has shown that fractional CO2 can significantly improve mature burn scar appearance, with collagen remodeling resembling that of non-wounded skin, evidenced by increased type III and decreased type I collagen [16]. Even in specific conditions like atrophic leishmaniasis scars, AlGhamdi and Khurrum reported a median improvement score of 18 out of 20, demonstrating the safety and efficacy of CO2 laser in diverse populations and scar types [17]. Notably, a single case report by Kineston et al found that fractional CO2 laser treatment may offer potential benefits in morphea contractures, demonstrating immediate and long-term improvements in joint mobility [18]. This suggests a possible therapeutic role for CO2 laser as an adjunct to traditional therapies.

In this case report, a preparatory phase incorporating mono polydioxanone (PDO) threads and a dimethylaminoethanol (DMEA) skin booster was implemented to optimize treatment outcomes. Mono PDO threads were strategically inserted into the dermis to provide immediate mechanical support, physically elevating depressed scars and thus reducing the required depth of laser energy penetration. This elevation facilitated a more focused and efficient delivery of laser energy to the targeted scar tissue. Furthermore, the threads induced a controlled micro-injury, stimulating fibroblast activity and subsequent neocollagenesis, thereby enhancing skin texture and elasticity. This process initiated a synergistic healing response that complemented the laser’s own wound-healing mechanisms, fostering more rapid and robust scar remodeling. Concurrently, a DMEA skin booster was administered to improve overall skin quality and cellular function. DMEA, a precursor to acetylcholine, enhanced skin hydration, elasticity, and cellular responsiveness to laser stimulation. Its antioxidant and anti-inflammatory properties further minimized post-laser inflammation and promoted smoother recovery. The combined application of mono PDO threads and DMEA skin booster effectively primed the skin, creating an optimized tissue environment for laser therapy. This synergistic approach maximized the laser’s efficacy in remodeling the atrophic scar, leading to more significant and enduring improvements in skin appearance.

The decision to employ a medium fluence, low-density approach was driven by the need to balance efficacy and safety. A medium fluence (15 mJ/dot) was chosen to achieve sufficient thermal injury for collagen remodeling while minimizing risks of excessive epidermal damage, prolonged erythema, and PIH, particularly given the facial location of the lesion. The initial low-density setting (100 dots/cm2) ensured a controlled treatment effect with faster recovery.

After assessing the patient’s response to the first session, where a 60% improvement was observed without adverse effects, a higher density (175 dots/cm2) was selected for the second session to enhance tissue remodeling while still maintaining a safe thermal profile. The switch from Adjacent Fill Mode to Spread Half Fill Mode was made to optimize uniform energy distribution, reducing the risk of localized overheating.

This approach minimized downtime, with erythema resolving within 1–2 days and no adverse effects, including PIH, reported. The results of this case demonstrate that a carefully customized, medium fluence, low-density fractional CO2 laser approach can provide significant clinical improvement with minimal downtime and a favorable safety profile. This aligns with the broader capabilities of the same laser system, which has demonstrated effectiveness in treating atrophic acne scars [19], highlighting the CO2 fractional laser’s potent combination of efficacy, safety, and patient satisfaction across diverse dermatological conditions. Building upon this foundation, the Youlaser laser system’s versatility and efficacy have been extensively documented in literature for a wide range of applications. In skin rejuvenation, it enhances skin texture by reducing fine wrinkle depth and improves skin tone by diminishing melanin accumulation [20]. Furthermore, its ability to stimulate neocollagenesis has proven beneficial in addressing vaginal atrophy in menopausal women, leading to increased elasticity and hydration of the vaginal mucosa [21,22]. This broad spectrum of applications underscores the Youlaser system’s adaptability and reliability in various dermatological treatments, reinforcing its suitability for the treatment of steroid-induced atrophic scars.

To determine if CO2 laser therapy for SIAS treatment had been previously investigated or documented in dermatological publications, we performed a comprehensive literature search in PubMed and Google Scholar. The search terms used were: “fractional CO2 laser”, “steroid-induced atrophic scars” and related synonyms. We found no studies specifically addressing the efficacy of fractional CO2 laser therapy for SIAS treatment. This highlights the novelty and significance of the findings presented in this case report, offering a potential avenue for effective management of SIAS through fractional CO2 laser intervention.

It is noteworthy that while our report presents a novel application of fractional CO2 laser for SIAS, an alternative laser intervention has been previously investigated. Mansouri et al. (2015) evaluated the efficacy of 585 nm pulsed dye laser therapy for steroid-induced atrophic changes, documenting variable therapeutic success and significant challenges with patient adherence. Their cohort study reported that only 5 of 15 enrolled patients completed the treatment protocol. Notably, both patients presenting with facial atrophic scars withdrew from the study due to unsatisfactory clinical outcomes after one and 9 treatment sessions, respectively[23]. These suboptimal results may be attributed to the inherent limitations of 585 nm pulsed dye lasers, which primarily target vascular components, limiting their ability to induce substantial dermal remodeling, which is crucial for addressing atrophic scars. Unlike pulsed dye lasers, fractional CO2 laser therapy directly stimulates collagen synthesis and dermal reorganization, potentially offering a more comprehensive approach to treating the structural deficits characteristic of SIAS.

The approach described in this study also presents several advantages over traditional alternatives like fat grafting, HA fillers, and saline injections: it addresses the underlying dermal atrophy rather than merely restoring volume; it is minimally invasive with shorter downtime (1–2 days of erythema) compared to surgical fat grafting; and unlike HA fillers, it induces long-term tissue remodeling, reducing the need for frequent retreatments. Additionally, treatment parameters can be customized based on scar severity, enabling tailored therapeutic strategies for different clinical presentations.

Although fractional CO2 laser therapy presents a promising avenue for treating steroid-induced atrophic scars, it is crucial to acknowledge the potential risks and limitations associated with this treatment. Notably, post-inflammatory hyperpigmentation poses a significant concern, particularly in patients with darker skin tones (Fitzpatrick skin types IV–VI). This risk arises from excessive melanocyte activation following thermal injury, leading to persistent hyperpigmented macules. To mitigate this, practitioners must employ lower fluence and density settings, longer pulse durations, and emphasize strict photoprotection. Additionally, other potential side effects, such as erythema, edema, and transient crusting, should be discussed, although these are typically mild and resolve quickly. Another consideration is the need for multiple treatment sessions to achieve optimal results. While some improvement was observed after a single session in this case, the most significant results were obtained after the second session. This suggests that fractional CO2 laser therapy for SIAS may require multiple treatments. Despite these limitations, the tailored approach demonstrated in the case, using medium fluence and low-density settings, effectively minimized downtime and avoided PIH, showcasing the potential for customized treatment protocols. However, it is important to note that this study, while promising, has limitations, including the absence of clinical and laboratory evaluations, histological assessments, and a limited follow-up period. To validate the efficacy and reproducibility of our dual-session protocol, future clinical trials with larger sample sizes are crucial. These studies should prioritize investigating the long-term outcomes of fractional CO2 laser therapy for SIAS, including the durability of improvements and the potential need for maintenance sessions. Comparative analyses against alternative treatments, such as hyaluronic acid fillers, fat grafting, and intralesional saline injections, are also necessary to determine relative efficacy and patient satisfaction. Optimizing laser parameters for diverse patient populations, especially those with darker skin tones, is essential to minimize PIH risks while maintaining treatment effectiveness[24]. Moreover, histological and imaging-based studies are needed to further elucidate the mechanisms of collagen remodeling and dermal regeneration following fractional CO2 laser therapy. Finally, developing standardized treatment protocols, encompassing optimal session numbers, treatment intervals, and post-procedural care, is vital for enhancing patient outcomes. By addressing these research gaps, future investigations can solidify fractional CO2 laser therapy as a standardized, evidence-based treatment for steroid-induced atrophic scars, ultimately expanding and improving therapeutic options for affected individuals.

Conclusions

This case demonstrates the promising efficacy and safety of fractional CO2 laser therapy for managing steroid-induced atrophic scars. While a two-session protocol with a four-month interval achieved significant clinical improvement, larger, controlled studies are essential to validate these findings and to determine the ideal treatment regimen, including the optimal number of sessions and follow-up duration.