Efficacy and Safety of Fractional Carbon Dioxide (CO2) Laser in Benign Skin Lesions.

Benign skin lesions are non-cancerous growths that may be self-reported by patients or discovered during routine dermatological examination.

 

These lesions can accumulate over a lifetime and, though medically innocuous, often cause significant cosmetic disfigurement and psychological distress.

 

Traditional management options include cryotherapy, electrocautery, radiofrequency ablation (RFA), and surgical excision. Over the past decade, laser technology has transformed dermatological practice.

 

The carbon dioxide (CO₂) laser, operating at 10,600 nm, is considered the gold standard among ablative lasers.

 

It employs selective photothermolysis to target water-containing tissue with controlled vaporization, providing a bloodless field, minimal thermal spread, reduced patient discomfort, and rapid recovery.

 

Fractional delivery further improves outcomes by limiting thermal injury to fractionated microthermal zones, leaving surrounding tissue intact and accelerating healing. Despite widespread use, systematic safety and efficacy data for Indian skin types (Fitzpatrick III–V) remain sparse. This study addresses that gap.

 

Objectives

1.       To evaluate the efficacy of fractional CO₂ laser ablation in the treatment of various benign skin lesions.

2.       To assess the safety profile, including immediate and late complications, of fractional CO₂ laser treatment.

Study Design and Setting

A hospital-based prospective interventional study was conducted in the Department of Dermatology, Venereology and Leprosy, VIMS, Ballari, Karnataka, India, from March 2021 to February 2022.

 

Ethical committee clearance was obtained and written informed consent was obtained from all participants.

 

Sample Size and Patient Selection

Sample size was calculated using N = Z²P(1−P)/d², based on data from Cho SB et al. (2011), with 42.9% marked improvement as reference, 95% confidence level, and absolute precision of 0.107. Minimum required size was 83; 100 patients were enrolled for improved statistical power.

 

Inclusion criteria: patients ≥18 years of either sex with benign skin lesions who consented to the procedure.

 

Exclusion criteria: active cutaneous infection in the treatment area, history of keloid/hypertrophic scar formation, isotretinoin use within 6 months, pregnancy or lactation, or uncontrolled diabetes mellitus.

 

Laser Equipment and Procedure

All patients were treated with the FUTURA RF 50 CO₂ Laser (Dermaindia) — a metal-tube RF-excited fractional laser (10,600 nm, spot size 0.1 mm, 50W maximum). CW mode: 2–7 W. Pulse mode: 8–22 W, 0.8–1 ms pulse duration, 50 Hz frequency. Treatment areas were prepared with povidone-iodine; EMLA cream applied under occlusion 60 minutes pre-procedure; local lignocaine infiltration where required.

 

Outcome Assessment

Follow-up was at 1, 4, and 12 weeks post-procedure (telephonic follow-up used for COVID-19-restricted patients). Objective assessment: Global Improvement Scale (GIS) — Grade 0 (no improvement) to Grade 4 (near-total improvement). Subjective assessment: Patient Satisfaction Score (PSS) at 12 weeks — 0 (none) to 8 (excellent).

 

Statistical Analysis

Data analysed using IBM SPSS v25.0. Categorical variables expressed as frequencies and percentages. Chi-square test for associations; P < 0.05 considered statistically significant.

 

 

Demographic Profile

100 patients enrolled (52 male, 48 female; ratio 1.08:1). Age: 49% aged 18–29 years, 35% aged 30–45, 11% aged 46–59, 5% aged ≥60 years. Comorbidities: 90% none, 7% diabetes mellitus, 3% hyperlipidemia.

 

Table 1: Demographic and Clinical Characteristics

 

Lesion Characteristics

Most common site: face (66%), followed by neck (19%) and periorbital region (21% of all lesions). Duration: ≥1 year in 60%, <1 year in 34%, since birth in 6%. Dominant skin type: Fitzpatrick IV (63%), III (33%), V (4%).

 

 

 

 

Table 2: Distribution of Benign Skin Lesions

 

 

Treatment Response and Outcomes

CW mode: 61%; pulse mode: 39%. Complete lesion removal: 95 patients (95%). Of those, 6 patients (6.32%) had recurrence during follow-up; 89 (93.68%) remained recurrence-free.

 

Table 3: Global Improvement Scale and Patient Satisfaction Score

 

Complications

Table 4: Immediate and Late Complications

 

Of the 20 patients who developed PIH, 70% had Fitzpatrick skin type IV and 30% had type III. Five patients were lost to follow-up.

 

Illustrative Cases

Representative before-and-after clinical photographs are presented below for the major lesion types treated in this study. All images were captured under standardised lighting conditions at the VIMS Dermatology procedure room.

 

Acrochordons (Skin Tags)

Complete removal was achieved in all 24 cases using CW mode. Patient satisfaction was excellent (33.3%) or very good (66.7%). No recurrence was observed at 12 weeks.

Figure 1: Acrochordon before and after CO₂ laser ablation

 

Seborrheic Keratosis

Near-total improvement was achieved in 5/6 patients (83.3%); 1 patient showed moderate improvement. Side effects: erythema and PIH. No recurrence at 12 weeks.

 

Figure 2: Seborrheic Keratosis before and after CO₂ laser ablation

 

Dermatosis Papulosa Nigra (DPN)

All 13 patients with DPN achieved near-total improvement using pulse mode. Side effects: erythema and PIH. No recurrence at 12 weeks.

 

Figure 3: Dermatosis Papulosa Nigra (DPN) before and after CO₂ laser ablation

 

Colloid Milia

Near-total improvement in 6/7 patients (85.7%); mild improvement in 1 patient. Side effects: pain, PIH, and scarring. No recurrence at 12 weeks.

 

Figure 4: Colloid Milia before and after CO₂ laser ablation

 

 Syringoma

Near-total improvement in 10/11 patients (90.9%); marked improvement in 1 patient. Side effects: erythema, watery discharge, and PIH. Recurrence in 1 patient at 12 weeks.

 

Figure 5: Periorbital Syringoma before and after CO₂ laser ablation

Melanocytic Nevus

Near-total improvement achieved in all 11 patients using CW mode. Side effects: erythema, watery discharge, and PIH. No recurrence at 12 weeks.

 

Figure 6: Melanocytic Nevus before and after CO₂ laser ablation

 

 Xanthalesma Palpebrarum

Marked improvement in 2/3 patients (66.7%); moderate improvement in 1 patient. All 3 patients had associated hyperlipidemia. Recurrence occurred in all 3 cases within 1 month, underscoring the need for concurrent lipid management.

 

Figure 7: Xanthalesma Palpebrarum before and after CO₂ laser ablation. Note: Recurrence observed in all cases at 1 month; associated hyperlipidemia was present in all patients

 

 

Linear Verrucous Epidermal Nevus (LVEN)

Near-total improvement in 2/5 patients (40%), marked improvement in 2 patients (40%), and no improvement in 1 patient (20%). CW mode used in all cases. Side effects included pain, watery discharge, PIH, and scarring.

Figure 8: Linear Verrucous Epidermal Nevus (LVEN) before and after CO₂ laser ablation

 

Pyogenic Granuloma

Near-total improvement in all 7 patients. CW mode alternating with pulse was used to control bleeding. Side effects: pain, watery discharge, and PIH. No recurrence at 12 weeks.

 

Figure 9: Pyogenic Granuloma before and after CO₂ laser ablation

 

Fibroma

Near-total improvement in both patients with fibroma using CW mode. Side effect: PIH. No recurrence at 12 weeks.

 

Figure 10: Fibroma before and after CO₂ laser ablation

 

Trichoepithelioma

The single patient with trichoepithelioma achieved near-total improvement using CW mode with no side effects or recurrence at 12 weeks.

 

Figure 11: Trichoepithelioma before and after CO₂ laser ablation

 

Post-Inflammatory Hyperpigmentation (Complication)

Post-inflammatory hyperpigmentation was the most common late complication, observed in 20 patients (21%). It was more prevalent in Fitzpatrick skin type IV (70% of PIH cases). The image below demonstrates PIH following CO₂ laser ablation of syringoma.

Figure 12: Post-inflammatory hyperpigmentation (PIH) following CO₂ laser ablation of syringoma

 

Recurrence — Sebaceous Hyperplasia

The single patient with sebaceous hyperplasia showed moderate improvement but developed recurrence at 4 weeks post-procedure. This case illustrates the challenge of treating sebaceous hyperplasia, consistent with its known tendency to recur, as also reported by Kim JH et al.

 

Figure 13: Recurrence after CO₂ laser ablation of Sebaceous Hyperplasia (pre-treatment, 1 week, 1 month post-procedure)

This study demonstrates that fractional CO₂ laser ablation is a highly effective modality for treating a wide spectrum of benign skin lesions. The overall near-total improvement rate of 87% and complete removal rate of 95% compare favourably with existing literature.

 

Sarvepalli et al. (2020) in a split-face study comparing CO₂ laser versus RFA in 70 patients reported near-total improvement in only 38.57% with CO₂ laser. The superior outcomes in our study may reflect lesion-specific laser parameter optimisation and single-session management in most cases.

 

Acrochordons (24%) were the most common lesion, all achieving near-total improvement. DPN (13%) showed 100% near-total improvement, consistent with Bruscino et al. (2014). For syringomas, near-total improvement in 90.9% exceeded the 8.6% reported by Cho et al. (2011), possibly reflecting differences in laser settings and lesion depth.

 

Xanthalesma showed 100% recurrence at 1 month, with all patients having associated hyperlipidemia — underscoring the need for concurrent lipid management alongside procedural treatment. This is consistent with findings by Esmat et al. (2014), who reported 15% recurrence in hyperlipidaemic patients.

 

The PIH rate (21%) exceeded that of Sarvepalli et al. (7.14%), likely reflecting our cohort's predominantly Fitzpatrick type IV skin. Of PIH cases, 70% occurred in type IV patients, highlighting the need for proactive post-procedural photoprotection and topical depigmenting agents in darker phototypes.

 

Limitations include a 12-week follow-up period, which may underestimate late recurrence, and 5 patients lost to follow-up due to COVID-19 pandemic restrictions.

Fractional CO₂ laser ablation is a safe, effective, and well-tolerated modality for the management of a broad spectrum of benign skin lesions. Complete removal in a single session was achieved in 95% of patients with a low recurrence rate of 6.32%. Global improvement was near-total in 87% of cases, and 70% of patients reported very good to excellent satisfaction. Complications were predominantly mild and transient. Particular attention to post-procedural care is warranted in patients with darker skin phototypes to minimise PIH risk. Larger, multicentre studies with longer follow-up periods are recommended to validate these findings.

 

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