High- Versus Low-Density Fractional Laser in the Treatment of Hypertrophic Postburn Scars: A Randomized Clinical Trial

Interventions for postburn pruritus

BACKGROUND

Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are available to control postburn pruritus; however, it remains unclear how effective these are.

OBJECTIVES

To assess the effects of interventions for treating postburn pruritus in any care setting.

SEARCH METHODS

In September 2022, we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched clinical trials registries and scanned references of relevant publications to identify eligible trials. There were no restrictions with respect to language, publication date, or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that enrolled people with postburn pruritus to compare an intervention for postburn pruritus with any other intervention, placebo or sham intervention, or no intervention.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 25 RCTs assessing 21 interventions with 1166 randomised participants. These 21 interventions can be grouped into six categories: neuromodulatory agents (such as doxepin, gabapentin, pregabalin, ondansetron), topical therapies (such as CQ-01 hydrogel, silicone gel, enalapril ointment, Provase moisturiser, beeswax and herbal oil cream), physical modalities (such as massage therapy, therapeutic touch, extracorporeal shock wave therapy, enhanced education about silicone gel sheeting), laser scar revision (pulsed dye laser, pulsed high-intensity laser, fractional CO2 laser), electrical stimulation (transcutaneous electrical nerve stimulation, transcranial direct current stimulation), and other therapies (cetirizine/cimetidine combination, lemon balm tea). Most RCTs were conducted at academic hospitals and were at a high risk of performance, attrition, and detection bias. While 24 out of 25 included studies reported change in burn-related pruritus, secondary outcomes such as cost-effectiveness, pain, patient perception, wound healing, and participant health-related quality of life were not reported or were reported incompletely. Neuromodulatory agents versus antihistamines or placebo There is low-certainty evidence that doxepin cream may reduce burn-related pruritus compared with oral antihistamine (mean difference (MD) -2.60 on a 0 to 10 visual analogue scale (VAS), 95% confidence interval (CI) -3.79 to -1.42; 2 studies, 49 participants). A change of 2 points represents a minimal clinically important difference (MCID). Due to very low-certainty evidence, it is uncertain whether doxepin cream impacts the incidence of somnolence as an adverse event compared to oral antihistamine (risk ratio (RR) 0.64, 95% CI 0.32 to 1.25; 1 study, 24 participants). No data were reported on pain in the included study. There is low-certainty evidence that gabapentin may reduce burn-related pruritus compared with cetirizine (MD -2.40 VAS, 95% CI -4.14 to -0.66; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that gabapentin reduces the incidence of somnolence compared to cetirizine (RR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants). No data were reported on pain in the included study. There is low-certainty evidence that pregabalin may result in a reduction in burn-related pruritus intensity compared with cetirizine with pheniramine maleate (MD -0.80 VAS, 95% CI -1.24 to -0.36; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that pregabalin reduces the incidence of somnolence compared to cetirizine (RR 0.04, 95% CI 0.00 to 0.69; 1 study, 40 participants). No data were reported on pain in the included study. There is moderate-certainty evidence that ondansetron probably results in a reduction in burn-related pruritus intensity compared with diphenhydramine (MD -0.76 on a 0 to 10 numeric analogue scale (NAS), 95% CI -1.50 to -0.02; 1 study, 38 participants). A change of 2 points represents a MCID. No data were reported on pain and adverse events in the included study. Topical therapies versus relevant comparators There is moderate-certainty evidence that enalapril ointment probably decreases mean burn-related pruritus compared with placebo control (MD -0.70 on a 0 to 4 scoring table for itching, 95% CI -1.04 to -0.36; 1 study, 60 participants). No data were reported on pain and adverse events in the included study. Physical modalities versus relevant comparators Compared with standard care, there is low-certainty evidence that massage may reduce burn-related pruritus (standardised mean difference (SMD) -0.86, 95% CI -1.45 to -0.27; 2 studies, 166 participants) and pain (SMD -1.32, 95% CI -1.66 to -0.98). These SMDs equate to a 4.60-point reduction in pruritus and a 3.74-point reduction in pain on a 10-point VAS. A change of 2 VAS points in itch represents a MCID. No data were reported on adverse events in the included studies. There is low-certainty evidence that extracorporeal shock wave therapy (ESWT) may reduce burn-related pruritus compared with sham stimulation (SMD -1.20, 95% CI -1.65 to -0.75; 2 studies, 91 participants). This equates to a 5.93-point reduction in pruritus on a 22-point 12-item Pruritus Severity Scale. There is low-certainty evidence that ESWT may reduce pain compared with sham stimulation (MD 2.96 on a 0 to 25 pressure pain threshold (PPT), 95% CI 1.76 to 4.16; 1 study, 45 participants). No data were reported on adverse events in the included studies. Laser scar revision versus untreated or placebo controls There is moderate-certainty evidence that pulsed high-intensity laser probably results in a reduction in burn-related pruritus intensity compared with placebo laser (MD -0.51 on a 0 to 1 Itch Severity Scale (ISS), 95% CI -0.64 to -0.38; 1 study, 49 participants). There is moderate-certainty evidence that pulsed high-intensity laser probably reduces pain compared with placebo laser (MD -3.23 VAS, 95% CI -5.41 to -1.05; 1 study, 49 participants). No data were reported on adverse events in the included studies.

AUTHORS' CONCLUSIONS

There is moderate to low-certainty evidence on the effects of 21 interventions. Most studies were small and at a high risk of bias related to blinding and incomplete outcome data. Where there is moderate-certainty evidence, practitioners should consider the applicability of the evidence for their patients.

Review of Fractional Nonablative Lasers for the Treatment of Dermatologic Conditions in Darker Skin Phototypes

BACKGROUND

Fractional nonablative lasers (NAFLs) have demonstrated efficacy and safety for treating dermatologic conditions in patients with darker skin phototypes. Nonablative lasers are preferred in darker skin tones due to lower risk of postinflammatory hyperpigmentation.

OBJECTIVE

This review aims to identify the ideal laser options and parameters for treating common dermatologic conditions in patients with skin types IV-VI.

MATERIALS AND METHODS

A comprehensive literature search was conducted on PubMed in May 2023. Of 1,065 articles were identified, and 40 articles met the inclusion criteria. The studies were classified based on design, dermatologic condition, and skin phototype of patients, and assigned levels of evidence according to the Modified Criteria of the Oxford Center of Evidence Based Medicine.

RESULTS

Strong level 1 evidence supports the treatment of melasma and atrophic scars using NAFL. Moderate level 2 evidence was found for using NAFL in acne vulgaris, striae, and skin rejuvenation; 45% of the studies examined skin types III-IV, 20% III-V, 7.5% II-IV, 5% II-V, 5% IV alone, and 2.5% I-IV.

CONCLUSION

Further research is needed to determine the optimal treatment modalities and parameters for skin types V and VI. Appropriate device selection and conservative treatment settings are crucial for optimizing outcomes and minimizing adverse events.

Human dermal fibroblast-derived extracellular matrix reduces postinflammatory hyperpigmentation after fractional carbon dioxide laser facial resurfacing in Asians

BACKGROUND

Extracellular matrix (ECM) components promote the development of skin wounds by providing biological scaffolds and regenerative microenvironments.

AIMS

To evaluate the beneficial effects of human dermal fibroblast-derived ECM after fractional carbon dioxide laser resurfacing in Asians.

PATIENTS/METHODS

In this double-blind, randomized, vehicle-controlled, split-face study, 15 participants with features of facial skin aging were treated with a single session of fractional carbon dioxide laser, followed by the application of either ECM (ECM group) or placebo (control group). In vivo skin parameters were measured at baseline and after 4 and 12 weeks of treatment using the Antera 3D®, Cutometer® MPA580, Dermascan®, and Tewameter®.

RESULTS

A total of 14 participants (mean age 45.1 ± 9.7 years) completed the study. The change in melanin level was significantly lower in the ECM group than in the control group at week 12 (p < 0.05). Transient increase in erythema level was observed at week 4 in the control group, and the change in the erythema level was greater in the control group than in the ECM group (p = 0.014). Though the ECM group showed improvements in the dermal density, texture, transepidermal water loss, marionette lines (volume, maximum depth, and average depth), and nasolabial folds (volume, maximum depth, and length), no significant differences were found between the two groups. Treatment-related adverse events were not reported.

CONCLUSIONS

We suggest that human dermal fibroblast-derived ECM may be used as adjunctive therapy after fractional carbon dioxide resurfacing to prevent postinflammatory hyperpigmentation in Asians.

An Updated Review of Hypertrophic Scarring

Hypertrophic scarring (HTS) is an aberrant form of wound healing that is associated with excessive deposition of extracellular matrix and connective tissue at the site of injury. In this review article, we provide an overview of normal (acute) wound healing phases (hemostasis, inflammation, proliferation, and remodeling). We next discuss the dysregulated and/or impaired mechanisms in wound healing phases that are associated with HTS development. We next discuss the animal models of HTS and their limitations, and review the current and emerging treatments of HTS.

Analysis of Energy and Density in Treating Hypertrophic Scar After Burn in Children with CO2 Dot Matrix Laser

Objective: To analyze and compare the effect of the combination of energy and density parameters of CO2 dot matrix laser in the hyperplastic stage of pediatric burn. Materials and Methods: A total of 160 pediatric patients with hypertrophic scar after limb burn from 2017 to 2020 were randomly divided into four parameter groups (n = 40). The patients were treated with ablative fraction carbon dioxide laser, once every 10 weeks. During the interval of laser treatment, Compound Heparin Sodium and Allantoin Gel (Contractubex) was applied externally, tid, and elastic cover or elastic bandage is attached to the affected limb. Scoring based on the Vancouver Scar Scale is performed before each laser treatment, The score before the first treatment was the initial score, which was scored by two people separately, and the average score was calculated. Subsequently, the patients were treated four times and scored. The differences between each treatment and the first score of each parameter group were compared. Under the same energy and different treatment density, the scores after each treatment were compared. Under the same density and different energy, the scores after each treatment were compared. The bleeding and pigmentation of each parameter group were compared. Results: The increase of density can show the therapeutic effect earlier than the increase of energy, and 25mj energy and 10% density have better intervention effect. With the course of disease and the progress of treatment, the correlation between intervention effect and parameters tends to weaken. Comparing the number of cases with different scores between each treatment and the first time, the score in the 5% density group was lower than that in the 10% density group, but there was no significant difference between the 25mj and 17.5mj energy levels in the same density group. The intervention effect of the increase of density on scar was better than that of energy, and the increase of energy and density could aggravate the pain. Conclusion: In pediatric burn hypertrophic scars treated by CO2 dot matrix laser in exfoliation mode, the intervention effect of increasing density is better than that of energy. When setting laser treatment parameters, we should give priority to increasing density and adjust energy according to the effect of treatment and the condition of pain, bleeding and color precipitation. In this study, the best combination of parameters is 17.5mj/10%.

Combination of ablative fractional carbon dioxide laser and platelet-rich plasma treatment to improve hypertrophic scars: a retrospective clinical observational study

BACKGROUND

Hypertrophic scars are one of the main complications that affect the quality of life of patients after burns. Many methods have been shown to be effective in the treatment of hypertrophic scars, such as ablative fractional CO₂ laser (AFCL) and platelet-rich plasma (PRP). However, there are few studies on the effect of the combined application of these measures. The purpose of this study was to explore the therapeutic effect of AFCL combined with PRP on hypertrophic burn scars.

METHODS

A retrospective clinical observation study was conducted on 50 patients with hypertrophic burn scars. The AFCL+PRP group included 31 patients who received AFCL combined with PRP treatment; the AFCL group included 19 patients who received AFCL treatment only. The University of North Carolina 4P Scar Scale (UNC4P) and the Vancouver Scar Scale (VSS) scores that were collected before each treatment were used as indicators of the effectiveness of the previous treatment. The scores recorded at the second, fourth and seventh months were analysed.

RESULTS

The demographic data of the 2 groups were not significantly different. Before treatment, there was no difference in the UNC4P and VSS scores between the 2 groups. There was a significant decline in the UNC4P and VSS total scores over 6 months in both groups (p < 0.05) and scores in the 2 groups were comparable after 3 and 6 months (p < 0.05). UNC4P scores in the AFCL+PRP group decreased from a mean of 8.26 to 2.61 (p < 0.05) with a concomitant drop in VSS scores from a mean of 11.74 to 6.06 (p < 0.01). In the AFCL group UNC4P and VSS scores decreased from 7.68 to 4.63 (p < 0.05) and from 10.89 to 8.16 (p < 0.05), respectively. The sub-items of these 2 assessments were analysed and the results suggest that AFCL combined with PRP can comprehensively improve scarring.

CONCLUSIONS

This study shows that PRP is an effective adjunct for AFCL in the treatment of hypertrophic burn scars and that the combination of PRP and AFCL proved to be more useful than AFCL alone. This combination may be a new and effective clinical practice for the treatment of scars. However, larger and higher-level clinical studies are still needed to determine its efficacy and possible mechanisms.

A Comparative Study on the Efficacy of Fractional CO2 Laser and Fractional CO2 Laser with Autologous Platelet-Rich Plasma in Scars

Context

Surgical correction of scars may not be an ideal solution in all cases and hence it is desirable to have a nonsurgical option available. Autologous platelet-rich plasma (PRP) and fractional carbon dioxide laser (FCL) offer an alternative treatment modality.

Aims

To compare the efficacy and safety of FCL and intradermal PRP with FCL in the management of postburn and posttraumatic scars.

Settings and Design

A prospective, randomized, observer-blinded, comparative study was conducted at a hospital skin centre from Oct 2016 to Sep 2018.

Subjects and Methods

A total of 67 patients with scars were randomly divided into two groups; Group I was treated with four sessions of monthly FCL and Group II was treated with four sessions of PRP and FCL. The patients were assessed using the Patient and Observer Scar Assessment Scale (POSAS) at baseline and 4 weeks after each session.

Statistical Analysis Used

For continuous variables, the summary statistics of mean ± standard deviation was used; for categorical data, number and percentage were used. Chi-square (χ2) test was used for association between two categorical variables. P value <0.05 was considered to be statistically significant.

Results

Thirty cases in each group completed the study. There was a significant improvement in the total score of POSAS (p < 0.001) in both groups, but the final difference between the two groups was not statistically significant (p = 0.793 and P = 0.278, respectively).

Conclusions

Fractional CO2 laser causes significant improvement in scar appearance. PRP in combination with FCL offers no additional advantage.