Striae distensae (stretch marks, striae atrophicae) are atrophic linear dermal scars with overlying epidermal atrophy. It has been suggested that striae develop as a result of stress rupture of connective tissue framework and do not cause any significant medical problem, but can cause significant distress to those affected 1. Successful treatment of striae distensae has always been challenging; microdermabrasion and microneedling appear to be capable of generating collagen and other dermal matrix components, which may ‘fill in’ contour deformities as seen with striae distensae 2.
Skin microneedling, collagen induction therapy, needle dermabrasion, or dermaroller therapy is a dermatologic treatment performed to achieve percutaneous collagen induction to smooth wrinkles, improve depressed acne scarring, and reduce the appearance of stretch marks. Skin needling creates dermal damage without the removal of the healthy epidermis. This dermal damage induces the release of growth factors that stimulate the production of new collagen and elastin in the upper dermis 3,4.
Microdermabrasion (aluminum oxide crystals) appears to be a procedure that can produce changes in dermal matrix constituents and results in improvement in skin contour irregularities. It is a popular technique used in the treatment of several skin problems including acne, acne scarring, striae distensae, and photoaging. However, studies documenting the efficacy of microdermabrasion in the treatment of striae distensae are lacking 5.
The aim of this work was to evaluate the efficacy and tolerability of microneedling (dermaroller) versus microdermabrasion (aluminum oxide crystals) in the treatment of striae distensae.
Patients and methods
The present study was carried out on 30 patients with striae distensae (rubrae and albae) with skin phototype III–IV. They were selected from the Outpatient Clinic of the Dermatology and Venereology Department, Tanta University Hospitals, from the period of July 2011 to December 2013. The study was approved by the Research Ethics Committee of Faculty of Medicine, Tanta University, Tanta, Egypt. All participants signed an informed consent before participation in the study. Patients with a history of coagulation defects, blood diseases, scar formation, chronic debilitating diseases, corticosteroid therapy, pregnant women, and patients with unrealistic expectations were excluded.
All patients were subjected to a complete assessment of history, including history of any cause (rapid weight gain or loss, systemic steroid intake, exercise, and pregnancy), and general and dermatological examinations.
Patients were classified into two groups; group I included 15 patients who were treated with microneedling and group II included 15 patients who were treated with microdermabrasion. Each patient received six sessions of treatment at a 2-week interval.
Microneedling technique 6
The microneedle used had a width of 2 cm, studded with a fine needle of medical-grade stainless steel. The needle length was 1.5 mm. According to the pressure applied, the needle penetrated the skin from 0.1 to 1.3 mm. The skin of the lesion was cleansed by scrubbing with cotton gauze soaked in 70% ethanol. The dermaroller was moved over the lesion in vertical, horizontal, and oblique directions, with five passes in each direction. During the session, the bleeding points were controlled with light pressure with sterile gauze soaked with saline ice packs for a few minutes after the end of the sessions. An emollient cream was applied for each patient. Each patient received at least six sessions of treatment with a 2-week interval.
Microdermabrasion technique 7
Before each session, the lesion was cleansed by scrubbing with cotton gauze soaked in 70% ethanol. Microdermabrasion with aluminum oxide crystals was performed by microdermabrasion deep clean (Estetic Italia, Pesaro, Italy). The handpiece of the machine was moved over the lesion several times with steady pressure. More pressure can applied until pinpoint bleeding is observed.
The depth of the treatment depends on the strength of flow of crystals; the movement of handpiece against the skin and the number of passes over the treated area, slower movement of handpiece (allowing longer contact of the abrasive crystals with the skin), and more passes lead to deeper abrasion. An emollient cream was prescribed to the patient twice daily. Each patient received at least six sessions of treatment at a 2-week interval.
Assessment of the clinical efficacy of the therapeutic procedures
Photographs were taken for the lesions at baseline after each session of treatment and monthly during the follow-up period. Two dermatologists were asked to record the percentage of improvement for each patient after the end of the treatment.
The clinical efficacy of treatment was categorized as follows 8: excellent improvement, disappearance of more than 75–100% of lesions; marked improvement, more than 50–75%; moderate improvement, more than 25–50%; and minimal or no improvement, disappearance of less than 25% of lesions.
The patients were asked at the final visit to rate the overall satisfaction according to whether the patient was not satisfied, somewhat satisfied, or highly satisfied.
Safety and tolerability assessment in terms of edema, erythema, pain, crustation, infection, and postinflammatory hyperpigmentation was performed. The patients were followed up monthly for 3 months after the last session to detect any recurrence or complications.
Histopathological examination: a 3 mm punch biopsy specimen was obtained from the lesion (only from 10 patients, five from each group) before treatment and after the end of the follow-up period. The biopsy specimens were stained by hematoxylin and eosin (H&E) stain and masson trichome stain to study the histopathological changes.
Statistical analysis of the data
Statistical presentation and analysis of the present study were carried out; continuous variables are presented as mean±SD and discrete variables are shown as percentages. Both w2 and Fischer w2 testing were used for intergroup comparisons, and P less than 0.05 was considered significant. Software (SPSS, version 16.0 statistical package for Microsoft Windows; SPSS Inc., Chicago, Illinois, USA) was used throughout the study.
In this study, there was no significant difference between both groups in the clinical data of the patients (Table 1).
In terms of the degree of improvement of striae distensae, in group I, three (20%) patients showed minimal improvement, two (13.3%) patients showed moderate improvement, four (26.7%) patients showed marked improvement, and six (40%) patients showed excellent improvement (Figs 1–3). In group II, two (13.3%) patients showed no improvement, six (40%) patients showed minimal improvement, four (26.7%) patients showed moderate improvement, and three (20%) patients showed marked improvement (Figs 4 and 5). There was a statistically significant clinical improvement in group I than group II (P=0.005) (Table 2).
In terms of patients’ satisfaction, in group I, five (33.3%) patients were somewhat satisfied and 10 (66.7%) patients were highly satisfied, whereas in group II, four (26.7%) patients were not satisfied, eight (53.3%) patients were somewhat satisfied, and three (20%) patients were highly satisfied. There was a statistically significant difference between the two groups, with more satisfaction in group I than group II (P=0.015).
In terms of the relation between clinical efficacy and type of striae distensae, in group I, among 11 patients with striae rubra, one (9.1%) patient showed moderate improvement, four (36.4%) patients showed marked improvement, and six (54.5%) patients showed excellent improvement. Among four patients with striae alba, three (75.0%) patients showed minimal improvement and one (25%) patient showed moderate improvement. There was a statistically significant improvement in patients with striae rubra than alba (P=0.003), whereas in group II, among nine patients with striae rubrae, two (22.2%) patients showed minimal improvement, four (44.4%) patients showed moderate improvement, and three (33.3%) patients showed marked improvement. Among six patients with striae alba, all patients (100%) showed minimal or no improvement. There was a statistically significant improvement in patients with striae rubra than striae alba (P=0.005) (Table 3).
In terms of the relationship between the clinical efficacy and site of striae distensae, there was no significant difference between group I and group II.
In terms of the safety and tolerability of therapy in this study, in group I, pain, erythema and pruritus were reported in all patients (both striae alba and rubra) and were treated with an emollient cream and improved within 48 h, whereas in group II, there was good tolerability in all patients.
Before treatment, sections stained with H&E showed thinning and flattening of the epidermis. Dermal collagen fibers were arranged in straight lines with dermal edema and heavy perivascular lymphocytic infiltration around small dermal blood vessels. At the end of the follow-up period, patients treated with microneedling showed an increase in the thickness of the epidermis with an increase in collagen fibers in the dermis and showed some mild perivascular inflammatory cells. However, in patients treated with microdermabrasion, the specimens showed a mild increase in epidermal thickness and collagen fibers stretched in the dermis more than before treatment, but less than sections of striae treated with microneedling, in addition to prominent perivascular cell infiltration (Fig. 6).
Before treatment, sections stained with masson trichrome showed stretched collagen bands in the upper third of the dermis parallel to the epidermis with mild dermal edema. At the end of the follow-up period, sections of striae in patients treated with microneedling showed a marked increase in collagen fibers in the dermis parallel to the epidermis, whereas sections of patients treated with microdermabrasion showed a moderate increase in collagen fibers (Fig. 7).
Successful treatment of striae distensae has always been challenging. Although several treatment modalities have been proposed, no consistent modality is available. Microdermabrasion (aluminum oxide crystals) has become a popular method of resurfacing 5. Microneedling provides an effective method to treat scars, wrinkles, and skin laxity 3,8.
In this study, microneedling showed a statistically significant clinical improvement than microdermabrasion in the treatment of striae distensae. Also, there was a statistically significant increase in clinical efficacy and improvement in striae rubrae than striae alba.
In the current study, 66.7% of the patients treated with microneedling showed marked to excellent results. Park et al. 8 carried out a study evaluating the efficacy of microneedling in the treatment of striae distensae in six sessions/2 weeks; 43.8% of patients showed marked to excellent improvement and 56.2% showed minimal to moderate improvement. Their results were less accurate than the present study because most of the patients in their study had striae alba and microneedling was more effective in striae rubra than striae alba. Also, Ryu et al. 9 carried out a study evaluating the efficacy of fractionated microneedle radiofrequency and fractional carbon dioxide laser in the treatment of striae distensae; all patients showed marked to excellent improvement because they used a combination of fractionated microneedle radiofrequency and fractional carbon dioxide laser.
It has been postulated that needles of dermarollers have their own electrical potential that triggers the proliferation of fibroblasts 10. The body reacts to any epithelial injury with electrical signals that control the cascade of wound-healing mechanisms. Under normal conditions, the interior of skin cells has a resting electrical potential of 70 mV. The extracellular space as well as the skin’s surface are charged positively. If an epithelial injury occurs, the skin cells release potassium and proteins, which in return alter the conductivity of the interstitium. At the same time, the innercellular potential increases considerably to 120 and more mV. This potential difference forces fibroblasts to migrate to the point of injury and finally forces them to proliferate and transform into collagen fibrils. Revascularization and neocollagenesis fill up the atrophic scar tissue 11,12.
Among patients treated with microdermabrasion, 46.7% showed moderate to marked improvement and 53.3% showed minimal improvement. Also, Abdel-latif and Albendary 13 evaluated the efficacy of microdermabrasion in the treatment of striae distensae with five sessions at weekly intervals; 50% of patients showed moderate to marked and 50% of patients showed minimal to mild improvement.
Microdermabrasion is a procedure that can produce alterations in dermal matrix constituents and result in improvement in skin contour irregularities; it may be beneficial in improving transepidermal delivery of certain medications 7. Skin microdermabrasion involves mechanical abrasion of the skin using a pressurized stream of abrasive particles such as aluminum oxide crystals. There is superficial wounding of the skin, followed by epithelization and stimulation of epidermal cell turnover, and it may also cause stimulation and remodeling of dermal collagen 14.
In the current study, there was a significant relation between the degree of improvement in both procedures and the duration of stria distensae. Also, this was in agreement with the results of Garciae 15, who suggested that the treatment of striae distensae was more effective during the active stage, short duration (striae rubra) before scarring process, long duration (striae alba) is completed.
In the present study, there was no significant relation between the degree of improvement in both procedures and the anatomical site. These results were in agreement with Adatto and Deprez 16, who reported that there was no significant relation between the clinical efficacy of sand abrasion, followed by 15% trichloroacetic acid in the treatment of striae distensae and anatomical site.
In this study, there were minimal erythema, pain, and slight pruritus during treatment sessions in all patients treated with microneedling and all of them improved within 48 h. Also, Park et al. 8 found that treatment of striae distensae by a dermaroller was well tolerated, with only minor side effects during and after treatment, including pain, erythema, and pruritis. Ryu et al. 9 found that treatment of striae distensae with a combination of microneedle and fractional carbon dioxide laser was well tolerated.
Although patients treated with microdermabrasion reported no side effects, another study reported that 20% of patients with striae distensae and treated with microdermabrasion showed postinflammatory hyperpigmentation and 25% showed transient erythema 13.
In terms of the histopathological changes in striae distensae after the end of the treatment and follow-up period, in patients treated with microneedling, the epidermis increased in thickness, perivascular inflammatory cell infiltrate decreased, and collagen fibers increased in the dermis compared with before treatment. However, in patients treated with microdermabrasion, the epidermis increased in thickness with collagen fibers stretched in the dermis more than before treatment, but less than sections of striae distensae treated with microneedling. This may indicate the greater clinical efficacy of microneedling in the treatment of stria than microdermabrasion.
In agreement with the current study, Aust et al. 3 reported a marked increase in collagen and elastic deposition and 40% thickening of the stratum spinosum after needling therapy of striae distensae. Kim et al. 17 showed that microneedle therapy induced a larger increase in collagen deposition than intense pulsed light. Moreover, Shim et al. 18 found that the stratum corneum was homogenized and focally compact, and epidermal hyperplasia decreased melanization and increased elastin deposition in the dermis after 12–14 weeks of microdermabrasion treatment of striae distensae.
Microneedling showed more significant clinical efficacy than microdermabrasion in the treatment of striae distensae, but microdermabrasion showed more significant tolerability. Both microneedling and microdermabrasion were more effective for the treatment of striae rubrae than striae alba; thus, treatment of striae lesions must be started early, whereas in late lesions (alba), more than one therapeutic modality has to be used.
We acknowledge Dr. Engi Khalifa for her help in this study.
Conflicts of interest
There are no conflicts of interest.