Striae Distensae: A Comprehensive Review and Evidence-Based Evaluation of Prophylaxis and Treatment

S. Al-Himdani; S. Ud-Din; S. Gilmore; A. Bayat

The British Journal of Dermatology. 2014;170(3):527-547.

Results

Epidemiology and Quality of Life

Striae distensae can occur in adolescence, pregnancy and obesity.^{[2,3,6,8,22,23]} The prevalence cited is equally diverse in these groups and ranges from 43% to 88% and 6% to 86%, in pregnant women and adolescents, respectively.^{[2,6,7,8,20,24,25,26,27]} Among obese individuals of body mass index (BMI) 27-51, the prevalence is reported to be 43%.^[22] Studies in other patient groups such as non-pregnant women and adult males also report varied prevalences ( Table 2 ).^[4,10,27,28]

Geographically disparate studies of SD demonstrate similar micro- and macroscopic appearances.^[2,24,25] However, inter-racial differences in the severity of SD have been observed in a study carried out by Elbuluk et al.^[30] Of 48 women evaluated, African-American women were more severely affected than white women within the same geographical region. The authors did also note that there was a difference in BMI and smoking status between the two groups, which may indicate that other factors aside from race are involved.

Prevalence and anatomical regions affected vary depending upon sex and age ( Table 2 ). In adolescents, approximately 40% of male and 70% of female subjects are affected.^[2,3] In adolescent males the lower back and knees are usually affected whilst in female subjects the thighs and calves are more often involved. During pregnancy, the abdomen and breasts are common sites for SD (Figure 1).

(Enlarge Image)

Figure 1.

Striae distensae. Areas typically affected by striae distensae in (a) adolescent males (n = 131), (b) adolescent females (n = 131) and (c) pregnant women (n = 110). Values represent the percentage of patients with striae in each area.[2, 8]

Yamaguchi et al. elucidated a significant difference in the 'emotion' score of a validated questionnaire (Skindex-29) in Japanese women with SD compared with those without SD.^[31] Although this study is limited by its lack of racial diversity, the psychological impact of SD is evident.

Risk Factors and Aetiology

Most SD research has focused on pregnant women and adolescents. A positive family history is a risk factor in both of these groups alike.^[26,32] Among adolescents, BMI and childhood obesity both influence risk of developing SD.^[2] Other important risk factors and associations have been reported (Figure 2). Risk factors in pregnant women may be constitutional or pregnancy related ( Table 3 ).^[28] Constitutional factors include maternal age and BMI. Younger women more commonly develop SD, implicating a constitutional difference in the stretching ability of the skin in younger women.^{[5,7,8,20,24,25,28]} The association of pregnancy-associated factors such as birthweight, gestational age, weight gain during pregnancy and polyhydramnios with the occurrence of SD support the theory that the changes associated with pregnancy also play a role in their development.^[5,20,24] Numerous clinical conditions, surgical interventions and medications have been associated with SD ( Table 4 ).^{[8,13,33,34,50,51,52]}

(Enlarge Image)

Figure 2.

Risk factors and associations with striae distensae.[2, 7–9, 20, 24–26, 30] BMI, body mass index.

Striae distensae are also described in monozygotic twins,^[53] in a familial form^[54] and in Marfan syndrome,^[33] indicating an important genetic predisposition. This is supported by biopsy findings that report slower migration and proliferation rates in fibroblasts of patients with SD.^[55] Three main theories relating to SD formation are described: mechanical stretching of the skin, hormonal changes and an innate structural disturbance of the integument. Mechanical stretching of the skin is postulated due to the perpendicularity of SD to the direction of the skin.^[15] However, contradictory studies dispute this theory. While a greater degree of physiological stretching would be expected with increased abdominal girth in pregnancy and on the extensor surfaces of joints, the latter shows no significant increase in the frequency of SD.^[54,56]

Striae distensae are often encountered in states in which hormonal alterations occur. Adrenocorticotrophic hormone and cortisol are thought to promote fibroblast activity, leading to increased protein catabolism and thus alterations to collagen and elastin fibres.^[57] Additionally, increased urinary excretion of corticosteroids (17-ketosteroid) has been reported in patients with SD.^[58] Pregnancy-related hormones are also believed to influence SD formation.^[8,59,60,61] Cordeiro et al.^[59] described increased oestrogen and androgen receptors in skin exhibiting SD compared with normal skin. Lower serum relaxin levels were demonstrated in pregnant women with SD compared with those without SD at 36 weeks' gestation by Lurie et al.^[61] The connective tissue in skin types with less relaxin would be expected to be less lax and thus at greater risk of structural disruption of the elastic fibre network during stretching than more lax skin with greater relaxin content. Salter et al. identified a positive correlation between the presence of SD and prolapse in 108 women. More than half of the women with prolapse reported SD compared with only 25% in the non-prolapse group. Both conditions have been associated with decreased collagen content.^[60] Reduced expression of procollagen and fibronectin genes in SD tissue was described by Lee et al.^[16] In a similar way to keloid disease and scleroderma, which are thought to develop due to disordered gene expression of the extracellular matrix,^[62,63] SD may also present altered gene expression, contributing to their formation.

Histopathogenesis of Striae Distensae

Striae rubrae and striae albae are distinct, evolutionarily linked forms of SD.^[8] Their distinction has therapeutic implications ( Table 5 , Fig. 3).^[72] In addition to their contrasting macroscopic appearances, distinctions can be made based on their ultrastructural appearances.^[68–70] Hermanns and Piérard^[64] described two additional types of SD, striae nigrae and striae caerulea, which occur in those with darker skin due to increased melanization. The colour of the SD is related to the stage of evolution and to melanocyte mechanobiological influences.^[65]

(Enlarge Image)

Figure 3.

Striae distensae. Photographs and histological comparisons of normal skin (a, b), striae rubrae (c–e) and striae albae (f–h). Haematoxylin and eosin staining. (a) Normal skin histology; (b) haphazardly arranged small collagen fibres and thin elastin fibres in the papillary dermis, surrounded by ground substance; coarse elastic fibres and thick bundles of collagen parallel to the direction on the skin in the reticular dermis. (c) Striae rubrae are tense, red and erythematous; (d, e) fine elastic fibres predominate in the dermis with thicker tortuous fibres in the periphery;¹⁷ there is a reduction and reorganization of elastin and fibrillin fibres and structural changes in collagen are seen.[16, 66, 68, 69, 71] (f) Striae albae appear pale, depressed and wrinkled; (g,h) histology demonstrates epidermal atrophy and loss of the rete ridges; densely packed, thin eosinophilic collagen bundles are arranged horizontally, parallel to the surface of the skin in a similar way to in a scar.[64–66, 68–70]

Early histopathological dermal alterations may be visualized on electron microscopy, including mast cell degranulation and macrophage activation leading to elastolysis of the mid-dermis.^[73] Release of enzymes by mast cells, including elastases, is proposed as a key initiatory process in SD pathogenesis.^[66] As well as the inflammatory process, alterations in collagen, elastin and fibrillin content have been characterized (Fig. 3). The reorganization of fibrillin and elastin are thought to play an important role in SD pathogenesis and those predisposed to developing SD may have an underlying deficiency of fibrillin.^[68]

Evaluation and Severity of Striae Distensae

A universal approach to evaluating the severity of SD does not exist. Visual scoring and imaging modalities have been reported in the literature ( Table 6 ). Approaches to evaluating SD severity visually include the Davey^[9] and Atwal scores,^[20] although these have not been validated specifically for SD.

For an objective evaluation of skin topography, imaging devices may be used, including three-dimensional (3D) cameras, reflectance confocal microscopy and epiluminescence colorimetry.^[64,74,75] These provide a means of evaluating a response to treatment on an ultrastructural level although they have not yet been validated for use specifically in SD. Epiluminescence colorimetry and dermoscopy may be used to identify SD colour. As treatment response varies according to the colour, this may play a therapeutic role in targeting SD based on colour in order to obtain the best treatment outcomes.^[64]

Treatment

A treatment modality that is consistently effective with minimal adverse effects does not exist to date. Not only does therapeutic outcome depend on the type of SD but also the patients' Fitzpatrick skin type.^[65] Most adverse effects, particularly with lasers, occur in patients with darker skin types (Fitzpatrick skin types III–IV).^[79] Lifestyle measures such as exercise were demonstrated by one study to have no effect on SD.^[35]

Topical agents. A number of topical agents have been evaluated ( Table 7 ). Tretinoin is thought to work through its affinity for fibroblasts and induction of collagen synthesis.^[11,80,81] It has maximal efficacy in striae rubrae and poor, unpredictable responses in striae albae.^[11,94,95] In a double-blind randomized control trial by Kang et al., 26 white subjects received either treatment (0·1% tretinoin) or vehicle cream. The cream was applied once a day for 24 weeks. Length and width measurements of SD, punch biopsies and both objective and subjective evaluations were reported outcome measures. The severity of SD was rated at each visit on a scale: mild (0-3), moderate (4–6) or severe (7-9). A statistically significant reduction in the mean length and width (14% and 8%, respectively) were reported following treatment. After 6 months, 80% (n = 8) of the tretinoin-treated patients had definite marked improvement compared with 8% (n = 1) in the vehicle-treated group. No significant differences were found on histological assessments.^[80]

Creams, lotions and ointments are used by up to 78% of pregnant women, thus incurring a significant expense.^[31,96] They are commonly targeted at pregnant women at risk of developing striae gravidarum during pregnancy.^[97] A Cochrane review undertaken in 2012 evaluated six topical agents in over 800 women and found no statistically significant evidence to support their use in the prevention of SD.^[96] The studies included were relatively small and included women at different stages in their pregnancy. Creams evaluated included Alphastria®, Trofolastin®, cocoa butter, olive oil and Verum®.

Trofolastin cream contains Centella asiatica, which is thought to stimulate fibroblasts and has an antagonistic effect against glucocorticoids.^[98] Mallol et al.^[73] applied Trofolastin or placebo cream to 41 and 39 women, respectively, in a double-blind randomized controlled trial (RCT). Application was to the abdomen, breasts, buttocks and hips. Checks during pregnancy evaluated the degree of striae using an arbitrary, nonvalidated score (0, no striae; 1, few and thin striae; 2, many thin striae or few thick striae; 3, many thick striae). The authors report that 22% fewer women developed SD in the prophylactically treated group compared with the placebo group, following daily application of cream to the abdomen, breasts, buttocks and hips during pregnancy. However, this study may have a degree of attrition bias, with 20% incomplete outcomes reported (100 women took part yet only 80 were in the final analysis). It is stated that this was mostly due to 'address change' (n = 19). Additionally, there are no details regarding how women were allocated to either the treatment or placebo groups.

Many cocoa butter products are marketed and are easily accessible for use in the prevention and treatment of SD. Buchanan et al.^[19] evaluated the efficacy of the cream in a double-blind RCT. A total of 150 women were treated with the cocoa butter and an equal number applied placebo cream daily to all four quadrants of the abdomen. Women were enrolled before 16 weeks of pregnancy. At 26 and 36 weeks of pregnancy and at delivery the Davey method was used to evaluate the stretch mark severity by different observers using photographs. Authors report that there was no significant difference between patients developing SD in the cocoa butter and placebo groups. The exact method of allocation of pregnant women to either treatment or placebo groups in this study is unclear.

Ud-Din et al.^[82] conducted a double-blind RCT evaluating the effect of topical silicone and placebo gel applied to two sides of the abdomen of 20 women. Following daily application, outcomes were evaluated using biopsies, tissue tonometry, full-field laser perfusion imaging, spectrophotometric intracutaneous analysis and subjective evaluation. Results demonstrated increased melanin and decreased haemoglobin, collagen and pliability over the 6-week period in both groups. Histology also demonstrated a reduction of rete ridges on both sides. These findings indicate a potential beneficial effect of massage on SD. Compared with placebo, increased collagen and reduced pigmentation in the silicone-treated group was reported. Although this study demonstrates positive results, it is limited by the relatively small number of patients.

Chemical/mechanical debridement techniques. Acid-peel treatments such as glycolic acid (GCA) and trichloroacetic acid (TCA) are thought to act by increasing collagen synthesis.^[90,91,99] Mazzarello et al.^[93] undertook a double-blind RCT of 40 women to assess the effect of 70% GCA topical therapy on SD of the thigh. Patients were divided into two groups: striae albae and striae rubrae. In each group, patients applied the treatment to the left thigh and a placebo to the right thigh with a total of six applications over 6 months. Reported outcome measures included skin texture analysis using scanning electron microscopy as well as haemoglobin and melanin levels using spectrophotometry. After treatment, the striae rubrae group demonstrated a significant decrease in furrow width and in haemoglobin. The striae albae group demonstrated a similar decrease in furrow width and an increase in melanin. No significant differences were reported in parameters of the placebo-treated areas. Although outcomes appear positive, there is no report of randomization in this study and details regarding how patients were allocated to each group are lacking. Although the authors state that this is a double-blinded study, the details of how blinding was undertaken are not clear. The correct concentration should be applied, as higher levels may result in irreversible scarring.^[100,101]

Microdermabrasion is a skin resurfacing technique using aluminium oxide.^[102] It has been reported to increase type-I collagen and have a greater effect on striae albae.^[103]

Nonablative laser techniques. These lasers target haemoglobin or melanin and several have been utilized in studies on SD including: the 585-nm pulsed-dye laser (PDL), the 1064-nm neodymium-doped YAG (Nd-YAG),^[36] the 308-nm xenon chloride (XeCl) excimer laser and the 577-nm copper bromide laser^[104] ( Table 8 ). Few studies evaluating the efficacy of laser therapies in SD are of high level evidence. These studies are understandably difficult to blind, but a significant proportion of the studies also lack controls. Therefore outcomes need to be interpreted carefully.

The 585-nm PDL is a vascular laser that targets dilated blood vessels in striae rubrae and is reported to increase the collagen content of SD.^[105] McDaniel et al.^[106] undertook a controlled study of 39 patients with SD. Treatment sites included the abdomen, thighs and breasts. Four treatment protocols were used with different spot distances and fluences. Untreated SD acted as controls. Outcomes were measured by subjective analysis, shadow profilometry and histopathological analysis. A significant reduction in skin shadowing was reported in patients with SD in all protocols compared with controls. Additionally, elastin regained its normal appearance in SD treated with low-fluence PDL. The principal investigator who undertook the subjective analysis was not blinded to the treatment protocols.^[106]

The 308-nm XeCl excimer laser is an ultraviolet (UV) laser and has been used to treat SD.^[120] Alexiades-Armenakas et al. conducted an RCT of 31 patients with hypopigmented lesions, of which 9 were SD. Lesions were randomized by alternate allocation to receive treatment or not. Treatments were performed at biweekly intervals then fortnightly until either a maximum of 10 treatments were undertaken, or 75% increase in colorimetric measurements relative to baseline or 100% visual pigment correction was obtained. Outcome measures included visually assessed pigment correction relative to control (assessed by three blinded observers) and skin pigmentation levels measured on a colorimeter. A statistically significant improvement in pigmentation on the colorimetric assessment was identified in treated SD vs. site-matched controls. Improved visual pigmentation level compared with controls was also reported but this declined towards baseline after 6 months. Alternate allocation in this study carries a high risk of selection bias. There was also no mention of whether the investigator or patients were blinded to treatment. Attrition bias may be another concern as there is no report of how many patients were in the final analysis.

Ablative laser treatment. This includes the short-pulsed 10 600-nm CO₂ laser. These lasers trigger epidermal vaporization and coagulation of the underlying dermis.^[79] They present a risk of hyperpigmentation, particularly in those with darker skin.^[79,130]

Light therapy and radiofrequency devices. Intense pulsed light (IPL), radiofrequency (RF) and UV radiation therapy have been used in studies to treat SD ( Table 8 ). IPL emits visible light with a spectrum of 515–1200 nm, which helps to organize collagen fibres. Repeated sessions may be required to maintain positive effects.^{[100,108,109,110]} RF devices increase collagen production by inducing collagen type I mRNA expression.^{[105,111,131]} They produce heat, which converts electrical current to thermal energy that is uniformly dispersed to different tissue depths.^[105,111]

Fractional resurfacing. Fractional photothermolysis is a laser resurfacing technique that acts by creating small zones of thermal damage named 'microthermal zones'.^[132,133] This results in epidermal necrosis followed by collagen synthesis.^{[102,112,132,134]}

Other techniques. Other techniques reported in the literature include percutaneous collagen induction therapy and needling therapy ( Table 8 ). There are no widely accepted surgical procedures used in the treatment of SD.

1 2 3 4

Next Section

Table 1. Levels of evidence (LOE).
LOE-1	Systematic review with homogeneity of RCTs
LOE-2	Systematic review with homogeneity of cohort studies
	RCT
	Cohort study
	'Outcomes' research; ecological studies
LOE-3	Systematic review with homogeneity of case–control studies
	Nonrandomized controlled trial
	Individual case–control study
LOE-4	Case series
LOE-4	Comparative study
LOE-5	Case reports
LOE-5	Expert opinion without critical appraisal/based on physiology/bench research or 'first principles'

RCT, randomized controlled trial. Adapted from Oxford Centre of Evidence-Based Medicine.²¹

Table 2. Comparison of striae distensae among different patient population groups. ^{2-8,10,15,20,24-29}
Patient group	Location (most common to least common)	Proposed mechanism of formation	Average age (years)	Approximate prevalence (%)
Adult pregnant women	Abdomen, breasts, thighs	Stretch due to increased abdominal girth, adrenal cortical hyperactivity	23–27	43–88
Adult nonpregnant women	Breasts and thighs	Postpregnancy	29	35
Adolescent females	Thighs, buttocks, breasts	Stretching of the skin during growth spurt, adrenocortical hyperactivity	13–14	72–77
Adolescent males	Buttocks, thighs, calves, back	Stretching of the skin during growth spurt, adrenocortical hyperactivity	14	6–86
Adult males	Buttocks	Sudden weight gain/loss, muscular exercise	ND	11

ND, No data in the literature.

Table 3. Constitutional and pregnancy-related factors associated with striae distensae.
Factor	Davey (1972)⁹	Murphy et al. (1992)²⁸	Chang et al. (2004)⁶	Thomas and Liston (2004)⁵	Atwal et al. (2006)²⁰	Osman et al. (2007)⁸	Ghasemi et al. (2007)⁷	Maia et al. (2009)²⁵	Canpolat et al. (2010)²⁴
Constitutional
Maternal age		+		+		+		+	+
Maternal BMI		+		+	+		+		+
Maternal weight	+
Thickness of abdominal skin fold	+
Positive family history			+						+
Smoker								+
Use of cream	+
Pregnancy related
Birthweight	+	+				+	+	+	+
Gestational age									+
Weight gained during pregnancy					+	+		+
Polyhydramnios									+

BMI, body mass index; +, statistically significant.

Table 4. Medical conditions, surgery, medications and other factors linked with striae distensae. ^{2,9,13,14,33-52}
Associations with striae distensae
Medical conditions
Marfan syndrome, Cushing syndrome, anorexia nervosa, typhoid fever, rheumatic fever, chronic liver disease, obesity
Surgery
Augmentation mammoplasty, tissue expanded skin, tension-requiring skin sutures, organ transplantation, cardiac surgery
Medications
Systemic and topical corticosteroids, HIV therapy, chemotherapy, tuberculosis therapy, contraceptives, neuroleptics
Other
Pregnancy, puberty, stretch and weight training, idiopathic

HIV, human immunodeficiency virus.

Table 5. Histological comparisons of striae rubrae and striae albae ^{17,18,64–67}
	Striae rubrae	Striae albae
Clinical appearance	Raised pink linear lesions	Pale, depressed and finely wrinkled lesions; appear similar to scars
Epidermis	Oedema between melanocytes and keratinocytes; increased melanogenesis	Epidermal atrophy, loss of rete ridges and absent hair follicles; reduction in melanocytes leading to leucoderma
Papillary dermis	Vascular ectasia and possible angiogenesis	Lack of vascular stimulation
Reticular dermis	Collagen fibres structurally altered; elastic fibres reduced and reorganized; fine elastic fibres predominate throughout dermis with thick, tortuous fibres toward the periphery; reduced fibrillin microfibrils at the dermal–epidermal junction	Densely packed collagen parallel to skin surface; predominantly thick elastic fibres in dermis with normal appearance in periphery
Inflammatory cells	Dermal oedema, cuffing of the small vessels by lymphocytes, absent mast cells and prominent fibroblasts; increased glycosaminoglycan content	Eosinophils predominate among collagen fibres

Table 6. Visual and imaging techniques used to assess type, severity and efficacy of treatments of striae distensae (SD). ^{7,9,20,64,65,74-78}
Method	Type of striae	Explanation of method
Davey method	Striae rubrae and albae	Abdominal SD. Abdomen divided into quadrants using midline vertical and horizontal lines through umbilicus as divisions. Each quadrant given a score (0, no SD; 1, moderate number of SD; 2, many SD). Score is given out of 8
Atwal score	Striae rubrae and albae	Maximum score of six for each site (abdomen, hips, breasts, thigh/buttocks). Score 0–3 for presence of striae (0, no SD; 1, < 5 SD; 2, 5–10 SD; 3, > 10 SD); score 0–3 for presence of erythema (0, no erythema; 1, light red/pink; 2, dark red; 3, purple). Score out of 24
Dermoscopy	Striae rubrae, caerulae, nigrae and albae	Visualization of melanin networks and distinction of different types of striae due to the differences in melanin pigmentation: striae rubrae demonstrate a hypermelanosis while striae albae demonstrate leucoderma secondary to reduced melanocytes
Epiluminenscence colorimetry	Striae rubrae, caerulae, nigrae and albae	Computer device that measures colour from observer-defined small areas in photographs
Reflectance confocal microscopy	Striae rubrae and albae	Used in vivo. Low-power infrared laser reflects light from a single in-focus plane at different levels of depth in the skin. Readily visualizes the collagen and elastic fibre architecture and may be used to monitor treatment efficacy. SD appear more anisotropic and have greater skin roughness than adjacent skin. Not useful in evaluating inflammatory changes in striae formation
Primos 3D camera	Striae rubrae and albae	Reflected light absorbed by a high-resolution camera that records height differences from which a 3D image is produced. 3D image demonstrates the skin-surface topography including the depth, distribution and variation of skin furrows

Table 7. Summary and levels of evidence for topical treatments used in the treatment of striae distensae (SD).
Author	Treatment evaluated	Form of treatment	Striae type	Dosage	No. of subjects (T/C)	Outcome	Adverse effects	Study design	Level of evidence
Kang et al.[12, 80]	Tretinoin vs. placebo	Therapeutic	Rubrae	0·1% daily, 6 months	22 (10/12)	80% (n = 8) of tretinoin-treated patients had definite marked improvement, compared with 8% (n = 1) in control group. Reduced length and width of striae by 14% and 8%, respectively, compared with increased length and width in control by 10% and 24%, respectively. No significant difference in dermal collagen and elastic fibres in treatment compared with placebo	Erythema or scaling first 2 months (55%)	RCT	2
Rangel et al.⁸¹	Tretinoin	Therapeutic	Not stated	0·1% daily, 3 months	20	Reduction in length of stretch marks by up to 20%. Significant global improvement from baseline noted in all stretch marks. Half of the abdomen was treated and the other half acted as the control. No randomization in this study	Erythema or scaling in first month (55%)	Nonrandomized controlled trial	3
Mallol et al.⁷³	Trofolastin (Centella asiatica ) vs. placebo	Prophylaxis	Not stated	Daily, 12th week pregnancy until labour	80 (41/39)	Results demonstrated that 56% in placebo and 34% in treated group developed striae. The arbitrary score (from 0–3) for intensity was 1·42 for the treated group and 2·13 for the placebo group. In women with a history of SD during puberty, the treatment cream gave a significant absolute prevention of SD of 89%	None stated	RCT	2
Ud-Din et al.⁸²	Silicone vs. placebo either side of abdomen	Therapeutic	Not stated	Daily for 6 weeks	20	Results demonstrated increased melanin, with decreased haemoglobin, collagen and pliability on both sides. Collagen levels were significantly higher and melanin lower with silicone gel compared with controls	None stated	RCT	2
Draelos et al.⁸³	Centella asiatica/hyaluronic acid	Therapeutic	Rubrae	Twice daily, 12 weeks	52	Statistically significant difference in participant and investigator evaluations of overall appearance, colour, softness and texture between treatment and control groups. Patient's untreated thigh acted as control. No placebo used	None stated	RCT	2
Wierrani et al.⁸⁴	Verum® (hyaluronic acid)	Prophylaxis	Not stated	Unknown	50 (24/26)	One-third of women with prophylactic treatment developed SD compared with two-thirds in the control group. Better results in those women that were not overweight. Unclear risk of attrition and performance bias	None stated	RCT	2
de Buman et al.⁸⁵	Alphastria® vs. placebo	Prophylaxis	Not stated	Unknown	90 (30/30/30)	Three groups: A = Alphastria cream, B = cream with excipients and vitamins, C = placebo with just excipient. 10% in prophylactically treated compared with 70% in placebo treated developed striae	None stated	RCT	2
Osman et al.⁸⁶	Cocoa butter vs. placebo	Prophylaxis	Not stated	Daily, 12–18 weeks' gestation until delivery	175 (91/84)	No significant difference in development of SD between treatment and placebo groups	None stated	RCT	2
Buchanan et al.¹⁹	Cocoa butter vs. placebo	Prophylaxis	Not stated	Daily, 12–15 weeks' gestation until delivery	300 (150/150)	No significant difference in development of striae between treatment and placebo groups	None stated	RCT	2
Taavoni et al.⁸⁷	Olive oil	Prophylaxis	Not stated	Twice daily, 18–20 weeks' gestation, for 8 weeks	70 (35/35)	Subjects randomized into control or intervention group. Intervention group applied olive oil and control group underwent no intervention. No significant difference in development of SD between treatment and control groups. No placebo used for control group	None stated	RCT	2
Timur and Kafkasli⁸⁸	Almond oil with massage vs. almond oil alone vs. control	Prophylaxis	Not stated	Cream every other day, 19th–32nd week gestation	141 (47/48/46)	Significant difference in frequency of SD between groups: almond oil and massage 20%, almond oil alone 38·8%, control 41·2%	None stated	Nonrandomized controlled trial	3
Mendez et al.⁸⁹	Hydrant cream wet skin vs. hydrant cream dry skin	Prophylaxis	Not stated	Daily, 16–18 weeks' gestation until delivery	50	Percentage of women without SD was 57% when cream applied on wet skin compared with 44% when applied to dry skin. Skin on the patients forearm acted as a control.	None stated	RCT	2
Ash et al.⁹⁰	20% glycolic acid/10% ascorbic acid/2% zinc sulfate/0·5% tyrosine vs. 20% glycolic acid/0·05% tretinoin. Applied onto SD on abdomen or thighs with area split into halves	Therapeutic	Albae	Daily, 12 weeks	10	Both regimens improved appearance of SD. They both increased epidermal thickness and decreased papillary dermal thickness. Increased elastin content with topical 20% glycolic acid and 0·05% tretinoin. No control group	Hyperpigmentation	Comparative study	4
Adatto and Deprez⁹¹	Sand abrasion and 15% TCA then post-peel cream	Therapeutic	All types	1–8 treatments (mean 4·2)	69	Average improvement of 70% on all types of striae and locations. Results better in striae rubrae.	PIH at 4 weeks especially in darker skin	Case series	4
Deprez⁹²	TCA then post-peel cream	Therapeutic	Not stated	50% TCA, up to eight treatments	50	Striae reduced in depth. Almost all patients had 60–75% improvement at end of treatment No control and no randomization in this study	Erythema and hyperpigmentation	Case series	4
Mazzarello et al.⁹³	Group A (striae rubrae) = 70% glycolic acid vs. placebo. Group B (striae albae) = 70% glycolic acid vs. placebo	Therapeutic	All types	Six treatments over 6 months	40	Decrease in furrow width of striae in both groups. Striae rubrae showed decrease in haemoglobin and striae albae an increase in melanin. Patient's other thigh acted as control	None stated	Nonrandomized controlled trial	3
Total studies: 16	LOE-1: 0; LOE-2: 10; LOE-3: 3; LOE-4: 3

C, control; PIH, postinflammatory hyperpigmentation; RCT, randomized controlled trial; T, treatment; TCA, trichloroacetic acid.

Table 8. Summary and levels of evidence for laser, light and miscellaneous therapies used to treat striae distensae (SD). ¹²⁹
Author	Device evaluated	Striae type	Fitzpatrick skin type	Wavelength and regimen	No. of subjects (T/C)	Outcome	Adverse effects	Study design	Level of evidence
McDaniel et al.¹⁰⁶	PDL	Albae 38, rubrae 1	Not stated	585-nm. Four protocols (spot diameter, fluence): 1 = 10 mm, 2·5 J cm⁻²; 2 = 10 mm, 3·0 J cm⁻²; 3 = 7 mm, 2·0 J cm⁻²; 4 = 7 mm, 4·0 J cm⁻²	39	The 10-mm spot size with 3·0 J cm⁻² improved the SD better than other treatment protocols. Significant reduction in skin shadowing in SD with all protocols (shadow profilometry). Normal-appearing elastin in SD treated with low-fluence PDL	Mild transient purpura or slight erythema	Nonrandomized controlled trial	3
Jimenez et al.¹¹³	PDL	Albae 11, rubrae 9	II–IV	585-nm, two treatments at baseline and at week 6	20	No significant difference between control and treated SD after 12 weeks.13/20 and 9/20 subjects had decreased area of striae in treated and nontreated areas, respectively. None of the striae albae had a change in colour. Four of nine striae rubrae showed improvement	PIH in one patient	Nonrandomized controlled trial	3
Nehal et al.¹¹⁴	PDL	Albae	Not stated	585-nm, 10 mm spot size and fluence of 4·25 J cm⁻². Treated at 2-month intervals for 1–2 years	5	Subjectively reported slightly improved appearance of SD. No pre- or post-treatment photographic improvement. Histologically no significant changes reported following treatment	PIH in darker skin types	Case series	4
Suh et al.¹⁰⁵	PDL/RF	Albae 36, rubrae 1	III–IV	585-nm, three treatments at baseline, Thermage RF device used with fluences 53–97 J cm⁻² (dial setting 10·5–13·5) with 2–3 passes. (PDL/RF), week 4 (PDL), week 8 (PDL)	37	Subjective assessment showed 89% of patients had 'good and very good' overall improvement in SD while 59% in were graded 'good and very good' in elasticity. No control and no randomization in this study	Transient purpura (16%) and PIH (3%)	Case series	4
Goldman et al.³⁶	Nd:YAG laser	Rubrae	II–IV	1064-nm, average number of treatment sessions was 3·45 with an interval of 3–6 weeks	20	Results considered as excellent by 55% and 40% of patients and doctors, respectively. No control and no randomization in this study	Minimal oedema and erythema	Case series	4
Tay et al.¹⁰⁷	Nonablative diode laser	Albae 9, rubrae 2	IV–VI	1450-nm, three treatments at 6-week intervals	11	No patients showed any noticeable improvement compared with control areas (one side of the body was treated with other side acting as control). Not all outcomes are reported in the results	Transient erythema, PIH (64%, n = 7)	RCT	2
de Angelis et al.³²	Er:glass fractional nonablative laser	All types	II–IV	1540-nm, 2–3 passes, 2–4 total treatments at 6-week intervals	51	50% or greater overall improvement at 6 months (unblinded assessment), 51–75% improvement (blinded assessment). No control in this study	Transient oedema, erythema, PIH	Case series	4
Stotland et al.¹¹⁵	Er:glass fractional nonablative laser	Albae 13, rubrae 1	I–IV	1550-nm, 8–12 passes with fluences of 12–18 J cm⁻², six treatments in total	14	Overall improvement of 26–50% in 63% of patients (n = 5), < 25% improvement in dyschromia in 50% of patients (n = 4), improved texture of 26–50% in 50% of patients (n = 4). Untreated striae acted as controls.	Post-treatment oedema, erythema and papules	RCT	2
Guimarães et al.¹¹⁶	Er:glass fractional nonablative laser	Rubrae	Not stated	1540-nm, eight sessions in total	10	Post-breast augmentation SD. Three patients completed eight treatments. One month after the last treatment, all patients showed a marked improvement in the striae. No controls or randomization	Post-laser erythema, PIH in 10% (n = 1)	Case series	4
Yang and Lee¹¹⁷	Er:glass fractional nonablative laser vs. ablative fractional CO₂ laser	Albae	IV	Er:glass 1550-nm at a pulse of 50 mJ and spot density 100 spots cm⁻². CO₂ pulse energy 40–50 mJ and spot density 75–100 spots cm⁻². Three treatments at 4-week intervals	22	Abdomen split into two halves and each half randomized to one of the two treatments. No statistical difference between the two lasers but significant clinical and histological improvement comparing pre- and post-treatment. No control used	PIH (36%)	Comparative study	4
Goldberg et al.¹¹⁰	XeCl excimer UVB laser vs. UVB light device	Albae	II–IV	Up to 10 treatments, XeCl 308-nm, UVB 290–320-nm	10	Increased melanin, hypertrophy and increased number of melanocytes in all treated SD. Maintained at 6 months. No control and no randomization in this study	Not stated	Comparative study	4
Goldberg et al.¹¹⁸	XeCl excimer laser	Albae	II–IV	308-nm, treatments continued until 15 completed or > 75% increase in pigmentation	75	Clinically evident improvement in striae reported in 80% of subjects. Average of 8·4 treatments. For the first 10 patients, half the area of trunk/extremity acted as a control. In the remaining 65, both sides were treated	Erythema (100%)	Case series	4
Ostovari et al.¹¹⁹	XeCl excimer laser	Albae	I–IV	308-nm, weekly until 10 treatments completed or until 100% repigmentation	10	80% of patients had a poor or moderate result based on photographs and 70% based on patients' self-assessment.	PIH	Nonrandomized controlled trial	3
Alexiades-Armenakas et al.¹²⁰	XeCl excimer laser	Albae	Not stated	308-nm, every 2 weeks until maximum of 10 treatments, 75% or 100% increase in colorimetric or visual pigment correction, respectively	9	68% improvement in mean pigmentation relative to normal skin control. Mean percentage pigmentation 102% compared with control. Overall excellent pigment correction maintained to 2 months follow-up	Transient erythema	RCT	2
Longo et al.¹⁰⁴	Copper bromide laser	Not stated	II–III	577-nm, 1–5 sessions 1 month apart	15	Five out of 15 subjects experienced complete disappearance of striae, other subjects: 50–90% improvement of dimensions. In 13/15 results were maintained after 1 year. No control and no randomization in this study	Erythema	Case Series	4
Al-Dhalimi and Abo Nasyria¹²¹	IPL 650-nm vs. 590-nm	Rubrae	III–IV	Two cut-off filters used 590-nm on left and 650-nm on right, starting fluence 13 J cm⁻² increased to 15·5 J cm⁻². Five sessions at 2-week intervals	20	Significant reduction in total number of SD on right from 256 to 240. Significant reduction in SD on left from 251 to 228. Also decreased sum of lengths and maximum widths. No control and no randomization in this study	Severe erythema (60%, n = 6)	Comparative study	4
Hernández-Pérez et al.¹⁰⁰	IPL	Albae	80% IV, 20% III	515–1200-nm, five sessions once every 2 weeks	15	Sum of the total length of striae reduced from 375to 239 cm. Reduced number of striae from a total of 117 to 94. Significant difference in post-treatment dermal thickness. No control and no randomization in this study	PIH (40%)	Case Series	4
Sadick et al.¹⁰⁸	UVA/UVB light therapy (Multiclear^TM)	Albae	II–IV	UVB 296–315-nm, UVA1 360–370-nm, twice weekly for maximum of 10 treatments	9	Five subjects had completely repigmented striae, three had 76–100% improvement and one had 51–75% improvement. Improvement only short term. No randomization in this study	PIH (> 50%)	Nonrandomized controlled trial	3
Trelles et al.¹⁰⁹	Infrared light system (NovaPlus)	Albae	II–IV	Three passes per session over four sessions, 15 days apart	10	Four patients reported results as 'fair', two as 'better' and four as 'same'. 3D optical skin imaging showed improvement of 25–50% in depth corresponding to SD. Histology showed improvements compared with specimens at baseline. No control and no randomization in this study	Minimal erythema for 24 h	Case series	4
Manuskiatti et al.¹¹¹	RF device	Albae 16, rubrae 1	IV–V	Six, weekly treatments. TriPollar RF device (3 electrodes) used at range of 40–50 W and frequency range 1 MHz	17	38% and 12% of subjects had 25–50% and 51–75% improvement in striae, respectively, on assessment. 12%, 23% and 65% of subjects rated their contentment as slightly satisfied, satisfied and very satisfied, respectively. No control and no randomization in this study	None reported	Case series	4
Suh et al.¹²²	Plasma fractional RF and platelet-rich plasma and ultrasound	Not stated	III–V	Fortnightly for total of four sessions	18	Two blinded reviewers rated 'excellent' results (75–100% improvement) in 33% (n = 6) of subjects, 'very good' (50–74% improvement) in 38·9% (n = 7), 'good' (25–49% improvement) in 22·4% (n = 4) and 'mild' (1–24% improvement) in 5·6% (n = 1). No control and no randomization in this study	PIH (11%)	Case series	4
Kim et al.¹²³	Intradermal RF and autologous platelet-rich plasma	Not stated	IV	Three sessions once every 4 weeks, RF device frequency of 1134 kHz	19	Objective assessment demonstrated 5% of patients with excellent improvement (n = 1), 37% with marked improvement (n = 7), 32% with moderate improvement (n = 6) and 26% with mild improvement (n = 5). No control and no randomization in this study	Transient bruising lasting 3–7 days (100%)	Case series	4
Ryu et al.¹²⁴	Fractionated microneedle RF vs. fractional CO₂ laser	Not stated	IV	Three treatment groups: fractional CO₂ laser (n = 10), microneedle RF (n = 10), and both (n = 10)	30	Improvement evaluated on a visual analogue scale 1–4 (1 = minimal improvement or steady state, 4 = near total improvement), was 2·2 in the fractional CO₂ laser-treated group, 1·8 in the microneedle RF-treated group and 3·4 in the combination group. A thickened epidermis and increase in collagen fibres observed in the combination-treated sites. No control and no randomization in this study	Transient PIH, pain and pruritus	Comparative study	4
Lee et al.⁷⁹	Short-pulsed CO₂ laser	Albae	IV	10 600-nm	27	Results showed that 7% (n = 2) had > 75% improvement, 52% (n = 14) had 51–75% improvement, 33% (n = 9) had 26–50% improvement and 7% (n = 2) had 0–25% improvement. No control and no randomization in this study	Short-term erythema (100%) 4 weeks and mild PIH resolving within 4 weeks	Case series	4
Nouri et al.¹²⁵	Short-pulsed CO₂ laser vs. control vs. PDL	Not stated	IV–VI	CO₂ 10 600-nm, two passes then saline wash. PDL 585-nm	4	At 20-week follow-up, type IV skin showed no improvement with PDL, type VI showed hyperpigmentation. The short pulsed CO₂ showed persistent erythema and marked hyperpigmentation in types IV and VI skin respectively	Persistent erythema and PIH in skin types IV and VI with CO₂ laser	Nonrandomized controlled trial	3
Bak et al.¹¹²	Fractional photothermolysis (Fraxel SR 1500)	Rubrae 16, albae 6	Not stated	1500-nm, two sessions of eight passes at 4-week intervals	22	27% (n = 6) of patients showed marked improvement of SD while 63% (n = 16) showed mild improvement. Significant increase in average epidermal and dermal thickness from baseline. No control and no randomization in this study	Erythema, mild pigmentation, PIH (9%)	Case series	4
Abdel-Latif and Albendary¹⁰³	Microdermabrasion	Rubrae 12, albae 8	II–IV	Five treatments at weekly intervals	20	Other half of body acted as control. 'Good to excellent' improvement in striae in 50% of subjects. Remaining 50% had 'mild to moderate' improvement. Most improvement in striae rubrae. Significantly increased type I procollagen α1 mRNA in treatment compared with controls. No randomization	Transient erythema (25%, n = 5) and PIH (20%, n = 4)	Nonrandomized controlled trial	3
Shin et al.¹²⁶	Group A (3 areas) = laser/laser and collagen/collagen. Group B (3 areas) = laser/laser and placebo/placebo	Albae	III–IV	Succinylated atelocollagen and ablative fractional resurfacing laser, three laser treatments at 4-week intervals	12	Clinical improvement scores evaluated by two doctors found a significant difference between atelocollagen and placebo sites after laser treatment and also between atelocollagen and placebo. No randomization	Erythema (100%) for 2–3 days, PIH (75%), one patient developed psoriasis	Nonrandomized controlled trial	3
Aust et al.¹²⁷	Percutaneous collagen induction therapy	Not stated	Not stated	Single 30-min procedure	22	At 6 months follow-up improved skin texture, skin tightening, dermal neovascularization and no change in pigmentation. Increased collagen I and elastin on biopsy. No control and no randomization in this study	None reported	Case series	4
Park et al.¹²⁸	Needling therapy	Albae 11, rubrae 5	III–IV	Three treatments at 4-week intervals	16	Results reported were that 37% (n = 6) of patients were highly satisfied, 50% (n = 8) were somewhat satisfied and 13% (n = 2) were unsatisfied. Increased collagen was found in the dermis post-treatment and the fragmented dermal elastin fibres normalized post-treatment. No control and no randomization in this study	Pain, erythema, spotty bleeding and pruritus	Case series	4
Total studies: 30	LOE-1: 0; LOE-2: 3; LOE-3: 7; LOE-4: 20

Er, erbium; IPL, intense pulsed light; Nd:YAG, neodymium-doped YAG; PDL, pulsed-dye laser; PIH, postinflammatory hyperpigmentation; RCT, randomized controlled trial; RF, radiofrequency; UV, ultraviolet.