Contractile forces generated by striae distensae fibroblasts embedded in collagen lattices

Striae distensae are characterized by linear, smooth bands of atrophic-appearing skin that are reddish at first and finally white. They are due to stretching of the skin, as in rapid weight gain, or mechanical stress, as in weight lifting. The pathogenesis of striae distensae is unknown but probably relates to changes in the fibroblast phenotype. In order to characterize striae distensae fibroblasts, alpha-smooth muscle actin expression and contractile forces were studied. Five healthy women with early erythematous striae and five healthy women with older striae were selected. Paired biopsies were taken from the center of lesional striae and adjacent normal skin. Fibroblasts were obtained by an explant technique and expanded in vitro in Dulbecco’s modified Eagle‘s medium. Contractile forces generated by fibroblasts in collagen lattices were measured with the Glasbox device developed in our laboratory. Alpha-smooth muscle actin expression was studied by immunofluorescence labeling of cells and by flow cytometry. Fibroblasts from early striae distensae were the richest cells in alpha-smooth muscle actin filaments and generated the highest contractile forces. Their peak contractile force was 26% greater than normal fibroblasts. There was a 150% higher level of alpha-smooth muscle actin content in fibroblasts from early striae distensae compared with fibroblasts from normal skin. In contrast, there was no significant difference in force generation between old striae fibroblasts and normal fibroblasts with cells expressing no alpha-smooth muscle actin. The contractile properties of fibroblasts from striae distensae varies depending on the stage of the disease. In early striae distensae, fibroblasts acquire a more contractile phenotype, corresponding to that of myofibroblasts.     

Treatment of striae distensae combined enhanced penetration platelet-rich plasma and ultrasound after plasma fractional radiofrequency

Abstract

Background: Striae distensae (striae alba) is a challenging cosmetic problem for which various treatment modalities have been applied. However, the treatment of striae distensae has not been satisfactory. Objectives: This study was done to evaluate the effectiveness and the safety of enhanced penetration of platelet rich plasma with ultrasound after plasma fractional radiofrequency for the treatment of striae distensae. Subjects and method: Eighteen participants with striae distensae were treated with a Legato system (Alma Lasers, Israel) every two weeks for a total of four sessions. Thereafter, in order to enhance platelet-rich plasma penetration, ultrasound is applied. Clinical photographs were taken before first treatment and two months after the final treatment. Objective and subjective improvement scores were evaluated to demonstrate the efficacy. Abdominal skin biopsies were obtained from three individuals and histological changes were analyzed by light microscopy. Results: During the two months after the last treatment, the average width of the widest striae had decreased from 0.75 to 0.27 mm. In the objective assessment, 71.9% of the participants reported ‘‘good” or “very good’’ overall improvement. In the subjective assessment, and 72.2% of the participants reported ‘‘very satisfied” or “extremely satisfied’’ with overall improvement. The only reported side effect was post-inflammatory hyperpigmentation (11.1%). Conclusions: The plasma fractional radiofrequency and transepidermal delivery of platelet-rich plasma using ultrasound is useful in the treatment of striae distensae.     

High-resolution epiluminescence colorimetry of striae distensae

BACKGROUND: Colours of striae distensae are often different from that of the surrounding skin. A close look using dermoscopy discloses distinct patterns of melanized networks at these sites. The aim of the study was to design a method of high-\resolution analytical analysis of the skin colours using the combination of photographic dermoscopy and small field reflectance colorimetry. METHODS: Clinical photographs were taken from striae distensae and their surrounding skin using a Dermaphot (Heine Optotechnik, Hersching, Germany). A final magnification of 125x was obtained on paper photographs. The reflectance colorimeter Visi-Chroma VC-100 (Biophotonics, Lessines, Belgium) was used to measure colours of the pigmentary networks in the L*a*b* system. Differential colour parameters (deltaE*ab, deltaL*, deltaa*, deltab*) were calculated for each case between the lesional and the surrounding normal skin, and between the melanized reticulated pattern and the enclosed lighter areas. RESULTS: Objective colorimetric assessments distinguished four distinct types, namely striae albae, striae rubrae, striae caeruleae and striae nigrae. The latter peculiar hyperpigmented type of striae distensae was specifically identified by epiluminescence examination in dark-skinned subjects. The fine-melanized honeycomb network present on the adjacent intact skin was reshaped inside striae in a streaky pattern perpendicular to the striae axis. Strong linear correlations were found between all combinations of deltaL* and deltab* evaluating colours of the reticulated and the honeycomb alveolar patterns both inside and outside the striae distensae. By contrast, no correlations were found between deltaa* and the other colorimetric parameters. CONCLUSION: The direct and/or indirect influences of melanocyte mechanobiology appear to have a prominent effect on the various colours of striae distensae.     

Treatment of striae distensae using fractional ablative CO2 laser in skin types II-IV: a retrospective case series study

Striae distensae (SD) are atrophic dermal scars often found on abdomen, breasts, thighs, and hips of pregnant women. The strias’ self-healing without any intervention is a poor possibility. Till now, several lasers and light sources have been used for treatment of SD. However, there are no integrated therapeutic approaches determined for treatment of SD yet. So, in this study, the therapeutic effect of fractional ablative CO₂ laser in women with pregnancy was assessed. Twenty-four ethic Iranian women aged between 20 and 42 years with various severity of pregnancy SD enrolled in retrospective case series study. Participants with skin types II-IV were treated in four sessions with a one-month interval by fractional ablative CO₂ laser. The severity of striae was determined by Daveys scoring. Clinical improvement was assessed by comparing pretreatment and posttreatment clinical photographs based on global improvement scoring. The evaluation of clinical results showed that fractional ablative CO₂ laser was an effective treatment. Twenty of 24 (83.3%) patients showed improvement. Clinical improvement was affected by striae severity (P = 0.03). Also, there were no statistical differences between clinical improvements with skin types, striae scar severity, number of pregnancy, and striae location.     

Decreased expression of collagen and fibronectin genes in striae distensae tissue

Striae distensae are characterized by a thinning of connective tissue stroma to produce linear, atrophic-appearing skin. Excessive adrenocortical activity, genetic factors and inherited defects of connective tissues, etc. are important causative factors in the formation of striae distensae, but the basic aetiology is not known. Total RNA was extracted from skin biopsies of five patients with striae distensae. The expression of genes coding for types I and III procollagen, elastin, fibronectin and β-actin were studied and compared with those of four sex- and age-matched healthy individuals. The percentages of types I and III procollagen mRNA were 9.9 ± 2.9% (mean ± s.d.) and 10.6 ± 1.6%, respectively, of the corresponding controls. The value for fibronectin mRNA in striae distensae was 7.3 ± 1.8% of the control. The steady-state ratio fibronectin/type I procollagen mRNAs was 0.12 ± 0.01 in striae distensae and (MS ± 0.01 in the control. These observations suggest that expression of collagens, elastin and fibronectin genes are apparently decreased, and that there is a marked alteration of fibroblast metabolism, in striae distensae.     

Fibrillin microfibrils are reduced in skin exhibiting striae distensae

Striae distensae (striae: stretch marks) are a common disfiguring condition associated with continuous and progressive stretching of the skin—as occurs during pregnancy. The pathogenesis of striae is unknown but probably relates to changes in those structures that provide skin with its tensile strength and elasticity. Such structures are components of the extracellular matrix, including fibrillin, elastin and collagens. Using a variety of histological techniques, we assessed the distribution of these extracellular matrix components in skin affected by striae. Pregnant women were assessed for the presence of striae, and punch biopsies were obtained from lesional striae and adjacent normal skin. Biopsies were processed for electron microscopy, light microscopy and immunohistochemistry. For histological examination, 7 μm frozen sections were stained so as to identify the elastic fibre network and glycosaminoglycans. Biopsies were also examined with a panel of polyclonal antibodies against collagens I and III, and fibrillin and elastin. Ultrastructural analysis revealed alterations in the appearance of skin affected by striae compared with that of normal skin in that the dermal matrix of striae was looser and more floccular. Light microscopy revealed an increase in glycosaminoglycan content in striae. Furthermore, the number of vertical fibrillin fibres subjacent to the dermal–epidermal junction (DEJ) and elastin fibres in the papillary dermis was significantly reduced in striae compared with normal skin. The orientation of elastin and fibrillin fibres in the deep dermis showed realignment in that the fibres ran parallel to the DEJ. However, no significant alterations were observed in any other extracellular matrix components. This study identifies a reorganization and diminution of the elastic fibre network of skin affected by striae. Continuous strain on the dermal extracellular matrix, as occurs during pregnancy, may remodel the elastic fibre network in susceptible individuals and manifest clinically as striae distensae.     

Striae distensae in darker skin types: the influence of melanocyte mechanobiology

Introduction Striae distensae in White people are commonly described as being reddish at first and turning white in time. This dual perception has been challenged. Indeed, the color difference between striae distensae and their surrounding skin varies on a wide range in part depending upon typology. Aim To study striae nigrae that are found only in subjects of darker complexion. Materials and methods In the present study conducted in 44 darker skin adults, dermoscopy was combined to reflectance colorimetry. Results Striae nigrae exhibited hypermelanosis of the epidermal rete ridges crossing transversally the lesions in a laddering pattern. By contrast, striae albae showed only faint melanotic networks. Conclusions As striae distensae are in part under the influence of skin stretching, their colors are likely to be controlled by some mechanobiological process activating or inhibiting melanogenesis in people of darker complexion. No argument involving an inflammatory mechanism is supported by the present observations.     

Unilateral Striae Distensae Affecting the Right Axilla in a 16‐Year‐Old Boy: Brief Report

Striae distensae or stretch marks are a common skin condition that occurs frequently in association with adolescent growth spurts and pregnancy. They are characterized by linear symmetrical asymptomatic smooth bands of atrophic‐appearing skin on the thighs, buttocks, and breasts in girls and on the shoulders, outer thighs, and lumbosacral areas in boys. We present a rare case of unilateral striae distensae affecting the right axilla in a 16‐year‐old boy.     

Clinical features and risk factors for striae distensae in Korean adolescents

BACKGROUND: Despite the high prevalence of striae distensae, clinical studies are few in number, and their pathophysiology still obscure. OBJECTIVES: To determine the prevalence and clinical characteristics of striae distensae that occur in Korean adolescents, and to correlate their clinical features with family history, other dermatological conditions, and body measurements. METHODS: One hundred and fifty-seven healthy Korean students, aged 15 to 17, were studied. A questionnaire and physical examination were employed to assess the subjects' past and family history, and the distribution, clinical features and severity of striae distensae. RESULTS: Striae distensae were present in 131 subjects (83.4%). Ninety-four (88.2%) of 109 male and 37 (77.1%) of 48 female subjects were affected. The striae were white in colour in 69.5% and asymptomatic in most of the subjects. They developed at an average age of 13.8 years. Family history was present in 18 subjects (11.5%). Seborrhoea of the face was positively correlated (P < 0.035) with striae distensae, and atopic dermatitis negatively correlated (P < 0.001). In both sexes, the buttock was the most prevalent area of striae development, followed by the lower back and knee in boys and by the thigh and calf in girls. Striae were significantly more common on the thigh of girls and on the knee of boys. CONCLUSIONS: Our results indicate that striae distensae are a common skin condition that occurs early in puberty regardless of gender, and that they have a different anatomical distribution and relationship with body measurements in each gender.     

Treatment of Striae Distensae with Nonablative Fractional Laser versus Ablative CO2 Fractional Laser: A Randomized Controlled Trial

Background

Striae distensae are atrophic dermal scars with overlying epidermal atrophy causing significant cosmetic concern. Although a variety of laser and light sources have been used for the treatment of striae distensae, to date no definite ''gold standard'' treatment modality has been determined.

Objective

To assess and compare the efficacy and safety of nonablative fractional photothermolysis and ablative CO₂ fractional laser resurfacing in the treatment of striae distensae.

Methods

Twenty-four ethnic South Korean patients with varying degrees of atrophic striae alba in the abdomen were enrolled in a randomized blind split study. The patients were treated with 1,550 nm fractional Er:Glass laser and ablative fractional CO₂ laser resurfacing. Each half of the abdominal lesion was randomly selected and treated three times at intervals of 4-weeks using the same parameters. Digital photography was conducted and skin elasticity and the width of the widest striae in each subject were measured at the baseline and 4 weeks after the final treatment. Clinical improvement was assessed by comparing pre- and post-treatment clinical photographs by two blinded physicians and participant satisfaction rates were evaluated. Skin biopsies were taken from three participants. All adverse effects were reported during the study.

Results

Although they do not statistically differ, both treatments with nonablative fractional laser and ablative CO₂ fractional laser showed a significant clinical and histopathologic improvement of striae distensae over pretreatment sites.

Conclusion

These results support the use of nonablative fractional laser and ablative CO₂ fractional laser as effective and safe treatment modalities for striae distensae of Asian skin. However, neither treatment showed any greater clinical improvement than the other treatment.     

An investigation of striae distensae using reflectance confocal microscopy

Background: Striae distensae, otherwise known as stretch marks, are white or red scar‐like streaks on the skin. Although they are not associated with adverse health outcomes, striae are associated with significant cosmetic morbidity. While they have been well characterised histopathologically, a non‐invasive method of microscopic lesion assessment of striae would be welcome. Methods: To gain insight into the small‐scale morphological features associated with striae we undertook an in vivo investigation of nine patients with striae alba and one with striae rubra utilising reflectance confocal microscopy (RCM). Results: Here we demonstrate that features known to be present using light microscopy, such as parallel collagen bundles in the dermis, and some features that are not well recognised by light microscopy, including distortion of dermal papillae, are demonstrable using RCM. Conclusions: Characterising the features of early and established striae distensae with confocal microscopy is an important foundation for future work. The potential ability to reliably identify the earliest pathological changes in skin in early lesions or before clinically manifest striae develop – a task facilitated by our findings – will increase the understanding of their pathogenesis and will have significant practical utility in monitoring the impact of future preventative interventions.     

URTICARIAL VASCULITIS DEVELOPED ON THE STRIAE DISTENSAE DURING PREGNANCY

A 23-year-old woman (gravida 1, para 0) in her 34th week of pregnancy had urticarial erythema on the legs for a period of 2 weeks. The initial eruptions of erythematous papules, plaques, and urticarial lesions were noted on the calves, at the site of striae distensae. The number of erythematous le-sions had increased during the last 10 days to cover most of the preexisting sites of striae distensae on the lower legs and thighs, with several satellite lesions (Fig. 1). Individual lesions on the legs were pruritic and persisted longer than 1 day. The lesions of striae distensae on the legs (with urticari-al erythema) and on the abdomen (without any overlying urticarial lesions) had occurred during pregnancy over the past 8 months. There was no history of drug use, infection, or any other systemic disorders relevant to the skin dis-ease. Systemic symptoms such as fever, arthralgia, or malaise were not associated with the evolution of the ur-ticarial erythema. Her past medical history and family history were non-contributory. She was healthy and maintained uncomplicat-ed normal pregnancy without any remarkable findings on physical examination except for the skin lesions. A biopsy specimen taken from a satellite lesion showed a moderate degree of perivascular and transmural infiltra-tion of neutrophils, eosinophils, and lymphohistiocytic cells, with some nuclear dust in the upper dermis. Endothe-lial swellings and foci of extravasation of red blood cells were also seen (Fig. 2). The direct immunofluorescence study of the same tissue showed deposits of IgM and C3 in the blood vessel walls of the upper dermis (Fig. 2). The erythrocyte sedimentation rate was elevated to 45 mm/h. Complete blood count with differential, platelet count, urinalysis, and stool test for occult blood were within normal limits or negative. The pattern of serum protein electrophoresis, total serum hemolytic complement, and levels of human chorionic gonadotropin were all normal. The results of the tests for antinuciear antibodies, cryoglob-ulin, hepatitis B surface antigen, and VDRL were negative. The skin lesions of urticarial vasculitis in this patient were treated with oral prednisolone (25 mg/d). The pruritic lesions cleared in a week with no evidence of recurrence until the postpartum period.     

Fractional CO2 Laser Versus Intense Pulsed Light in Treating Striae Distensae

Context:Striae distensae are linear atrophic dermal scars covered with flat atrophic epidermis. They may cause disfigurement, especially in females. Many factors may cause striae distensae such as steroids, obesity, and pregnancy. Although there is no standard treatment for striae; many topical applications, peeling, and light and laser systems have been tried.Aims:To evaluate and compare the efficacy of fractional CO₂ laser with intense pulse light in treating striae distensae.Results:Both groups showed significant improvement after treatments (P < 0.05). Patients treated with fractional CO₂ laser showed significant improvement after the fifth session compared with those treated with ten sessions of intense pulsed light (P < 0.05) in all parameters except in the length of striae (P > 0.05).Conclusions:The current study has provided supportive evidence to the effectiveness of both fractional CO₂ laser and intense pulse light as treatments for striae distensae. Fractional CO₂ laser was found to be more effective in the treatment of striae distensae compared with intense pulse light.     

Striae distensae: a comprehensive review and evidence‐based evaluation of prophylaxis and treatment

Striae distensae are an extremely common, therapeutically challenging form of dermal scarring. Risk factors have been reported but much remains to be understood about their epidemiology, diagnosis and treatment. Up‐to‐date knowledge of the scientific research and the evidence behind both preventative and therapeutic agents are vital in order to understand striae and to offer patients the best therapeutic alternatives. We present a clinical review of the current literature concerning striae distensae and their prevention and treatment. A systematic review of the literature was undertaken using Medline, Embase and Google Scholar. Articles in English, Spanish, Portuguese, Turkish and French were included. Striae distensae occur in pregnancy, puberty and obesity as well as in numerous medical conditions and following therapeutic interventions. Proposed aetiological mechanisms relate to hormones, physical stretch and structural alterations to the integument. Assessment methods include subjective visual scoring and various imaging modalities. Treatments that we have evaluated include topical agents, used prophylactically or therapeutically, as well as light and laser therapies, which have shown improvements in the appearance of striae. Few high level evidence based medicine randomized controlled trials evaluating treatments for striae distensae exist. Topical therapeutic agents appear to lack efficacy in the prevention of striae distensae.     

Striae distensae after tension-requiring skin sutures

Three cases of striae distensae which developed along suture scars after skin surgery were described. The production of striae should be taken into consideration in surgery of the skin, especially in young woman.     

Embarazo y piel. Cambios fisiológicos y trastornos con repercusión estética

Cutaneous changes during pregnancy are exceedingly common. For instance, there are hyperpigmentation in the nipples, areolae, external genitalia, axillae and linea alba. Furthermore, 50% of women develope melasma. The most common change in connective tissue is the appearance of striae distensae on the abdomen, hips, buttocks and sometime the breasts, in 90% of women. Hyperemia is physiologic during pregnancy, and up to two thirds of women develop palmar erythema and/or spider angiomas.Although the influences that the individual hormones have on the skin are incompletely understood, it is thought that they are responsible, either primarily or secondarily, for many of the cutaneous changes that normally occur during pregnancy.     

Laser therapy of stretch marks

Striae distensae, better known as stretch marks, are a common disfiguring skin disorder of significant cosmetic concern. Many sources have reported the use of lasers to diminish the appearance of striae. Controlled clinical studies of the various treatment modalities available for striae are relatively uncommon, and much of the clinical data are anecdotal. The use of lasers alone or in combination with other therapeutic modalities can provide a safe and effective reduction in the appearance of both red and white striae distensae. Many of these therapies require special measures for darker skin phototypes. This article reviews the historical use of laser therapy for this disorder and discusses current therapeutic options.     

Efficacy of intradermal radiofrequency combined with autologous platelet‐rich plasma in striae distensae: a pilot study

Background Different types of laser have recently been reported as effective tools of treatment in striae distensae. Although fractional photothermolysis is effective for striae distensae, post‐inflammatory hyperpigmentation is a major concern and common complication. There are no reports of the effects of using an intradermal radiofrequency (RF) device in striae distensae. Autologous platelet‐rich plasma (PRP) is an effective treatment known for its wound‐healing effects. Methods Nineteen Asian female patients with striae distensae were enrolled in this study. Three sessions of intradermal RF (1134‐kHz frequency, 12‐W power, 26‐G electrode size) combined with autologous PRP were performed in each patient at intervals of four weeks. Patients were evaluated subjectively by the investigators and by themselves. Results Evaluation of clinical results at four weeks after treatment showed that only one (5.3%) of the 19 patients achieved excellent improvement, whereas seven (36.8%) demonstrated marked improvement, six (31.6%) showed moderate improvement, and five (26.3%) showed mild improvement. None of the patients showed worsening of striae distensae. A total of 63.2% of patients reported they were “satisfied” or “very satisfied” with the degree of overall improvement. Conclusions Intradermal RF combined with autologous PRP appears to be an effective treatment for striae distensae.     

Dermatoses in overweight and obese children and their relationship with insulin and skin color

Background/Aim

The aim of the present study was to investigate the prevalence of obesity-related dermatoses in obese children, and the association between these dermatoses and insulin resistance as well as skin color.

Methods

Obese, overweight, and normal weight children according to body mass index who were followed up and treated in the outpatient clinics were included in the study. Dermatological examinations of the participants were performed, and fasting insulin and glucose levels were checked.

Results

The obese and overweight children were evaluated as the patient group (70 girls, 41 boys, mean age: 12.37 ± 3.14 years). One hundred one healthy children with normal weight were determined as the control group (59 girls, 42 boys, mean age: 12.15 ± 2.43). The first five common dermatoses in the patient group when compared with the control group were keratosis pilaris (KP), striae distensae, hyperhidrosis, acanthosis nigricans (AN), and plantar hyperkeratosis. The first five dermatoses which were positively correlated with formation and insulin resistance were KP, striae distensae, AN, hyperhidrosis, and plantar hyperkeratosis. According to the Fitzpatrick skin scale, we found that the darker the skin color, the higher the probability of AN and KP (OR, 0.298; 95% CI, 0.106–0.834, p = 0.021; OR, 0.306; 95% CI, 0.117–0.796, p = 0.015, respectively).

Conclusion

Some dermatoses associated with obesity and insulin resistance were not found in obese children, or there was no significant association. These results indicate that many skin morbidities may be prevented by preventing and treating obesity and insulin resistance in the early period.     

Anatomy of striae

The histopathology of striae distensae is disputed; different authorities give contradictory accounts of the microscopic changes, especially in elastic fibres. We re-evaluated the problem by taking eight elliptical biopsies across striae. Six were examined by light microscopy with appropriate stains for elastin and collagen. Two were prepared for scanning electronmicroscopy (s.e.m.), using a procedure which removes collagen, enabling the elastic network to be seen in its native form. By light microscopy, striae were sharply demarcated from normal skin, consisting mainly of fine, straight bundles of collagen arranged parallel to the surface. Fine elastic fibres were disposed similarly without fragmentation, fraying or curling. By s.e.m., the elastic network was found to be extraordinarily dense and well developed with many fine, curled fibres in random array. It was evident that the routine stains for elastin greatly underestimated the abundance of elastic fibres, probably because immature fibres contain insufficient protein matrix. The horizontal packing of collagen bundles was confirmed by s.e.m. These findings support the view that striae distensae are scars. There is no evidence that they form by stress-induced rupture of the connective tissue.