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 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.     

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.     

In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution

Please cite this paper as: In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution. Experimental Dermatology 2010; 19 : e228–e233. Abstract: Melasma is a frequent pigmentary disorder caused by abnormal melanin deposits in the skin. In vivo reflectance confocal microscopy (RCM) is a repetitive imaging tool that provides real‐time images of the skin at nearly histological resolution. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders are the most suitable candidates for RCM examination but RCM features of melasma have never been reported. This study investigates the pilot use of RCM in melasma to provide a set of well‐described morphological criteria with histological correlations. RCM images were acquired from melasma skin and compared to adjacent control skin in 26 patients. Skin biopsies were obtained from eight patients. In the epidermis, RCM showed in all patients a significant increase in hyperrefractile cobblestoning cells. These cells corresponded to hyperpigmented basal keratinocytes in histology. In six patients, dendritic cells corresponding to activated melanocytes were also found in the epidermis. In the dermis, RCM identified in nine patients plump bright cells corresponding to melanophages. Interestingly, for a given patient, the topographic distribution of melanophages in melasma lesions was very heterogeneous. RCM also showed a significant increase in solar elastosis and blood vessels in the dermis. RCM is a non‐invasive technique that detects pigmentary changes in melasma at a cellular level resolution. Therefore, RCM provides an innovative way to classify melasma by pigment changes.     

Elastic fibers in striae distensae

Eight cases with striae distensae associated with obesity or prolonged corticosteroid intake were examined by light and scanning electron microscopy. Fine elastic fibers predominated in early lesions, while thick elastic fibers predominated in older lesions. In early lesions the periphery showed thick and tortuous elastic fibers, but in older lesions it was of normal appearance. It is suggested the elastic fibers in striae were newly synthesized and gradually increased and thickened with age.     

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.     

In vivo reflectance confocal microscopy characterization of silver deposits in localized cutaneous argyria

Localized cutaneous argyria is a rare condition secondary to skin deposition of silver following exposure to substances containing this metal. The clinical appearance and dermoscopy findings require deep melanocytic lesions and particularly melanoma metastasis to be ruled out. Silver deposits are usually confirmed by scanning electron microscopy and/or energy‐dispersive X‐ray spectroscopy. Herein we describe the in vivo reflectance confocal microscopy (RCM) features observed in one case of localized cutaneous argyria. These features include the presence of a hyperrefractile network in the papillary dermis and a periadnexal dotted bright pattern. In vivo RCM might be a useful tool for an early diagnosis of this uncommon entity.     

Reflectance confocal microscopy: an effective tool for monitoring ultraviolet B phototherapy in psoriasis

Background In vivo reflectance confocal microscopy (RCM) is a novel, noninvasive imaging technique which enables imaging of skin at a cellular resolution comparable to conventional microscopy. Objectives We performed a pilot study to evaluate RCM as a noninvasive tool for monitoring ultraviolet (UV) B phototherapy in psoriasis. Methods In six patients with psoriasis, lesional and nonlesional skin was selected for RCM imaging using a standardized protocol. Well‐known histological features of psoriasis were visualized: parakeratosis, acanthosis, agranulosis, papillomatosis, presence of epidermal inflammatory cells, increased number of papillary capillaries and increased capillary blood flow. RCM imaging was performed before the first irradiation with UVB phototherapy, after nine irradiations, at clearance and 12 weeks after clearance. In four patients, 4‐mm punch biopsies were obtained and stained with haematoxylin‐eosin. Additionally, immunohistochemical staining was performed with monoclonal antibodies specific for CD31, CD3, filaggrin, K16, Ki67 and CD1a for correlation to RCM images. Results There was a high correlation between clinical, RCM and histological features. Normalization of RCM and histological features corresponded highly to clinical improvement of psoriasis. Conclusions This study is the first to establish the use of RCM as an effective tool for noninvasive monitoring of UVB phototherapy in patients with psoriasis. Potentially, RCM could be used in many other skin diseases for monitoring therapeutic response on a cellular level in a clinical or research setting.     

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.     

Striae distensae of pregnancy. An in vivo biomechanical evaluation

Background and objective Striae distensae of pregnancy is a common finding. There is currently a lack of information about the rheological characteristics of such lesions. The purpose of this study was to compare the mechanical properties of striae distensae before and after delivery. Patients and methods A total of 79 primigravid entered the study. Rheological properties of skin were evaluated in vivo using a Cutometer® equipped with a 2-mm probe. Results Mechanical properties of striae distensae developing during pregnancy resembled those of the surrounding skin. By contrast, significant differences were yielded during post-partum. Extensibility of striae distensae was increased although parameters of elasticity remained normal. Conclusions Rheological properties of striae distensae of pregnancy vary in time. This might reflect the changes in hormones and in the mechanical stresses normally setting the skin under tension.     

Reflectance confocal microscopy for pigmentary disorders

Please cite this paper as: Reflectance confocal microscopy for pigmentary disorders. Experimental Dermatology 2010; 19: 233–239. Abstract: In vivo reflectance confocal microscopy (RCM) is a non‐invasive, repetitive imaging tool that provides real‐time images at nearly cellular histological resolution. Application of this technology to skin imaging during the last decade has been a great advance in dermatology. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders caused by abnormal amounts of melanin in the skin could be the most suitable candidates for RCM examination. This article reviewed the RCM applications in the characterization and management of pigmentary disorders. The application of RCM in pigmentary disorders has been expanded to describe hyper‐ and hypopigmentary disorders as well as pigmented skin tumors. The great advantages of non‐invasive and repetitive examination of RCM may provide its usefulness not only in the diagnosis and management of pigmentary disorders, but also in researching pathogenesis of pigmentary disorders.     

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.     

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.     

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.     

Reflectance confocal microscopy criteria of lichen planus‐like keratosis

Background Lichen planus‐like keratosis (LPLK) may be difficult to differentiate from melanoma and other skin cancers on sun‐damaged skin based on clinical and dermoscopic examination. Reflectance confocal microscopy (RCM) allows evaluation of skin lesions at high resolution. Objectives The aim of this study was to identify criteria for specific diagnosis of LPLK using in vivo RCM. Methods Lesions included in the study were derived from patients presenting for skin examination at a private dermatology practice specializing in skin cancer. We retrospectively analysed RCM features of 28 biopsy‐proven LPLK and compared them to RCM findings in skin cancers on sun‐damaged skin, including five in situ squamous cell carcinomas, six actinic keratoses, seven superficial basal cell carcinomas and eight melanomas. Results The main RCM features of LPLK and their relative frequencies were: (i) typical honeycomb pattern of the spinous layer (78.6%); (ii) elongated cords and/or bulbous projections at the dermal‐epidermal junction (75%); and (iii) numerous plump‐bright cells and/or bright stellate spots in the superficial dermis (92.9%). These RCM features correlated with the following histopathological findings respectively: (i) spinous‐granular layers without significant atypia of keratinocytes; (ii) elongated, bulbous rete ridges; and (iii) dense infiltration of melanophages and lymphocytes in superficial dermis. We propose diagnostic criteria that classify correctly 71.4% of LPLK, while avoiding misclassification of any of the skin cancers in the present series as LPLK. Conclusions We identified RCM criteria for diagnosis of LPLK that correlate well with histopathological findings and that allow differentiation of LPLK from skin cancer.     

Brooke–Spiegler syndrome: focus on reflectance confocal microscopy findings of trichoepithelioma and flat cylindroma

Brooke–Spiegler syndrome (BSS) is a rare, autosomal dominant disorder characterized by multiple adnexal tumours, especially trichoepitheliomas, cylindromas and occasionally spiradenomas. These lesions usually begin to appear in the second or third decade of life. Malignant transformation of pre‐existing tumours may occur. In vivo reflectance‐mode confocal microscopy (RCM) is a noninvasive method that can be used to visualize the epidermis and the upper dermis at almost histological resolution. It has been used to evaluate several skin conditions, especially malignant lesions, and has been reported to be useful for differentiating between malignant and benign skin tumours. Only a few studies have reported on the use of confocal microscopy to characterize the features of benign adnexal neoplasms. We present a patient with BSS who presented to our clinic with multiple skin tumours. The possible utility of RCM for identifying adnexal neoplasms is emphasized in this report, which also describes the observed microscopic features.     

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.     

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.     

First experiences using reflectance confocal microscopy on equivocal skin lesions in Queensland

Background/Objectives: Reflectance confocal microscopy (RCM) is a non‐invasive method of imaging human skin in vivo. The purpose of this study was to observe the experience of using RCM on equivocal skin lesions in a tertiary clinical setting in Queensland. Methods: Fifty equivocal lesions on 42 patients were imaged using a reflectance confocal microscope immediately prior to being excised. The images were then analysed blind to the histopathological diagnosis. The experience and problems encountered when using RCM on skin lesions for the first time was also observed. Results: On RCM analysis 12/13 melanomas (92.3% sensitivity, 75% specificity), 19/22 benign naevi (86% sensitivity, 95% specificity), 6/9 basal cell carcinomas (66.7% sensitivity, 100% specificity)and 6/6 squamous cell carcinomas and its precursors (100% sensitivity, 75% specificity) were diagnosed correctly when using histology as the gold standard. We identified three common problems that affected image quality: object artefacts; positioning artefacts; and movement artefacts. Conclusions: Using simple techniques we found that common RCM features were readily identifiable and common artefacts could be minimized, making RCM a useful tool to aid the diagnosis of equivocal skin lesions in a clinical setting.     

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.