Fibrillin microfibrils are reduced in skin exhibiting striae distensae

Abstract

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 microns 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.

Fluid Within Striae – An Unusual Phenomenon

“…The horizontal stacking of collagen is identical histologically to that of scars [3]. On comparing striae with normal skin, a significant reduction in vertical fibrillin fibres subjacent to the dermo-epidermal junction as well as in elastin fibres in the papillary dermis has been demonstrated, along with increased glycosaminoglycan content [4].…”

Collagen and Elastic Content of Abdominal Skin After Surgical Weight Loss

“…Only fibrillin and elastin fibers were diminished [9]. Collagen fibers in current series were diminished, and arrangement in strict parallel fashion, at right angles to strectching forces, failed to materialize.…”

Erişkin Obez Hastalarda Dermatolojik Bulgular

“…However the occurrence of striae correlates closely with obesity in literature 7,8 . A correlation between obesity and prevalence of striae was not detected in our study.…”