Stretchmark creams and lotions are a waste of money, says study

A new study published in the British Journal of Dermatology* concludes that stretchmark creams and lotions are a waste of money. 

"Most of the existing products aren't based on solid scientific research," said Frank Wang, M.D., assistant professor and dermatologist at the University of Michigan Health System, who led the study.

Wang and his colleagues found the elastic fiber network in the dermis gets disrupted in a stretch mark. After giving birth, this network remains disrupted. Elastic fibers give skin its elasticity, or the ability to "snap back," after stretching. The skin tries to repair the disrupted elastic network but it does not appear to be effective, which in turn promotes the lax, loose skin seen in more mature stretch marks. 

Abstract

Background

Striae gravidarum (SG), or ‘stretch marks’ of pregnancy, begin as erythematous streaks, and mature over months to years to become permanent scar-like bands that may be hypopigmented, atrophic and lax.

Objectives

To investigate early molecular alterations that may promote laxity of mature SG, we investigated the dermal elastic fibre network, which provides human skin with elastic properties.

Methods

We obtained skin samples of newly developed, erythematous abdominal SG in healthy pregnant women. The elastic fibre network was examined by Verhoeff elastic staining and immunofluorescence staining of skin sections. Gene expression was measured by real-time polymerase chain reaction.

Results

The normal elastic fibre network appeared markedly disrupted in SG, compared with perilesional abdominal skin or control (normal-appearing hip skin). This disruption was accompanied by the emergence of short, disorganized, thin, thread-like ‘fibrils’, which were observed prominently in the mid-to-deep dermis. These fibrils were rich in tropoelastin (the main component of normal elastic fibres), and persisted into the postpartum period without forming normal-appearing elastic fibres. The emergence of these fibrils was accompanied by increased gene expression of tropoelastin and fibrillin-1, but not other elastic fibre components, including fibrillin-2 and fibulin-1, -2 or -5.

Conclusions

In early SG, the elastic fibre network appears markedly disrupted, and newly synthesized tropoelastin-rich fibrils emerge, likely as a result of uncoordinated synthesis of elastic fibre components. Because they are thin and disorganized, tropoelastin-rich fibrils likely do not function as normal elastic fibres do. These observations provide the foundations for elucidating pathogenic mechanisms by which laxity may develop in SG.

*Marked disruption and aberrant regulation of elastic fibres in early striae gravidarum," British Journal of Dermatology, November 2015. DOI: 10.1111/bjd.14027

http://onlinelibrary.wiley.com/doi/10.1111/bjd.14027/abstract