Efficacy Of Combined Microneedling Plus Tretinoin 0.025% Or Timolol 0.5% In Treatment Of Stria Rubra

Striae distensae are most commonly found on the thighs, buttocks, and breasts in girls, and on the lumbosacral area or the outside surface of the thighs in boys. SG appears in the third trimester on the abdomen, breasts or thighs. They are more common in young primigravidae and are linked to higher pregnancy weight, large for gestational age new born, and a higher risk of traumatic vaginal birth .

The SD comes in two forms: striae rubrae (SR) and striae alba (SA). The initial erythematous, stretched flat lesions that are aligned perpendicular to the direction of skin tension represent the acute stage (SR) and they can cause mild itching. The chronic stage (SA) is described when SD have faded and appears atrophic, wrinkled and hypopigmented .

The most common causes of SD include a growth spurt during puberty, pregnancy, positive family history, obesity, and rapid weight gain or loss . Genetic causes including Marfan syndrome, Ehler-Danlos syndrome, and ectodermal dysplasia .

Other causes include cushing disease, anorexia nervosa, infections like T.B and typhoid, chronic liver disease and impaired elastic fibres of dermis. Iatrogenic causes include long term use of topical and systemic steroids and anti-retroviral drugs . Overstretching of the skin lead to dermal damage with inflammatory edema leading to rupture of collagen, elastin and fibronectin. Additionally, there is a defect in fibroblast function, with decrease in fibrillin and elastin production and lack of collagen organization . The treatment modalities for SD range from topical agents to more advanced laser and energy-based devices . Topical treatments such as tretinoin and glycolic acid are widely used for their ability to enhance collagen production and improve skin texture.

Lasers and light devices, particularly fractional CO2 lasers, efficiently promote dermal remodeling and improve the appearance of both SR and SA. No single therapy has emerged as the "gold standard," and combination therapies are recommended . Microneedling as a method of treating stretch marks, stimulates intradermal collagen production , also it can be used as a method of achieving trans-epidermal drug delivery.it also helps elimination of damaged old collagen . Microneedling leads to the release of several growth factors, including platelet-derived growth factors, fibroblast growth factors, and transforming growth factors alpha and beta, which stimulate the migration and proliferation of fibroblasts, producing new collagen and elastin in the papillary dermis. In addition, new capillaries are formed, this neovascularization and neocollagenesis following treatment lead to reduction of scars. The procedure is therefore called "percutaneous collagen induction therapy" .