Striae Distensae (SD) are common conditions which occur in areas where the skin is mechanically stretched. Such changes commonly occur in pregnancy as well as in puberty when they is are rapid growth and weight changes.
Under the microscope, this can be explained by dermal atrophy: it is dur to inhibition of the mitotic activity of fibroblasts resulting in reduction of collagen and glycosaminoglycan synthesis but probably the earliest evidence of dermal atrophy is a reduction in the diameter of the fibrils and then the collagen bundles become atrophic and separated
Treatments never allow disappearance of the condition and include topical creams (tretinoin 0.1%) as well as fractional and CO2 lasers (to view management of striae distensae, click HERE)
Systemic steroids are known to induce purplish stretch marks as part of Cushing’s syndrome (more HERE)
Topical steroids have anti-inflammatory action and are used in the treatment of inflammatory skin diseases such as eczema (atopic dermatitis) and psoriasis.
They also affect the skin as a whole and as an unwanted side effect, high potency steroids cause thinning of the dermis which manifests clinically as atrophy.
This study from South Korea seeks to measure the effects of topical steroids on the appearance of stretch marks in patients with atopic dermatitis (AD) and psoriasis.
AD and psoriasis patients were enrolled: with similar age and treatment duration:
Histopathology sections of skin lesions (and non-lesional skin) were done to evaluate for fibrosis and eosinophils infiltration. Slides from allergic contact dermatitis (ACD) were also included
In the dermis, the number of Eosinophils was counted and the density of skin fibrosis was measured (it was increased).
There appears to be a reduced risk of developing SD in AD when compared to Psoriasis
This might be due to eosinophils (eosinophlia), which induce skin fibrosis (by fibroblasts)
Source of information: L-07 Sung JC. Striae distensae due to topical glucocorticoids is relatively rare in atopic dermatitis than psoriasis patients. JSID Annual Meeting (Japanese Society of Investigative Dermatology, 日本研究皮膚科学会) 2015 – Okayama, Japan