Striae (striae distensae), or stretch marks, are common in all ages due to thinning or atrophic defects in the dermis, typically in areas of repeated or prolonged skin stretching. The etiology likely involves the interplay of mechanical stress, hormones, and genetics. Striae are commonly located on the abdomen, thighs, and buttocks, or in areas where the skin stretches excessively. Striae are slightly more common in light skin phototypes and are twice as common in females.

Periods of rapid growth, such as puberty, pregnancy (striae gravidarum), training with weight lifting, rapid weight gain, and adolescent growth spurts, are common triggers. Striae also commonly occur in the setting of obesity. As 60%-70% of the US population is labeled as overweight or obese, the prevalence of striae from obesity is estimated at 40%. The skin findings themselves are rarely symptomatic, but they may occasionally indicate an underlying disease state (such as Cushing syndrome). In Marfan syndrome, striae are seen in around two-thirds of patients. Striae tend to flatten and become less conspicuous over time.

Bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, has been reported to cause ulceration of striae that have been induced by concurrent systemic glucocorticoid therapy.

Related topic: drug-induced skin ulcers