Hello and welcome to healthcaremagic. Stretch marks form due to rupture of collagen framework of the dermis. On running the fingers over them, they can be felt as a gap in the skin. Formation of stretch marks is a type of atrophic scaring because there is loss of tissue/dermal collegen due to rupture of collagen. They are an inevitable consequence of weight gain, pregnancy, for example. Sometimes, over use/abuse of potent steroids either topical or oral steroids can also lead to formation of stretch marks over the inner thighs, abdomen. The skin of the inner thighs is delicate and abuse of potent topical steroids in this area causes early development of stretch marks as compared to other sites. Abuse of topical potent steroids+antifungal combination creams, which are available OTC, is the most common for causing stretch marks in the groin area. OTC combinations like panderm, panderm +, quadriderm, betovate-GM, Lobate-GM etc all contain potent steroids. Since people easily get them OTC therefore they keep using them for symptomatic relief from groin itching and may consequently develop stretch marks. regards