A white line on the thigh is mostly seen in atrophy lines, also known as expansion lines, white lines, is due to the fragility of the skin due to the degeneration of elastic fibers, and then subjected to excessive stretching to make it break, which leads to a linear atrophic depression on the skin. In addition, it can also be seen in flat moss, pityriasis furfuracea, etc.: I. Atrophic lines: 1. Etiology: due to various causes of excessive weight gain, excessive stretching of the skin, resulting in skin elastic fiber damage or fracture, skin elasticity is reduced, which leads to the appearance of atrophic lines. In addition, long-term suffering from Cushing’s syndrome, or long-term use of glucocorticoid drugs, can lead to hormone level disorders in the body, easily lead to elastic fiber rupture, the formation of atrophy lines; 2, symptoms: lesions can be manifested as a clear boundary wavy stripes, initially slightly above the skin surface, light red or purple; gradually fade to white, at this time slightly downward depression, soft texture and glossy feeling, there are fine wrinkles over the The surface of the stripe, usually no conscious symptoms, can be self-receding over time. Second, flat moss: the cause is still unclear, most often on the inside of the limbs, the surface of the lesion has a waxy film, visible white glossy dots or fine shallow white mesh stripes, often accompanied by pruritus. Third, pityriasis furfur: skin stratum corneum infected with Malassezia caused by, preferably in young and strong, at first for point-like white rash, then can be fused into flakes or stripes, the surface exists chaff-like scales, usually no conscious symptoms. Fourth, white scar: If the thigh has been locally traumatized or has undergone surgery, a scar may appear after recovery, which can be seen as a white stripe due to its light color. It usually does not affect daily life and does not require special treatment. However, if you feel that it affects the beauty, you can get rid of it by means of medication and laser treatment.