What describes atrophie blanche?

Atrophie blanche is characterized by the presence of a star-shaped, white atrophic scar that typically occurs as a result of skin trauma, such as from venous insufficiency or ulceration. The white appearance is due to the loss of pigmentation and dermal atrophy, creating a distinct scar-like lesion. These atrophic scars can often be found in areas of chronic skin changes, particularly where there has been previous inflammation or scarring.

The other options describe different skin conditions that do not correspond with the features of atrophie blanche. Raised, red scar tissue signifies keloids or hypertrophic scars, while flat, brown birthmarks (like café-au-lait spots) and dark purple bruises refer to completely different dermatological features unrelated to atrophie blanche. Thus, the unique presentation of a star-shaped, white atrophic scar defines this condition accurately.