What characterizes lichen planus?

Lichen planus is characterized by flat-topped, shiny, polygonal papules that are often red to purple in color and may display white, lacy streaks known as Wickham's striae. These lesions typically develop on the flexor surfaces of the wrists, on the legs, and sometimes in the mouth as erosive lesions. The distinct appearance, particularly the combination of the purple color and the white scales, is a hallmark feature of this condition, helping to differentiate it from other skin disorders.

Other skin conditions listed do not exhibit the specific presentation associated with lichen planus, which emphasizes the importance of recognizing the unique characteristics that define this diagnosis.