Derm Dx: Intensely itchy purple papules

A 32-year-old woman presents with a 3-week history of an itchy rash covering her whole body. Physical examination reveals papules that are distributed on the trunk and extremities, including on both wrists. The patient states that the rash is intensely itchy. On closer examination of the papules, a white scale with a reticulated pattern is noted over the purple papules.