Test your dermatology knowledge with this week's Derm Case Challenge.

Can you identify this skin ailment? Take this week's Derm Case Challenge to validate your diagnosis.

A healthy 25-year-old female presented for evaluation of an asymptomatic eruption on both lower legs of 1 to 2 months duration. There is no history of trauma. She has been on the same birth control pill for the last 5 years. She gives no history of cold intolerance or sensitivity. She works as a bank teller. See the full case...