Derm Dx: Asymptomatic eruption between the shoulders

A 16-year-old black female presents complaining of an eruption between her shoulder blades. She is not sure when the eruption first appeared, but her mother complains that it is unsightly.

The patient denies pain or itch in the affected area. She also denies any prior past medical history or medication use. She reports that her sister has psoriasis and ...