Pink, scaly rash on the trunk and extremities

A 14-year-old male presents with an asymptomatic eruption on his trunk, arms, and legs that appeared 2 weeks ago. The rash began on his thigh and spread from there. On physical examination, scattered small, pink, scaly papules and patches with collarettes are noted on the trunk, proximal arms, and legs. The patient has a single larger pink patch with a ...