A patient presents with a pruritic, annular rash with fine scaling and central clearing, affecting the trunk and proximal extremities. The patient reports recent exposure to a new soap and laundry detergent. Which of the following conditions is most likely responsible for this presentation?
Correct Answer: B
Rationale: The presentation described is consistent with nummular eczema, also known as discoid eczema. Nummular eczema typically presents as circular or oval-shaped patches of eczematous rash with fine scaling and central clearing. It is often pruritic and can be triggered by exposure to irritants such as new soaps or laundry detergents. The distribution on the trunk and proximal extremities is also typical for nummular eczema. Tinea corporis (ringworm) would present with a more raised, scaly, and well-defined border with central clearing. Pityriasis rosea presents with a herald patch followed by smaller oval or round lesions in a "Christmas tree" distribution. Lichen planus would present with polygonal, purplish, flat-topped papules typically located on flexural surfaces and extremities.