Derm Dx: A factory worker with an itchy rash on the wrists and ankles

A 42-year-old man presents with an itchy rash affecting his wrists and ankles. The eruption began approximately 6 weeks previously. He works in a manufacturing plant and was diagnosed at their health clinic with contact dermatitis. Treatment with mometasone cream has proven ineffectual. He is otherwise in good health and takes no oral medications. Examination reveals scattered erythematous papules, many ...