A 20-year-old black man came into our medical center with a mildly pruritic scaly rash affecting his neck and upper body for 2 weeks. Physical exam revealed well-demarcated, hyperpigmented hyperkeratotic papules coalescing to form large plaques on his central chest, back, and shoulders. He had a reticulated pattern on his shoulders and arms (FIGURE 1). His face, intertriginous skin, genitals, mucous membranes, and lower extremities were spared. The remainder of the physical exam was unremarkable.
Woods lamp and potassium hydroxide (KOH) preparation were negative. Labs, including fasting blood glucose and thyroid function test, were normal. Our patient denied any recent travel, fever, night sweats, or weight loss. He noted only that he used the weight benches at the gym. His medical and family histories were unremarkable, and he was not taking any medications or supplements.
FIGURE 1
Plaques on chest, reticulated pattern on arms
What is your diagnosis?
How would you manage this condition?