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A 42-year-old man presented with abnormally thick skin of the palms. During adolescence, he developed discrete yellowish papules on his palms (Figure 1) and crusted red-brown bumps on his central chest, along the posterior margin of his scalp, and behind his ears.

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Figure 1.

The lesions were occasionally itchy and had not responded to mild topical steroids or antifungal treatments. The patient’s nails, which he described as “brittle,” had alternating bands of red and white with distal V-shaped notches (Figure 2). No other family members were similarly affected.

Figure 2.

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