A man in his 60s presented with a long-standing pruritic rash. His father and sons had a similar rash. Physical examination showed alternating white and red longitudinal streaks and distal V-shaped notching of several fingernails (Figure, A), yellow-brown greasy papules on the thighs and chest (Figure, B), and small white papules on the gingivae coalescing into cobblestoned plaques (Figure, C). Skin biopsy showed suprabasal acantholysis and dyskeratosis. The combination of nail, mucocutaneous, and histopathologic findings with family history was consistent with Darier disease. Treatment with acitretin improved the skin disease.