We present a 58-year-old woman with bipolardisorder and with a longstanding history of yellowbrown,hyperkeratotic papules in a seborrheicdistribution and nail changes. Her father andpaternal grandmother had similar eruptions and alsohad psychiatric disease. Histopathologic examinationshowed acantholysis and dyskeratosis, which wasconsistent with Darier-White disease. Darier-Whitedisease is a rare, hereditary disorder that is inheritedin an autosomal dominant manner and that usuallypresents in adolescence or early adulthood dueto mutations in the SERCA2 calcium pump. Theresultant alterations in calcium homeostasis affectdesmosome assembly and lead to acantholysis andapoptosis, which creates the characteristic eruption.Genetic linkage analysis of affected families showsthat a susceptibility locus for bipolar disorder cosegregateswith genetic markers that are found inthe Darier-White disease region. Treatments, whichinclude topical emollients, mild keratolytics, andtopical or oral retinoids, are aimed at improvingthe appearance of skin, relieving symptoms, andpreventing or treating infectious complications.