Exacerbation of Darier's disease with oral lithium carbonate therapy

Darier's disease is a rare, autosomal dominant disorder with well-recognised cutaneous manifestations. A high incidence of psychiatric disturbance has become well-established in this disease although the reasons for this are still unclear. We report a case of a 46-year-old female patient with Darier's disease also suffering from manic depression, whose rash flared dramatically soon after starting lithium carbonate therapy, despite concurrent treatment with acitretin. We discuss other cutaneous disorders associated with lithium therapy and mechanisms for its effect in Darier's disease. It is possible that lithium inhibits epidermal adenylate cyclase, leading to a reduction in intracellular cyclic AMP and a proliferation of epidermal cells, an effect previously found in vitro. Finally, we discuss the association of Darier's disease with other psychiatric disorders, and emphasize the potentially serious complications of lithium administration in such patients.