Delusional parasitosis: a rare cause of pruritus in hemodialysis patients.

Uremic pruritus is a common symptom in patients undergoing hemodialysis (HD) or peritoneal dialysis, but its exact pathogenesis remains rather unclear. However, severe or "intractable" pruritus may be the manifestation of another underlying disease or disorder other than uremia. Delusional parasitosis, or Ekbom syndrome, is a rare psychiatric disorder characterized by the false conviction of being infested with parasites, and it can be primary, or secondary to several medical and psychiatric disorders. We report 2 elderly HD patients who presented one after another, with delusional parasitosis. At some point in time, the delusional beliefs of the first patient were adopted by the second patient who was waiting to start his HD session on the same bed and HD machine, on a subsequent shift. They were both diagnosed with Ekbom syndrome and described as having monosymptomatic hypochondriac delusion. They were both prescribed antipsychotic medications. During follow-up they admitted feeling better than before; however, they remained concerned about the "insects/parasites."