[Atypical presentation of delirium: risk of misdiagnosis and undertreatment].

An atypical presentation of delirium increases the risk of misdiagnosis and undertreatment. Three cases are presented in this article. A 65-year-old woman, admitted for malnutrition, has significant mood-related symptoms that resemble depression. A 50-year-old male, admitted with an abscess, necrotizing fasciitis and sepsis, appears to be suicidal. A 61-year-old male, admitted with pneumonia, has auditory hallucinations. All three patients turned out to have a delirium. The authors advise ruling out a delirium in all patients who have predisposing factors and who develop an acute psychiatric disorder while staying in the hospital, before considering other psychiatric diagnoses. Advice on how to improve the diagnostic process is given.