A 31-year-old man is brought to the emergency department by the police after he assaulted a stranger who he thought was following him. The police report indicates that when the patient was arrested, he was shouting, "You don't understand, I'm the one who needs protection-the Russians are after my secrets!" In the emergency department, the patient is diaphoretic and tremulous. He is very easily distracted and cannot give a clear history. Temperature is 37 C (98.6 F), blood pressure is 164/102 mm Hg, and pulse is 112/min with a normal rhythm. Extraocular movements are intact, and the pupils are dilated. His speech is loud, rapid, and difficult to interrupt. Which of the following is the most likely diagnosis?

Question

A 31-year-old man is brought to the emergency department by the police after he assaulted a stranger who he thought was following him.  The police report indicates that when the patient was arrested, he was shouting, "You don't understand, I'm the one who needs protection-the Russians are after my secrets!"  In the emergency department, the patient is diaphoretic and tremulous.  He is very easily distracted and cannot give a clear history.  Temperature is 37 C (98.6 F), blood pressure is 164/102 mm Hg, and pulse is 112/min with a normal rhythm.  Extraocular movements are intact, and the pupils are dilated.  His speech is loud, rapid, and difficult to interrupt.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's psychotic symptoms (eg, delusions, paranoia), pressured speech, and signs of sympathetic stimulation (eg, diaphoresis, tremulousness, tachycardia, hypertension, mydriasis) are most consistent with cocaine intoxication. In high doses, cocaine and other stimulants (eg, methamphetamine) may cause paranoid delusions that are often indistinguishable from those found in primary psychotic disorders (eg, schizophrenia). Auditory, visual, or tactile hallucinations (eg, insects crawling under the skin) may also occur. Patients under the influence of stimulants frequently exhibit euphoria, hyperactivity, agitation, and grandiosity that may resemble an acute manic episode. (Choice A) Anticholinergic toxicity may cause tachycardia, hypertension, mydriasis, and psychosis. However, anticholinergic toxicity is characterized by both dry skin and mucous membranes rather than diaphoresis and presents with other classic anticholinergic effects (eg, urinary retention, decreased bowel sounds, hyperthermia). (Choice B) Dilated pupils, diaphoresis, and tremors are not expected in a primary manic episode of bipolar disorder. A diagnosis of bipolar disorder cannot be made if there is evidence that symptoms can be attributed to the physiological effects of a substance (eg, cocaine). (Choices D and G) Delusional disorder is characterized by ≥1 delusions lasting for ≥1 month that are not accompanied by other psychotic symptoms. Schizophreniform disorder may be diagnosed in patients who meet symptomatic criteria for schizophrenia for >1 month and <6 months. Neither diagnosis explains this patient's physical findings. (Choice E) Opioid withdrawal presents with gastrointestinal distress (eg, nausea, diarrhea, abdominal cramping), myalgias, mydriasis, piloerection, and lacrimation. Psychotic features are not seen. (Choice F) Phencyclidine (ie, PCP) intoxication may cause psychotic symptoms and violent behavior. It typically presents with prominent nystagmus, a finding notably absent in this patient. Educational objective: Cocaine intoxication can produce psychotic symptoms (eg, paranoid delusions), euphoria, and agitation. Physical signs indicating sympathetic stimulation (eg, tachycardia, diaphoresis, mydriasis) can assist in differentiating cocaine intoxication from primary psychiatric disorders. __________ References: An international perspective and review of cocaine-induced psychosis: a call to action. (http://www.ncbi.nlm.nih.gov/pubmed/24927026) Cocaine-induced psychotic disorders: presentation, mechanism, and management. (http://www.ncbi.nlm.nih.gov/pubmed/25392252) Cocaine-induced psychotic symptoms in clinical setting. (http://www.ncbi.nlm.nih.gov/pubmed/24679995)

A 31-Year-Old Man Is Brought to the Emergency Department by the Police