Week 4 – Methamphetamine Case Study

The Story of Mr L

Methamphetamine (also known as “meth,” “speed,” “crank,” and “ice”) is a strong CNS stimulant that has become an increasingly popular illicit substance of abuse. It can be smoked, snorted, or injected. Use of the drug leads to experiences of prolonged euphoria, increased alertness and energy, and decreased food intake and sleep (Page 12).


“Mr. L” is a 55-year-old man with a past medical history of hypertension. He has a psychiatric history of posttraumatic stress disorder and an extensive substance use history, going back to his late 20s, of cocaine. He presented to the emergency department with the complaint of having worms under his skin. He was agitated, and his hands were covered in multiple excoriations. The patient’s vital signs were unremarkable except for his blood pressure, which was 182 mmHg/121 mmHg, and pulse, which was 110 beats per minute. He was breathing at a rate of 22 breaths per minute, with an oxygen saturation of 97% on room air. His urine drug screen was positive for cocaine and amphetamines.

The patient carried a plastic bag containing blood, which he claimed was full of worms he picked out with a scalpel. He also brought the scalpel, two knives, and a methamphetamine pipe in his personal bag. Medical staff was unable to visualize worms in the plastic bag or on the patient’s body. His physical examination was unremarkable except for excoriations on the dorsum of his hands. The patient was alert and oriented to person, place, and time, and he denied auditory, visual, and tactile hallucinations. Review of his medical record revealed that he had a presentation for a similar complaint three weeks prior and was prescribed pyrantel pamoate for a possible hookworm infestation. At that time, he related a history of having washed his dog in an inflatable pool, and the worms crawled from the dog and inside of him through his toenails, which were recently trimmed and bleeding.

A psychiatric consult was ordered due to the ongoing questionable complaint, not validated by others, as well as his history of mental illness, his high level of distress and agitation, and his drug screen results. The patient was ultimately admitted to an involuntary inpatient unit.

On initial encounter with the team, the patient attempted to point out worms under his skin. He picked off pieces of skin and scabs and screamed, “See these are the worms, this isn’t skin, I know skin!” He angrily denied all psychiatric review of system questions, was not prescribed any home medications, and remained focused on his dermatological complaint. On further interview, the patient revealed an extensive substance use history, particularly cocaine (smoked) and, most recently, methamphetamine (smoked). He reported that his first cocaine use was 26 years ago, with intermittent episodes of use, in much smaller amounts, throughout the years. A month prior to admission, he started smoking methamphetamine, an illicit substance he had not used in several years. He reported smoking, on average, 2 grams of methamphetamine every other day, with his most recent use on the day of his admission.

The patient was initially very distressed and would not cooperate with treatment until his dermatological condition was addressed. He was amenable to taking one dose of albendazole (400 mg) and initiating treatment with risperidone (2 mg twice daily). The following day, he was irritable and drowsy but maintained compliance with risperidone. The morning of the second day, he displayed complete resolution of his worm preoccupation. He was discharged on risperidone,

with a plan to taper off while being monitored for recurrence of symptoms. At discharge, the patient was calm, cooperative, and free of obsessional preoccupations. He was diagnosed with stimulant-induced perceptual disorder, with onset during intoxication.

Reference: Alec H. Fisher, B.A., Cornel N. Stanciu, M.D. Dartmouth. (2017). Amphetamine-Induced Delusional Infestation. American Journal of Psychiatry Residents Journal · December 2017. –Hitchcock Medical Center, USA. Page 12 – 13.