23rd Annual Pain Medicine Meeting 2024

Delusions, Dependence, and Pain:

Buprenorphine Induction in Patient with History of Delusional Parasitosis and Acute on Chronic Pain of Self-Inflicted Scalp Wound

Authors Kavan Maguire Mulloy MD, Cylena Stewart MD, David Martinez-Garza MD

INTRO

● Buprenorphine (BUP) is highly efficacious as a medication for opioid use disorder (mOUD).
● Partial receptor activation has led to theoretical concern for poor analgesic performance, however BUP’s high affinity for opiate receptors is favorable for analgesia.
● Clinical studies have demonstrated sublingual BUP’s analgesic potency, “with 85% of cancer patients reporting pain control as good-very good.”
● Delusional Parasitosis (DP) is a rare condition where patients firmly believe they are infested by parasites despite clear/convincing evidence of the contrary, and is considered a rule out diagnosis.
● Psychiatric differential for DP includes

substance-induced pruritus, psychotic disorders,

and “other psychiatric disorders (i.e. OCD).”

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A Predictive Validity Comparison Between Domestic and International Students

METHODS

● See QR Code for full case presentation that provided the basis for this discussion.

DISCUSSION

● Studies have demonstrated sublingual BUP as an effective analgesic, as replicated here in this case.
● Given the overlap between chronic pain and OUD,

BUP is an excellent option for co-occurring

patients.
● BUP does not bind persistently to the mu receptor,

allowing other opiates for breakthrough pain relief.
● A diagnosis of DP carries heavy stigma for

patients. Alternative psychiatric diagnoses should be considered, and treatment must be initiated promptly to reduce morbidity and mortality in this high-risk population.
● Second-generation antipsychotics are considered first-line treatment for DP and for the more common differential diagnoses of patients presenting with a history of DP.

CASE REPORT

● 59M with PPHx of delusional disorder, somatic type “DP,” with chronic self-inflicted scalp wound, unspecified mood disorder, and obsessive-compulsive personality disorder.
● Patient with chronic behaviors for 12 years reportedly was spending 8+ hours daily “doing surgery on himself” leading to a 70%-area anterior scalp wound with poor healing. Involuntary hold due to risk of self-harm initiated on medical floor while being treated for osteomyelitis of the skull—followed by psychiatry, infectious disease, and plastic surgery consult teams.
● Transferred to inpatient psychiatry unit once adequate antibiotic coverage was established.
● Patient reports extensive work-up at outside hospitals, leading to DP diagnosis.
● He did not demonstrate fixed-false belief or endorse “delusions of parasites” to our team.
● He did endorse somatic sensations on his scalp

that led to his compulsive behaviors of picking

and cutting his skin for immediate relief, followed

by efforts to relieve self-inflicted pain through

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opiates.

● The patient screened positive for past episodes of

mania and depression.
● He reports increasing amounts of oxycodone (30

mg daily) “off the street” due to worsening pain.
● The patient was offered BUP induction. Last

dose of oxycodone 5 mg Q6H at 5PM followed successfully by 2 mg buprenorphine trial the next morning, titrated to discharge dose of buprenorphine-naloxone 4mg-1mg films TID, with good pain relief and control of cravings.
● Psychotropic medications changes included Lexapro 30 mg and Abilify 10mg, which reportedly reduced his urges of scalp picking.
● The patient’s diagnoses were updated to OUD, obsessive compulsive disorder, and bipolar disorder with psychotic features.
● At 6 months follow up, patient remains stable with

adequate pain control, compliant with mOUD, no mood symptoms or delusional thought content, and follows-up with psychiatry and psychology monthly.

BUPRENORPHINE INDUCTION IN PATIENT WITH HISTORY OF DELUSIONAL PARASITOSIS AND ACUTE ON CHRONIC PAIN OF SELF-INFLICTED SCALP WOUND