Cases That Test Your Skills

Infested with worms, but are they really there?

Current Psychiatry. 2023 August;22(8):48-53 | doi: 10.12788/cp.0376

References

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3. Kohorst JJ, Bailey CH, Andersen LK, et al. Prevalence of delusional infestation-a population-based study. JAMA Dermatol. 2018;154(5):615-617. doi:10.1001/jamadermatol.2018.0004

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Patients may experience genuine symptoms despite the delusional nature of DP, and it is important for clinicians to recognize the potential burden and anxiety these individuals face. Patients may present with self-inflicted bruises, cuts, and erosions to gain access to infected areas, which may be confused with skin picking disorder. Excessive cleansing or use of irritant products can also cause skin damage, leading to other dermatological conditions that reinforce the patient’s belief that something is medically wrong. During treatment, consider medications for relief of pruritus or pain. Focus on offering patients the opportunity to express their concerns, treat them with empathy, avoid stigmatizing language such as “delusions” or “psychosis,” and refrain from contradicting them until a strong rapport has been established (Table 2¹⁷).

Symptoms of DP can persist for months to years. Patients who fully recovered experienced a median duration of 0.5 years until symptom resolution, compared to incompletely recovered patients, who took approximately 1 year.¹⁸ Primary DP has slower improvement rates compared to secondary DP, with the median onset of effects occurring at Week 1.5 and peak improvements occurring at Week 6.¹⁶

OUTCOME Continued ED visits

Unfortunately, Mr. H does not follow through with his outpatient psychiatry appointments. In the 7 months following discharge, he visits the ED 8 times for alcohol intoxication, alcohol withdrawal, and methamphetamine abuse, in addition to 2 admissions for inpatient detoxification, during which he was still receiving the same scheduled medications (haloperidol 15 mg/d and quetiapine 200 mg/d). At each of his ED visits, there was no documentation of DP symptoms, which suggests his symptoms may have resolved.

Bottom Line

Because delusional parasitosis symptoms feel real to patients, it is crucial to build rapport to recommend and successfully initiate treatment. After ruling out nonpsychiatric etiologies, consider traditional treatment with antipsychotics, and consider medications for relief of pruritus or pain.

Related Resources

Sellman D, Phan SV, Inyang M. Bugs on her skin—but nobody else sees them. Current Psychiatry. 2018;17(8):48,50-53.
Campbell EH, Elston DM, Hawthorne JD, et al. Diagnosis and management of delusional parasitosis. J Am Acad Dermatol. 2019;80(5):1428-1434. doi:10.1016/j.jaad.2018.12.012

Drug Brand Names

Buprenorphine/naloxone • Suboxone
Haloperidol • Haldol
Hydroxyzine • Vistaril
Lithium • Eskalith, Lithobid
Methylphenidate • Concerta
Olanzapine • Zyprexa
Permethrin • Elimite
Phenobarbital • Solfoton, Tedral, Luminal
Pimozide • Orap
Quetiapine • Seroquel
Risperidone • Risperdal
Sertraline • Zoloft
Valproic acid • Depakote