Long-acting paliperidone in Ekbom's syndrome in Lewy body dementia: A case report.

Introduction: Ekbom Syndrome (ES) is characterised by fixed, delusional beliefs that one's body is infested by parasites or other vermin in absence of supporting clinical evidence. Antipsychotic (AP) treatment, including long-acting injectable (LAI) AP in subjects with poor compliance, is prescribed to manage behavioural and psychotic symptomatology.

Objectives: We describe a 70-year-old woman who was hospitalised after experiencing new-onset delusions of infestation with visual and tactile hallucinations that led to bizarre behaviours and progressive social withdrawal.

Methods: She was diagnosed with ES and was initially treated with risperidone 3 mg; however, due to poor compliance and a lack of insight, she was switched to LAI palmitate paliperidone (LAI-PP). She was followed up for 8 months, administering Positive and Negative Syndrome Scale, Montreal Cognitive Assessment, Global Assessment of Functioning, Brief Psychiatric Rating Scale, neurocognitive assessment, and neuroimaging.

Results: After a progressive cognitive deterioration, she was diagnosed with an ES secondary to Lewy body dementia (DLB).

Conclusion: The LAI-PP treatment determined a complete clinical remission of psychotic symptoms despite the emergence of an iatrogenic akinetic-rigid syndrome. The delay of confirmatory neurological diagnosis, the associated risky behaviours of the patient, and poor treatment adherence led clinicians to prescribe LAI-PP following a good clinical response to oral paliperidone. However, in the case of a suspected DLB diagnosis, the prescription of an LAI-PP as a first-line strategy should be carefully evaluated.