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

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.

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.

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.

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

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.