Antipsychotics are the mainstream treatment of delusional disorder. However, limited therapeutic effect was recognized due to side effect and lack of insight.

This article presents a case with Ekbom’s syndrome, also known as delusional parasitosis, who has significant response with Brexpiprazole.

A 58-year-old female developed her very first episode of psychosis 3 weeks before she visited our emergency department. Delusion of spiders laying eggs and bitsy spiders crawling over her body was claimed, followed by depressed mood and insomnia. The patient denied any substance use in recent months. Examination including biochemical studies, complete blood count, vitamin, and endocrine during admission were all normal. Brain image revealed senile cortical atrophy without apparent acute infarction. Cognitive abilities screening instrument (CASI) revealed total score 75, indicating borderline cognitive function. Ophthalmologist and dermatologist were consulted, and no specific abnormality was found.

Brexpiprazole 2mg was prescribed. After 3 weeks of treatment, the delusion improved with less parasitosis content. We discharged the patient, and kept following her at outpatient department with Brexpiprazole 2mg for 2 months. We tried to taper Brexpiprazole to 1mg at clinic, but her delusional parasitosis relapsed within 1 month. Therefore, we titrated the medication back to 2mg, and kept some dosage for 4 months. No more relapse of psychosis or significant movement dysfunction was observed. The total treatment course was 7 months.

Brexpiprazole, with its D2 partial agonism, shows impressive antipsychotic effect to Ekbom’s syndrome. Little side effect was observed in clinical practice, making Brexpiprazole a worth-trying psychopharmacological management of delusional parasitosis.

No significant relationships.

Delirium of parasitosis was first described by Karl Ekbom in Sweden in 1938. It is a hallucinatory monothematic delirium characterized by the unwavering conviction of having the skin infested with insects or parasites. Multiple etiologist has been described such as psychiatric and neurological disorders, substance intoxication or other medical conditions. We present a case of debut of Ekbom’s syndrome in an individual recently diagnosed with acute urethritis on antibiotic treatment.

To report a case of a patient with a debut of Ekbom’s syndrome and acute urethritis.

A 40-year-old man with no previous psychiatric history is admitted psychiatric emergency room accompanied by his wife for intense anxiety and isolation at home. During the examination, the patient explains a lot of fear of a series of bugs such as bees and small parasites that invade him. The onset of symptomatology coincides with a diagnosis of chlamydia urethritis and the initiation of treatment with ceftriaxone 500mg IM + Azithromycin 1g VO. Complete physical examination is performed without alterations. Toxicological, biochemistry, hormonal and vitamin study did not show any alterations.

Antipsychotic treatment was started with Olanzapine up to 10mg/day and supportive treatment with benzodiazepines. The patient showed rapid improvement. At discharge, he is asymptomatic from the urological and psychopathological point of view.

Ekbom’s syndrome is a multifactorial disorder. The patient was diagnosed of an acute psychotic disorder due to another medical condition and/or treatment with antibiotics.

No significant relationships.