Delusional parasitosis: lessons learnt

Abstract

Delusional parasitosis manifests in the patient's firm belief that they have skin symptoms due to an infestation with insects. Patients often refuse to seek psychiatric care. This study reassessed patients with delusional parasitosis in order to review and learn from them, which is important due to the significant morbidity of this condition and the therapeutic difficulties it presents to the dermatologist. Between 1995 and 2008, 13 patients with delusional parasitosis (6 men, 7 women; mean age 46 years) were included in this retrospective study. Mean duration of follow-up was 50.1 months. Nine patients were treated with pimozide, but only two had complete remission. Four were treated with sulpiride with two reported partial remissions. Risperidone was given to four patients, resulting in one partial remission. Eight patients were seen in the last 6 months and five were lost to follow-up. These findings highlight the difficulties encountered in diagnosing delusional parasitosis, the lack of response to neuroleptic medication, compliance problems and the dermatologist's dilemma of managing a psychiatric condition in a dermatological setting.