A comprehensive entomological survey and evaluation of the efficacy of different therapies on a suspected delusional parasitosis case

Objective: Delusional parasitosis (DP) is one type of psychotic disorders. It is a multifactorial disorder with different etiologies. Given that very little attention is paid to entomological survey in these cases, a comprehensive study was designed and performed for the first time in Iran on a suspected DP case and its home from Shiraz during 2018-2019.

Methods: In this study, entomological survey, dermatological studies, and psychological and psychiatric interventions were done respectively on a 40-year-old man who was referred to as a suspected case of DP.

Results: No medical importance arthropods were collected from the patient's home. He was not infected with lice and other ectoparasites. Skin samples were negative for scabies, but he was infected with Demodex folliculorum at low level. Psychiatric studies showed that he was a secondary DP case with depression. No effect and partial remission were reported after treatment with risperidone (2-6 mg/d) and olanzapine (5 mg/d), respectively. Therapeutic effects of hypnotism were also not satisfactory.

Conclusions: In Iran, the most important challenges these patients faced with are as follows: the absence of a specific referral center, patients resort to self-treatment or traditional methods, and lack of a certain duration and dosage of antipsychotic for these cases. Comprehensive clinical trials should be done on this rare syndrome at the national level for better understanding the epidemiological profile of DP and finding the best method of treatment for Persian community.