A comprehensive entomological survey on a suspected delusional parasitosis case in Shiraz

Background: Delusional parasitosis, also known as ‘Ekbom syndrome’ is a form of psychiatric disorder that patients believe there are some small parasites such as insects on their body and skin. Some patients experience crawling, itching, biting, and stinging on their skin but the main complaint of these patients is biting . These patients are usually resistant to psychiatric referral and psychotropic therapy. This study was done on a case of delusional parasitosis from Shiraz during 2018-19.Objectives: The purpose of this study was to confirm the absence or presence of any arthropod on the patient’s skin and house, and to investigate the effect of Crotamiton ointment on the reduction of the effects of the Delusional Parasitosis.Materials and Methods: A 40 years old man (almost blind) with biting and itching complaint especially on his face was referred to medical entomology department of Shiraz University of Medical Sciences. A team of entomologists have surveyed the patient skin and house and entomological sampling have been done to find any insects or mites into the patient’s home and on his skin. All sampled were transferred to the entomology laboratory of Shiraz health school and carefully were examined. The patient s skin has been checked for any symptoms of arthropod biting. Crotamiton was prescribed to reduce itching symptoms which were probably caused by Demodex spp.Results: All collected samples were analyzed in the laboratory and no arthropod infestation was found in the patient s home. Also no mite or any other arthropods were recorded from his skin. After one-month treatment period, his symptoms and itching had not changed and the case was referred to a psychiatrist for treating.Conclusion: Entomological survey showed that this case was a confirmed case of delusional parasitosis because all collected samples were free of arthropods and any sign of them. Crotamiton ointment has no effect on the reduction of psychiatric disorder caused by Ekbom syndrome and also has no psychological effects as placebo. Unfortunately, psychological consultation and routine treatment has no effects on this patient.