Objective:

This systematic review aims to summarize the current evidence from case reports on patients with delusional parasitosis.

Background:

Delusional parasitosis (DP), also known as Ekbom syndrome, is a rare psychiatric disorder characterized by a persistent false belief of being infested with parasites despite the absence of any medical evidence. Although its exact pathophysiology remains unclear, DP is frequently associated with underlying psychiatric, neurological, or even infectious conditions.

Design/Methods:

We searched four databases (PubMed, Embase, Scopus, Web of Science) from August 2015 to August 2025. We included 122 case reports and case series describing the clinical, diagnostic, and treatment characteristics of patients with DP. No meta-analysis was performed due to the heterogeneity of the data. The JBI critical appraisal tool was used to assess the risk of bias of case reports and cases series.

Results:

We included 122 case reports of patients with DP. The mean age of onset ranged from 56 to 67 years with a female-to-male ratio of 3:1. The primary clinical manifestations included a fixed false belief of infestation (100%), formication (100%), and pruritus (80%). Patients commonly presented with self-induced skin lesions due to scratching and picking, including excoriations, lichenification, and scarring. A majority of patients (80%) had a past or comorbid psychiatric condition, most commonly depression (74%), followed by substance abuse (25%), and anxiety (20%). Regarding treatment, most patients were managed with second-generation (atypical) antipsychotics. First-line recommendations included risperidone and aripiprazole, while olanzapine and first-generation antipsychotics were typically considered second-line options.

Conclusions: