Delusional Parasitosis (DP) is a rare psycho-cutaneous disorder characterized by a fixed false belief of being infested by parasites, despite the absence of medical evidence. This disorder often presents significant diagnostic and therapeutic challenges, particularly due to its infrequent occurrence and the high likelihood of initial presentations to dermatologists rather than psychiatrists.

To present a case series of DP, illustrating the clinical features, diagnostic processes, and treatment outcomes, while emphasizing the importance of early psychiatric intervention and a multidisciplinary approach.

This case series includes four patients diagnosed with DP at a tertiary care center over the course of one year. All patients were evaluated through comprehensive clinical assessments, including mental status examination, relevant laboratory tests, and neuroimaging. Treatment primarily involved the use of the antipsychotic olanzapine, supplemented with supportive psychotherapy and cognitive-behavioral therapy (CBT).

The case series involved three female patients and one male, all presenting with a firm belief of parasitic infestation. Despite multiple negative medical evaluations, these patients continued to experience tactile hallucinations and engaged in behaviors aimed at eradicating the perceived parasites. Treatment with olanzapine (5-20 mg/day) resulted in significant symptom reduction in all cases, with two patients achieving full remission and the other two showing partial improvement with encapsulated delusions. Supportive psychotherapy and CBT were instrumental in addressing distress and challenging delusional beliefs.

DP is a challenging disorder that requires a timely and integrated treatment approach. Antipsychotics, particularly olanzapine, combined with psychotherapy, have proven effective in managing symptoms and reducing delusional intensity. Early referral to psychiatric services and a collaborative approach between dermatologists and psychiatrists are crucial for improving patient outcomes. This case series adds to the existing literature on the management of DP and highlights the need for further research to refine treatment strategies.

Mohit Agarwal, Department of Psychiatry, Armed Forces Medical College, Pune, Maharashtra, India.