Diagnostic Conundrum: A Rare Case of Psychosis in Leptospirosis among Siblings with Folie à Trois

Folie à Trois is a rare presentation of psychosis. It has been described in several case reports, but there is a lack of studies to understand the mechanism and management of this disease. We presented a case of three siblings who share the same delusional idea initially induced by one of the sisters who had neuropsychiatric manifestations of leptospirosis. The siblings exhibited a shared pattern of aggressive behaviors, auditory hallucinations, and persecutory delusions toward each other. Intriguingly, two of the sisters displayed improvement even without pharmacological intervention. The case highlights the complexity of differentiating shared psychotic disorder from organic etiologies, emphasizing the importance of multidisciplinary assessments in unraveling intricate clinical presentations. The distinctive temporal resolution of psychiatric symptoms among the siblings underscores the need for nuanced diagnostic considerations in shared psychotic disorders. This case report contributes to the understanding of the interplay between infectious diseases and psychiatric manifestations, urging clinicians to exercise meticulous scrutiny in cases of shared psychotic disorders masquerading as organic illnesses.