Beyond Dementia: A Case Series of Primary Delusional Parasitosis in Cognitively Intact Octogenarians From North India

Delusional parasitosis is an uncommon psychiatric condition in which a person strongly believes that insects or parasites are present on or inside the body, even when there is no medical evidence to support it. Because the sensations feel real, most patients first approach dermatologists and only later come to psychiatric services. In older patients, these symptoms are often taken as part of a medical or neurological illness, such as dementia, so the possibility of a primary psychiatric condition may be overlooked. In this case series, we describe three patients aged 80 years or older who presented with similar complaints of crawling sensations, continuous itching, and a fixed belief that something was present on their bodies. All of them had already consulted several doctors before reaching psychiatry. On examination, they were alert, oriented, and able to communicate well, with only mild age-related cognitive changes that were not sufficient to diagnose dementia. Routine investigations, including blood tests, brain imaging, and dermatological evaluation, were normal in all cases. Treatment with second-generation antipsychotics led to some improvement in symptoms such as itching, sleep, and distress, but the main belief persisted. These cases suggest that, even in very old age, such symptoms are not always due to an underlying medical or brain disorder and may represent a primary psychiatric illness.