Delusional parasitosis is characterized by the unshakeable belief of being infested with tiny (microscopic) insects. Patients spend much time trying to get rid of the bugs and suffer from these symptoms. Patients prefer to go to dermatologists because they have a strong conviction over the presence of a somatic disease and do not accept any psychiatric advice for their complaints. 'Folie a deux' or shared psychotic disorder (SPD) is a relatively rare syndrome, which has long attracted clinical attention. Delusional parasitosis is associated in 5-15% of SPD and can run within a family. We experienced delusional parasitosis as 'Folie a Deux' between a mother and her son and successfully treated them through early psychiatric intervention. We believe that attention should be drawn to DP with SPD.
Adult ; Delusions/*diagnosis/*psychology ; Ectoparasitic Infestations/psychology ; Female ; Human ; Male ; Middle Aged ; Paranoid Disorders/diagnosis/psychology ; Shared Paranoid Disorder/*diagnosis/*psychology ; Social Isolation

INTRODUCTIONIn tandem with our ageing population, it is observed there is a growing trend of elderly patients presenting for the first time with psychotic symptoms. Clinical experience suggests differences in the phenomenology of late-onset psychosis in our Asian context compared to studies done in the West. This study aimed to analyse the characteristics and psychopathology of first presentation psychosis in our local elderly and to determine the treatment outcome over a 12-month period.

METHODSA total of 64 subjects with first presentation psychosis were consecutively recruited. Those with a non-affective, non-organic psychotic disorder were evaluated using the Positive and Negative Symptoms Scale, the Clinical Global Impression Scale, Mini-Mental State Examination and the Beck's Depression Inventory.

RESULTSOf the 64 subjects recruited, 55 were enrolled in the study. 59.3% (n = 32) of the subjects were diagnosed to be suffering from very-late-onset schizophrenia-like psychosis, followed by delusional disorder in 31.5% (n = 17). The remaining 11.1% (n = 6) were diagnosed to have late-onset schizophrenia. The sample showed a high preponderance of women, with 88.9% reporting persecutory-type delusions. The majority of them were married and 80% of the subjects were living with relatives. Treatment was effective in ameliorating symptoms, but there was a high loss to follow-up of male subjects (81.8%).

CONCLUSIONThis descriptive study found sociodemographic and phenomenological similarities to other studies of late-onset psychosis in the West, except that social isolation and partition delusions were not prominent.

Age of Onset ; Aged ; Aging ; Female ; Geriatrics ; methods ; Humans ; Male ; Mental Status Schedule ; Psychometrics ; methods ; Psychotic Disorders ; diagnosis ; epidemiology ; Schizophrenia, Paranoid ; diagnosis ; epidemiology ; Schizophrenic Psychology ; Sex Factors ; Singapore ; Social Class ; Time Factors ; Treatment Outcome