Folie à famille: A case report

Delusional parasitosis is a rare psychiatric disorder. Development of this condition as an induced delusional disorder among all family members (folie à famille) is even rarer. A family of three members developed folie à famille, and it was successfully treated with a second generation antipsychotic and geographical separation. Myths, stigma regarding Brief report


Introduction
Delusional disorder is characterised by the development of a single or a set of systematised persistent delusions (1). Clear and persistent auditory hallucinations, criteria to diagnose schizophrenia and evidence of organic brain disease are incompatible with the diagnosis (1). Delusional disorder constitutes 1% to 4% of all psychiatric admissions (2). Delusional disorder is predominantly an illness of middle to late adult life, more frequently occurring in lower socio-economic classes (3).
Shared delusional disorder (folie à deux), is characterized by the presence of similar delusions in two or more individuals. People who share the delusion usually have close emotional links (4). This is listed as a psychiatric disorder in DSM-IV (shared psychotic disorder, 297.3) and in the ICD-10 (induced delusional disorder, F24) (1). It is a relatively rare disorder (1). ICD-10 diagnostic criteria for induced delusional disorder requires that two people share the same delusion or delusional system and support one another in this belief, that these two people have an unusually close relationship, and there is temporal or contextual evidence to indicate that the delusion was induced in the passive member by contact with the active partner (1).
In shared delusional disorder, the individual who first develops delusions can usually be distinguished from secondary cases, in whom the symptoms are induced (5). The parent-child relationship is very common in folie à deux (5). Folie à famille is a form of folie à deux, where all the members of a family share the same delusion (6). The predisposing factors for folie à deux and folie à famille could be genetic or environmental (6). Shared past experience or expectations may also contribute towards the delusions.

Case Report
This case report highlights the diagnostic and management challenges of a rare induced delusional disorder in a family of three.
The family concerned consisted of parents (a 40-year old mother, and a 42-year old father) and their 19-year old daughter. The family was brought for treatment to the private sector, by their neighbour. All of them had been reluctant to seek psychiatric help until their neighbour, a school principle, compelled them to see a psychiatrist.
This was a close knit farming family of three members living in a rural village in the North Central province, 100 km away from Anuradhapura. None of the family members had a history suggestive of intellectual disability or an axis I psychiatric disorder, including substance or alcohol misuse.
The mother of the family had developed a soft lump over her shoulder 6 months previously. A general practitioner had diagnosed it to be a lipoma, and had referred her to a surgeon. She did not want surgical intervention, and had decided to leave it as it was. Thereafter she had started to scratch and damage the skin over the lump. She gradually developed the idea that this lump was infected with bugs. Over the passage of a few months, her feeling developed into a strong belief that her whole body was infected by bugs. Occasionally, she felt the bugs crawling underneath her skin and over her chest, limbs and neck. Once she tried to take the bugs out of Folie à famille her forearm using a kitchen knife. There were no other firm beliefs, delusions or perceptual distortions. The functions of her daily life had not been severely affected by this firm belief. She had sought local treatment, occult medical and religious practices but with no improvement. At the time she presented to us, the family had already lost a block of land and money worth around 200,000 rupees in search of alternative treatment.
From the beginning, the daughter of the family had believed her mother's story. She had accompanied her mother to local practitioners seeking a cure for the condition. She developed an itchy rash (a probable allergic reaction to tomato) 2 months after the onset of her mother's condition. Since then, she started to share her mother's belief of 'bugs crawling underneath her skin'. She believed that she had got infected by the bugs from her mother. She too had gone for different practices and medical quacks expecting a cure for her condition. A general practitioner of the village had once given her an ointment and a cream for local application, diagnosing the condition as a parasitic infection. Her symptoms continued to persist.
The father of the family was the next to develop the same belief. There was no precipitant in his case. Within a period of one month, he developed the firm unshakable belief that his skin was infected with 'bugs'. He started damaging the skin over his chest and upper arm using a pen-knife. On one occasion he had burnt his forearm with a mosquito coil to get rid of the 'bugs' (Figure 1). However, he had never seen a bug underneath his skin. He could perform his daily activities and had intact interpersonal relationships. reluctantly accepted the psychiatric diagnosis, and agreed to continue treatment at the private sector. Their neighbour was happy to help the family with drug adherence and financial support. Risperidone 2 mg nocte was prescribed for the mother who had the primary delusion. She agreed to stay with her sister in the neighbouring village until her condition improved. The father and his grown up daughter had no hesitation in staying separately in order to achieve a cure for their distressing condition. A plan was made to follow up the family monthly. The mother of the family adhered well to the prescribed treatment, and the family kept to the plan of management.
A significant improvement was seen in all three members of the family on their first follow up visit. They were no longer distressed, and the damaged skin was healed. The mother showed no side effects to the antipsychotic. The dose of risperidone was increased to 4 mg nocte, with as required benzhexol. The delusion had completely disappeared on the third month of follow up. None of the family members had the strong belief of 'bug infestation' anymore. They were happy to continue with the treatment as required.

Discussion
Though uncommon, cases of induced delusional disorders are being increasingly reported. Gralnick published the following classification of folie à deux subtypes in 1942 (7). This case report meets ICD and DSM criteria for shared delusional disorder. All three members of the family developed a delusional parasitosis, which is compatible with folie à famille or folie à trios. The 'primary' case was the mother, whilst the girl and her father are both 'secondary' cases. Antipsychotic treatment of the individual with primary delusion and separation from other family members was effective in the management. This case is compatible with folie imposee described by Gralnick. Mental status examination of the three members of this family revealed an encapsulated delusion of being infested with 'bugs'. Their mood was anxious with no incompatible perceptual disturbances. There were no cognitive deficits or significant deterioration of functional level. The mother of the family had occasional tactile hallucinations, in keeping with the delusion. Her diagnosis was compatible with a persistent delusional disorder, delusional parasitosis type.
The family refused treatment from the government hospital closest to their home due to stigma. They The patients in this case report had a delayed presentation to psychiatric services mainly due to stigma and their beliefs about the condition. The family had sought treatment from local healers for the mental health disorder, which was in keeping with their background. Unfortunately this had cost them a considerable amount of money, and had been to no avail. They had been very reluctant to seek psychiatric treatment for their condition due to the stigma associated with psychiatric disorders, myths surrounding such conditions, and lack of knowledge about the condition and available treatment. Awareness programmes at a national and local level is likely to be helpful in overcoming some of these obstacles.

Declaration of interest
None declared A Ellepola, Consultant Psychiatrist, Teaching Hospital, Anuradhapura