|Year : 2017 | Volume
| Issue : 2 | Page : 82-84
Delusion of parasitosis with folie à deux
Mrinal Gupta MD, DNB
Treatwell Skin Centre, Jammu, India
|Date of Submission||18-Feb-2017|
|Date of Acceptance||11-May-2017|
|Date of Web Publication||4-Aug-2017|
Treatwell Skin Centre, Jammu. - 180 019, J&K
Source of Support: None, Conflict of Interest: None
Delusion of parasitosis (DOP) is a primary psychiatric disorder characterized by the patient’s firm belief that they have skin symptoms due to an infestation with insects. Patients prefer to consult a dermatologist because of the firm belief and refuse psychiatric advice. Folie à deux or shared psychotic disorder is a rare presentation with DOP. We present a case of DOP in a 63-year-old female patient who presented with complaints of insects crawling over her body and over her 1-year-old granddaughter, which was shared by her son also. The patient had brought a box full of the collected ‘insects’, the characteristic ‘matchbox sign’, and had also taken the photographs of the ‘insects’ on her cell phone, which we termed as the ‘snapshot sign’. The patient was treated with olanzapine, which led to partial resolution of her symptoms.
Keywords: antipsychotics, delusion of parasitosis, ekbom syndrome, folie à deux, hypochondriasis
|How to cite this article:|
Gupta M. Delusion of parasitosis with folie à deux. Egypt J Dermatol Venerol 2017;37:82-4
| Introduction|| |
Delusion of parasitosis (DOP), also known as Ekbom syndrome, is a primary psychiatric disorder and is one of the most common presentations of monosymptomatic hypochondriacal psychosis characterized by an unshaken belief of having been infested by a parasite . Patients prefer to consult a dermatologist because of the idea of insects on the skin and often visit numerous dermatologists to find the cure and often refuse psychiatric advice. Folie à deux or shared psychotic disorder is a rare presentation with DOP in which the patient’s belief is shared by other family members also .
We present a case of DOP in a 63-year-old female patient who presented with complaints of insects crawling over her body and over her 1-year-old granddaughter, which was shared by her son also.
| Case report|| |
A 63-year-old female patient presented to us with complaints of itching and insects crawling over her body for the last 1 year. The patient could not acquire any relief of her symptoms despite numerous sprays of pesticides in her house. The patient had consulted numerous physicians and was treated for body lice and scabies a number of times with no resolution of symptoms. The patient was living alone and there was no history of any psychiatric disorder or intake of any medication other than antihypertensives, which she had been taking for the last 10 years. For the last three months, the woman’s son and his family, including his 1-year-old daughter, were also living with the patient. The patient and his son gave a history of noticing similar insects over the body of her granddaughter a number of times for which the child was also treated for scabies by the attending pediatrician. The patient had brought a box full of the collected ‘insects’, which consisted of fibers, threads, and other inanimate objects, the characteristic ‘matchbox sign’, and had also taken the photographs of the ‘insects’ on her cell phone, which we termed as the ‘snapshot sign’ ([Figure 1]). On examination, there were a few excoriation marks over the arms and the lower abdomen, but there was no sign suggestive of any infestation in either the woman or her granddaughter.
|Figure 1 Container containing imaginary insects ‘matchbox sign’ and the photograph of the ‘insects’ in patient’s cell phone, ‘snapshot sign’|
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On the basis of history, differential diagnoses of DOP, scabies, and ectoparasitic infestation were made, but on clinical examination there was absence of any ectoparasites or any telltale signs of scabies in the patient or her grandchild; therefore, the patient was diagnosed as a case of DOP with folie à deux.
The patient was advised a psychiatric consultation, which was refused by her and then she was started on Tab Olanzapine 5 mg/day for 4 weeks, which led to some resolution of the symptoms after which the patient was lost to follow-up. The patient’s son was counseled as regards the nature of the condition and was advised to keep the child away from the patient.
| Discussion|| |
DOP has been variously referred to as dermatophobia, parasitophobic neurodermatitis, parasitophobia, acarophobia, or entomophobia. The characteristic presentation of the condition is a fixed, false belief of a parasitic infestation in the patient who is usually fully functional in all other areas . It is a rare disorder and the exact prevalence rate is not known. The female-to-male ratio is 2 : 1, showing a female predominance. Reports demonstrate that the average age of onset of DOP is 55.6–65 years .
DOP can be primary, secondary, or organic. Primary DOP consists primarily of a single delusional belief of having been infested by parasite and comes under monosymptomatic hypochondriacal psychosis. Secondary DOP can occur in the context of other mental disorders such as schizophrenia, depression, and dementia. Organic DOP occurs secondary to organic illness such as hypothyroidism, vitamin B12 deficiency, diabetes, cerebrovascular disease, cocaine intoxication, HIV, allergies, and menopausal state .
The patients usually complain of crawling, burrowing, biting, or stinging of insects or seeing the insects or their eggs or body parts or extrusion of insects from the skin. The patients may also provide descriptive, complex life cycles in detail of these insects ,. This parasitic agent may not be confined to the skin but also involve the genital, oral, or ocular areas ,. On clinical examination, no obvious skin disease is present but there may be presence of numerous excoriations, which underline the efforts done by the patient to remove the insect from the skin. Patients often present with specimens of ‘parasites’ they have collected in a container, the so-called ‘matchbox sign’ . On microscopy these offerings are usually found to be fragments of the skin and hair, samples of fabric, dust, and dirt. Our patient also brought a container full of such ‘insects’, characteristic of the matchbox sign. Apart from this, our patient had also clicked numerous photographs of the ‘insects’ on her cell phone, which on close inspection were fibers and inanimate objects, which we named as the ‘snapshot sign’.
In around 12% of cases delusions are shared with another individual so-called folie à deux. It is defined as a delusion developing in an individual in the context of a close relationship with another person, who has an established delusion. This phenomenon is also more common in women and is more often observed between sisters, wife and husband, and mother and child, but may rarely involve most or even whole families ,.
The management of DOP is difficult and the most important aspect of treatment is exclusion of any underlying infestation and other psychiatric disorder. The establishment of a strong physician–patient relationship is important to ensure the compliance of the patient. Several drugs have been reported in the management of DOP, with pimozide being the most extensively used. Atypical antipsychotic agents such as olanzapine, risperidone, sulpiride, and quetiapine have been suggested as potential alternatives owing to their more favorable benefit–risk ratio ,. In our patient we chose olanzapine owing to its safety profile. Olanzapine can be started at 2.5 mg daily, and slowly titrated to a therapeutic dose of 5–10 mg daily .
The first-line therapy for folie à deux is the separation of the secondary case from the dominant case. If the symptoms do not abate, antipsychotic drugs may be needed .
| Conclusion|| |
DOP patients are seen more commonly in dermatology practice than in psychiatry clinics. Therefore, dermatologists should be well equipped with a basic understanding of the condition, differential diagnosis, and treatment for these patients.
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Conflicts of interest
There are no conflicts of interest.
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