Delusional parasitosis and bipolar disorder: case report

Abstracts

O presente relato tem por objetivo descrever o caso de uma paciente portadora de delírio de infestação parasitária comórbido com transtorno bipolar. Trata-se de paciente portadora de transtorno bipolar há mais de 30 anos e que se encontrava com quadro psíquico estabilizado e sem alterações do humor durante as consultas psiquiátricas. Em uma das suas avaliações periódicas, começou a se queixar da presença de vermes que estavam infestando seu corpo, o que já vinha ocorrendo há 8 anos. Estava em uso de carbonato de lítio e não aceitou tomar o antipsicótico prescrito porque já experimentara efeito colateral com essa classe de medicamentos. A associação entre delírio de infestação parasitária e transtorno bipolar é rara, e os autores encontraram apenas um caso semelhante descrito na literatura médica internacional.

Transtorno delirante; síndrome de Ekbom; transtorno bipolar

CASE REPORT

Delusional parasitosis and bipolar disorder: case report

Carlos Eduardo Leal Vidal^I; Tábatha de Sousa Oliveira Barbosa^II; Ariadny Rodrigues Nunes^III; Clarisse Silva Freitas Souza^III

^IPsychiatrist, Faculdade de Medicina de Barbacena, Barbacena, MG, Brazil.

^IIResident physician in Psychiatry, Centro Hospitalar Psiquiátrico de Barbacena/Fundação Hospitalar do Estado de Minas Gerais, Barbacena, MG, Brazil.

^IIIMedical student, Faculdade de Medicina de Barbacena, Barbacena, MG, Brazil.

Correspondence

ABSTRACT

The objective of the present report is to describe the case of a patient with delusional parasitosis comorbid with bipolar disorder. The patient had been diagnosed with bipolar disorder over 30 years ago and her mental state was stable without any mood disturbances detected during psychiatric visits. During one of her periodic evaluations, the patient started to complain that worms were infesting her body, which had been occurring for the past 8 years. She was taking lithium carbonate and refused to use an antipsychotic because she had experienced side effects after using this class of drugs. The association between delusional parasitosis and bipolar disorder is rare, and we found only one similar case described in the literature.

Keywords: Delusional disorder, Ekbom's syndrome, bipolar disorder.

Introduction

Delusional parasitosis, also known as Ekbom's syndrome, is a psychiatric syndrome that causes the delusional belief that the patient's skin is being infested by insects, worms or other small animals.^1-3 There is an insidious onset of the disease and the delusion is typically preceded by primary tactile sensations, such as itching or paresthesia, or even hallucinations that trigger secondary delusional parasitosis.⁴

As an attempt to get rid of the animals using mechanical extraction or pesticides, the patient may cause a lesion or rash, which confirms the patient's belief that there is something wrong with his/her skin.³ Descriptions are often so detailed that suggest the occurrence of visual hallucinations. Skin lesions, which are present in most of the cases, typically occur in those parts of the body that are more easily reached by hands³ and are shown by the patients to prove the infestation. Patients frequently come to the doctor's office bringing desquamated skin, hair or even the "parasite" inside a recipient (box, glass or plastic bag). Such phenomenon, known as matchbox sign, is pathognomonic, but does not occur in all cases and affects approximately 30% of the patients.^2,3,5

The first case of this disease was described by Thibierge in 1884, who used the term acarophobia to name the syndrome. Other terms were dermatophobia, parasitophobia and entomophobia. In 1938, Ekbom described eight cases of delusional infestation using the term dermatozoenwhan to designate them.^3,6

Delusional infestation is more prevalent in individuals older than 50 years old, and women are more affected than men.³ In 15% of the cases, the delusional parasitosis is shared with more than one person (folie a deux or trois), usually people who live in the same house.^3,7

The diagnosis of delusional parasitosis is established based on the clinical history, but it is also important to take into consideration the presence of scabies, Grover's disease, chronic folliculitis and allergic reaction to insect bite in the differential diagnosis. Other psychiatric disorders, medical conditions such as alterations of sensitivity, use of substances or medications, or alcohol or cocaine abstinence, should also be considered.² Although delusional parasitosis is classified as a mental disorder, patients usually seek help from a dermatologist or general practitioner, and they almost always refuse psychiatric treatment.^3,4

In the present article, we present a clinical case of delusional parasitosis in a patient with affective bipolar disorder, which is the first case of this kind reported in the Brazilian literature.

Case description

The patient is a 66-year-old widow. She holds an undergraduate degree in the health field, is retired, Caucasian and catholic.

The patient sought medical care at the psychiatry outpatient clinic of Faculdade de Medicina de Barbacena in May 2006 to proceed with a treatment she had begun 30 years ago in Belo Horizonte, state of Minas Gerais, Brazil. She reported having bipolar disorder and using lithium carbonate (900 mg/day), clonazepam (2 mg/day) and chlorpromazine (100 mg/day). The use of these drugs was initiated after a psychiatric hospitalization in 1989. The patient reported she had used other medications before being hospitalized. During medical examination, her general appearance was good, her cognitive functions were unimpaired, and she presented with stable mood and no psychotic symptoms. She was able to speak fluently, was talkative and could provide information about her general state. She continued with the medication, and periodic medical visits were scheduled every 2 months. She did not have complaints or presented alterations in the following visits until March 2007, when she started to suspect of a neighbor and accused this person of having stolen her money. She was a little excited while she reported her complaints, but did not present other symptoms that suggested a manic state. The same medication was continued, and the manic state did not get worse. In November 2007, during her scheduled visit at the outpatient clinic, she seemed more talkative than usual, was in an irritable mood and had persecutory ideation. Trifluoperazine (5 mg) was prescribed. However, this drug was discontinued in the next month due to the occurrence of extrapyramidal symptoms and because there was improvement of the delusional symptoms. The patient returned to the outpatient clinic in April 2008, when she complained of worms in her anal area, and she informed that the parasites were not pinworms or ascarides. She was familiar with these terms. When she was asked about the supposed worms, the patient said that she had been infected 8 years earlier while cleaning a domestic sewage system using her hands, what caused a "wound on the back of her neck." The lesion had been diagnosed as an "infectious mollusk" by a dermatologist. She was treated with albendazol, betamethasone cream and loratadine, but there was no improvement of her condition. Some time later, after scratching the lesion, she realized that "the mollusks started to reproduce under her nails and they could metamorphose, being able to disguise as her skin or cuticle and bite her nails." She informed that the mollusks were lodged in her sacral region, but only bothered her when she was nervous, tired or upset. She showed her hands and pointed at small wounds that she claimed were caused by the worms. She reported that the mollusks did not enter her vagina, "possibly due to the acid pH."

Family History. Deceased parents and siblings. No family history of psychiatric disease. She had little contact with her parents during her childhood and lived in a day care center up to the age of 9. She did not inform the reasons of such situation.

Psychiatric History. The patient mentioned a psychiatric hospitalization. She said that during her crises, she used to become happy, talkative, willing to work a lot and did not feel like sleeping: "once a doctor discontinued my medication and prescribed maprotiline, then I had another agitation attack." She underwent three uterine curettages.

Physical examination. Presence of abrasions on both hands, mainly in her finger tips and under her nails. No evident lesions in the sacral region.

The treatment consisted of risperidone (1 mg), but the patient refused to use it, explaining that it had caused side effects when used concomitantly with another antipsychotic, and that her problem regarding the parasites was not related to a psychiatric disorder. Currently, the patient is still being treated at the outpatient clinic and keeps believing that her body is being infested by worms.

Discussion

According to Alonso-Fernandez,⁸ the delusional parasitosis is an unspecific state, lacking a psychopathological and nosological origin. This author states that the basic psychopathologic disorder, either a chronic tactile hallucinosis, a demential delusion or a primary or depressive delusion, corresponds to four nosological categories, respectively: symptomatic psychosis, organic psychosis, schizophrenia and vital depression.

Munro⁹ classified delusional parasitosis as a type of monosymptomatic hypochondriacal psychosis, characterizing a syndrome like "a single hypochondriacal, delusional system, distinct from the remainder of the personality." According to Munro, delusion can occur together with perception disorders such as illusions and hallucinations.

Other models have approached the delusional parasitosis as a possible manifestation of different patterns of psychiatric presentation, such as affective psychosis, organic psychosis and confusional and acute psychosis associated with alcohol abuse and chronic delusional disorders. From an etiological point of view, the disorder may arise from an unspecific symptom that must be approached according to an individual and multidimensional establishment of diagnosis. On the other hand, the symptom may be the manifestation of a primary psychiatric disorder or it can be secondary to a clinical problem.⁶

Therefore, delusional parasitosis can be primary or secondary. When it is primary, the delusion occurs spontaneously and meets the diagnostic criteria for persistent delusional disorder. In the case of secondary delusional parasitosis, there is an underlying clinical, neurological or psychiatric condition. The most common conditions are schizophrenia, dementia, depression, diabetes, neuropathies and strokes, but many other morbid conditions may be associated. Delusional parasitosis may also occur as a consequence of drug intoxication (amphetamines or cocaine) and also as a side effect of medications. A broad etiological classification can be found in Lepping & Freundenmann.¹⁰

In terms of psychopathological aspects, it is unclear if the primary disorder is a tactile hallucination or an illusion (or even a real sensation) like a subsequent delusional interpretation, or if this state is basically originated by a delusion.⁶ According to Berrios,¹¹ in clinical practice, tactile hallucinations are almost always associated with delusional interpretations.

In 1978, Skott¹² reported the findings of 57 patients, highlighting that delusional parasitosis affected older patients, whose mean age was 64 years; the disorder had a higher prevalence among females (42 women compared to 15 men); and the symptoms lasted for a mean period of 4 years before diagnosis was established. Among the patients studied, the following diagnoses were found: organic mental disorder such as dementia or diabetes (42%), paranoia (28%), folie a deux (25%), mental retardation (14%) and depression (12%).

Trabert¹³ conducted a thorough literature review including 1,223 cases of delusional parasitosis. Of all these cases, the author described the diagnostic categories of 449 cases, which were distributed as follows: "pure" delusional parasitosis, 40.3%; organic psychosis, 21.8%; induced psychosis, 14.4%; schizophrenia, 10.6%; affective psychosis, 9.1%; and neurosis, 3.5%.

The present case report describes a patient with Ekbom's syndrome, whose profile is very similar to the pattern found in the literature: female, older than 50 years old, social isolation and widowhood. The only exception is related to the educational level, which is usually low in these patients. Another characteristic of this disorder, also shared by this patient, is the resistance to use antipsychotics, since they believe they have a dermatologic disease.

In this patient, the occurrence of delusion several years after the establishment of the diagnosis of affective disorder and the persistence of such delusion, even in the absence of mood disorder, suggest that this is a primary delusion comorbid with bipolar disorder. The term comorbidity is used here to refer to the occurrence of two disorders in the same patient, regardless of the fact that these disorders have the same etiology or share the same psychopathological mechanism.

The previous medical history associated with the current psychiatric evaluation suggests that the patient has persistent hypochondriacal delusional disorder and bipolar affective disorder. We found several references to delusional parasitosis related to depressive disorders in the literature^12,14,15 and only one case of delusional infestation associated with bipolar disorder.¹⁶

References

• 1. Lepping P, Russell I, Freudenmann RW. Antipsychotic treatment of primary delusional parasitosis: systematic review. Br J Psychiatry. 2007;191:198-205.
• 2. Lee CS. Delusions of parasitosis. Dermatol Ther. 2008;21(1):2-7.
• 3. Goi PD, Scharlau CT. Síndrome de Ekbom acompanhada de automutilação. Rev Psiquiatr RS. 2007;29(1):97-9.
• 4. Le L, Gonski PN. Delusional parasitosis mimicking cutaneous infestation in elderly patients. Med J Aust. 2003;179(4):209-10.
• 5. Amâncio EJ, Peluso CM, Santos ACG, Magalhäes, CCP, Pires MFC, Peña Dias AP, et al. Síndrome de Ekbom e torcicolo espasmódico: relato de caso. Arq Neuropsiquiatr. 2002;60(1):155-8.
• 6. Vidal Castro C, Rejón Altable C, Sierra Acin AC. Percepción y pensamiento en los delirios de infestación. Actas Esp Psiquiatr. 2006;34(2):140-3.
• 7. Cordeiro Jr. Q, Corbett CEP. Delírio de infestação parasitária e folie a deux: relato de caso. Arq Neuro-Psiquiatr. 2003; 61(3B):872-5.
• 8. Alonso-Fernandez F. Fundamentos de la Psiquiatria Actual. vol. II. 3a ed. Madri: Paz Montalvo; 1977.
• 9. Munro A. Monosymptomatic hypochondriacal psychosis. Br J Psychiatry Suppl. 1988;(2):37-40.
• 10. Lepping P, Freudenmann RW. Delusional parasitosis: a new pathway for diagnosis and treatment. Clin Experiment Dermatol. 2007;33(2):113-7.
• 11. Berrios GE. Tactile hallucinations: conceptual and historical aspects. J Neurol Neurosurg Psychiatry. 1982;45(4):285-93.
• 12. Skott A. Delusions of infestation. Reports From the Psychiatric Research Center, No. 13. Goteborg: St. Jorgen's Hospital; 1978.
• 13. Trabert W. 100 years of delusional parasitosis. Meta-analysis of 1,223 case reports. Psychopathology. 1995;28(5):238-46.
• 14. Nicolato R, Corrêa H, Romano-Silva MA, Teixeira AL Jr. Delusional parasitosis or Ekbom syndrome: a case series. Gen Hosp Psychiatry. 2006;28(1):85-7.
• 15. Slaughter JR, Zanol K, Rezvani H, Flax J. Psychogenic parasitosis A case series and literature review. Psychosomatics. 1998;39(6):491-500.
• 16. Even C, Goeb JL, Dardennes R. [Bipolar affective disorder and Ekbom syndrome: apropos of a case]. Encephale. 1997;23(5):397-9.

Publication Dates

• Publication in this collection
  24 Aug 2009
• Date of issue
  2009

History

• Accepted
  11 Dec 2008
• Received
  11 Oct 2008