[A case of delusional parasitosis in severe heart failure. Olanzapine within the framework of a multimodal therapy]

Reframing delusional infestation: perspectives on unresolved puzzles

Delusional infestation (DI), a debilitating psychocutaneous condition, featured as a false fixed belief of being infested accompanied by somatosensory abnormality, behavior alteration, and cognitive impairment. Although management of primary causes and pharmacotherapy with antipsychotics and/or antidepressants can help to alleviate symptoms in most patients, the underlying etiology of DI still remains unclear. Morgellons disease (MD), characterized by the presence of cutaneous filaments projected from or embedded in skin, is also a polemic issue because of its relationship with spirochetal infection. This review aims to discuss the following topics that currently confuse our understandings of DI: 1) the relationship of real/sham “infestation” with DI/MD; 2) behavior alterations, such as self-inflicted trauma; 3) neuroimaging abnormality and disturbance in neurotransmitter systems; and 4) impaired insight in patients with this disease. In discussion, we try to propose a multifactorial approach to the final diagnosis of DI/MD. Future studies exploring the neurobiological etiology of DI/MD are warranted.

Delusional infestation. Ekbom´s syndrome in a 47-year-old woman. Case report

Introduction: Delusional infestation is a rare psychiatric disorder defined as a condition in which the patient has the unshakable belief and perception of being infested with parasites. Its treatment is difficult, and frequently includes antipsychotic medications (such as olanzapine or aripiprazole). Non-pharmacological treatment, particularly psychotherapy, can be used for less severe cases. Dermatologists and psychiatrists must take a multi-disciplinary approach (preferably in a psycodermatology dedicated clinic) since this type of patients sometimes refuse treatment.Case description: A 53-year-old female businesswoman describes a clinical history of five years of visual hallucinations, depressive symptoms, and generalized pruritus, along with the use of toxic substances to “clean” her skin and cloths. She reports similar symptoms in some relatives but they were not evaluated. Blood tests and analyses of the “specimen” brought by the patient were performed, yielding negative results. The patient had never been assessed by any specialist, and showed disoriented during the consultation. Follow-up was not possible due to the reluctance of the patient to follow the indications and seek psychiatric treatment. Moreover, the patient did not respond to further communication attempts.Discussion: Delusional infestation is an uncommon disease that endangers the patients and the people around them. Its treatment is difficult and long, and not conducting proper follow-up is a great risk. Its prevalence and incidence is variable and generally unknown. It can affect the patient, their next of kin, pets or the environment, and the “pathogen” can be a living organism or an inanimate object.  Conclusion: This case is important as it shows the hardships of treatment, adequate follow-up and care, as well as the need to improve how these patients are approached. Additionally, both classical and uncommon signs and symptoms could be observed as the patient stated that her relatives were affected (possible delusional infestation by proxy).

Delusional parasitosis on the psychiatric consultation service - a longitudinal perspective: case study

BACKGROUND

Delusional parasitosis is infrequently seen in hospital-based consultation-liaison psychiatry.

AIMS

Although there are many publications on delusional parasitosis, this report reviews a unique case that was diagnosed during a hospital admission and treated over the next 36 months.

METHOD

Case report and literature review.

RESULTS

This case report describes a 65-year-old man who was diagnosed with delusional parasitosis during a hospital admission for congestive heart failure and acute kidney injury. A longitudinal description of the patient's condition during the hospital stay and in the 36 months following discharge, during which time he was treated by a consultation psychiatrist, is provided.

CONCLUSIONS

In discussing the treatment of a challenging presentation, this case demonstrates the opportunity for consultation psychiatrists to initiate care in patients who might not otherwise seek psychiatric services. Patients with somatic delusions represent one group of patients who are unlikely to independently seek psychiatric treatment.

DECLARATION OF INTEREST

None.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Ziprasidone in the treatment of delusional parasitosis

Delusional parasitosis is characterized by a patient's fixed false belief of being infested with parasites or small creatures. The first-line treatment options are typical antipsychotics such as pimozide. However, the accompanying extrapyramidal side effects might limit their use. We report on a patient with a good response to pimozide combined with ziprasidone. Ziprasidone is an atypical antipsychotic drug with a lower risk of extrapyramidal symptoms; thus, it might be considered a good first or second treatment option for delusional parasitosis.

Delusional parasitosis in neurological patients

OBJECTIVE

Delusional parasitosis has been described in a wide range of patients with general medical conditions, but there are few reports about its frequency and possible pathogenic mechanisms in neurological patients. This paper describes this delusional syndrome in a sample of neurological patients.

METHODS

We reviewed all clinical charts of hospitalized patients at the neuropsychiatry ward of a neurological center, from January 2005 to June 2009. Cases with delusional parasitosis were described in terms of demographic, clinical and brain imaging features.

RESULTS

From a total sample of 1598 patients, we identified 636 patients with neurological disease (39.80%); of these, four patients showed delusional parasitosis (0.62% of the neurological sample). Their diagnoses were brain cysticercosis (n=1), cerebrovascular disease (n=2), and dementia due to vitamin B12 deficit (n=1). They were women in late life, with depressive features. Three of them had significant cognitive decline. Two of them had paraesthesia and pruritus related to peripheral neuropathy. One of them had pruritus of unknown origin (possibly hallucinatory).

CONCLUSIONS

Delusional parasitosis was infrequent in this sample of hospitalized neurological patients. Female sex, advanced age, depressive features, cognitive decline, pruritus and paraesthesia of peripheral or central origin may contribute to delusional parasitosis in this population.

Delusional infestation

This papers aims at familiarizing psychiatric and nonpsychiatric readers with delusional infestation (DI), also known as delusional parasitosis. It is characterized by the fixed belief of being infested with pathogens against all medical evidence. DI is no single disorder but can occur as a delusional disorder of the somatic type (primary DI) or secondary to numerous other conditions. A set of minimal diagnostic criteria and a classification are provided. Patients with DI pose a truly interdisciplinary problem to the medical system. They avoid psychiatrists and consult dermatologists, microbiologists, or general practitioners but often lose faith in professional medicine. Epidemiology and history suggest that the imaginary pathogens change constantly, while the delusional theme "infestation" is stable and ubiquitous. Patients with self-diagnosed "Morgellons disease" can be seen as a variation of this delusional theme. For clinicians, clinical pathways for efficient diagnostics and etiology-specific treatment are provided. Specialized outpatient clinics in dermatology with a liaison psychiatrist are theoretically best placed to provide care. The most intricate problem is to engage patients in psychiatric therapy. In primary DI, antipsychotics are the treatment of choice, according to limited but sufficient evidence. Pimozide is no longer the treatment of choice for reasons of drug safety. Future research should focus on pathophysiology and the neural basis of DI, as well as on conclusive clinical trials, which are widely lacking. Innovative approaches will be needed, since otherwise patients are unlikely to adhere to any study protocol.

Striatal lesions in delusional parasitosis revealed by magnetic resonance imaging

INTRODUCTION

Delusional parasitosis (DP) is a syndrome characterized by the firm conviction that small living beings infest the skin. The etiology can be primary and secondary. Structural brain abnormalities in DP have only been reported in case reports often subcortical vascular encephalopathy and right-hemisphere strokes in the temporo-parietal cortex. Systematic brain imaging studies are lacking. We aimed to identify a brain region with structural lesions in patients with DP in order to better understand the pathophysiology of DP.

METHODS

Nine consecutive patients with DP in a psychiatric outpatient department were assessed clinically and by means of cranial magnetic resonance imaging (MRI).

RESULTS

Five of the nine cases were diagnosed as having DP as psychotic disorders due to a general medical condition while three had DP arising from pre-existing psychiatric illness and one suffered from a delusional disorder, somatic type (primary form). Four of the five DP cases secondary to a general medical condition (one case could not be analyzed) had striatal lesions predominantly in the putamen. Thalamic or cortical lesions were found in one case, respectively. In the primary DP case and all cases secondary to another psychiatric disorder basal ganglia and subcortical gray matter lesions were absent. In all medical (secondary) DP cases subcortical white matter lesions were found mainly in the centrum semiovale. Three of the five medical DP cases showed severe generalized brain atrophy which was absent in the primary DP case and in the cases secondary to other psychiatric disorders.

DISCUSSION/CONCLUSION

We present the findings of the first structural MRI study in DP. Our results suggest a possible relevance of structural lesions in the striatum, predominantly the putamen, in the medical (secondary) DP-subgroup. Our findings are in line with other studies demonstrating that the putamen, in addition to its role in motor regulation, represents a brain area that mediates visuo-tactile perception. Disturbed functioning of the putamen and associated brain areas of the somatic/dorsal striato-thalamo-cortical loop might therefore play an important role in the pathophysiology of DP, which is characterized by somatic delusions, tactile misperceptions and sometimes also visual hallucinations. The involvement of the striatum and the efficacy of antidopaminergic antipsychotics indicate dopaminergic dysfunction in DP. Evidence from DP in intoxication with substances influencing the dopamine transporter (DAT) (e.g. cocaine, methylphenidate, bupropion) further supports this observation. Further neuroimaging studies in larger samples are needed to expand our preliminary knowledge obtained from this case-series study.

Second-generation antipsychotics in primary and secondary delusional parasitosis: outcome and efficacy

In the absence of controlled clinical trials, little is known about antipsychotic treatment in primary and secondary delusional parasitosis (DP). All available data on the efficacy of antipsychotics (APs) and the outcome in DP date back to the era of first-generation antipsychotics, whereas such data are lacking for second-generation antipsychotics (SGAs). To study outcome and efficacy of SGAs in all forms of DP by means of a case-based analysis, we extracted 63 cases from 434 available publications and assessed them by 2 independent raters using standardized criteria for efficacy and outcome. The time course of response and the SGA doses used in DP were also first studied. The sample was comparable to classic samples and comprised mainly secondary DP cases (56%). The median onset of effect occurred after 1.5 weeks, and the maximum effect occurred after 6 weeks (later in primary than secondary DP, 10 vs 3 weeks; P < 0.004). If a treatment of more than 8 weeks could be established, all cases responded at least partially. In the outcome analysis, partial or full remission was performed by 75% of cases (final outcome, therapy switches allowed). In the efficacy analysis, partial or full remission was reached in 69% of the situations when an SGA was introduced (without therapy switches). Secondary DP was more likely to respond to SGAs than primary DP (78% vs 59% trend). Risperidone and olanzapine were most widely used and resulted in full or partial remission in 69% and 72%, respectively. Doses were lower than those used in schizophrenia. This first retrospective case-based study provides low-level evidence that SGAs are effective in DP and that outcome is favorable, although a publication bias is likely. Our findings need to be confirmed by controlled trials.

Primary delusional parasitosis treated with olanzapine

Delusional parasitosis (DP) is a rare psychiatric disorder, predominantly observed in middle aged and elderly patients. It can manifest itself as an isolated delusional disorder (primary DP), as a symptom of another psychiatric disorder or as an organic or toxic psychosis. The typical antipsychotic pimozide was traditionally considered to be the gold standard for treating DP. Compared with pimozide, atypical antipsychotics have many advantages in terms of tolerability, but their effectiveness has only been shown in a few case reports, which do not differentiate between primary and other forms of DP. We present the case of a 77-year-old woman with primary DP who responded markedly to the atypical antipsychotic olanzapine (2.5 mg daily). She was treated in a psychiatric outpatient department with a follow-up period of 3.5 years. This is the first report of a successful olanzapine mono-therapy in primary DP in such a setting and the longest follow-up period ever reported. The need for maintenance treatment was demonstrated. Olanzapine in age-adapted doses should be considered as an alternative treatment. This paper also provides a review of all published cases in which primary DP was treated with atypical antipsychotics.

Antipsychotic treatment of primary delusional parasitosis: systematic review

BACKGROUND

Little is known about the treatment of delusional parasitosis with typical and atypical antipsychotics.

AIMS

To evaluate the effectiveness of typical and atypical antipsychotics in primary delusional parasitosis (delusional disorder, somatic type).

METHOD

A systematic review was conducted.

RESULTS

No randomised trials were found and hence we collected the best evidence from 16 other trials and case reports, separating primary from other forms of delusional parasitosis. Studies using typical antipsychotics showed partial or full remission in between 60 and 100% of patients. Analysis of selected patients with primary delusional parasitosis showed that typical and atypical antipsychotics were effective in the majority, but that remission rates did not differ significantly between typical and atypical antipsychotics.

CONCLUSIONS

In the absence of controlled trials there is limited evidence that antipsychotics are effective in primary delusional parasitosis. Rigorous studies are needed to evaluate their effectiveness and to compare typical and atypical antipsychotics directly.