Delusional infestations: clinical presentation, diagnosis and treatment

Morgellons disease: a narrative review

Morgellons disease is characterized by the persistent delusion of skin infestation, ultimately inflicting wounds and impairing quality of life. There is insufficient and conflicting research pertaining to this condition, imposing challenges on clinicians in understanding, diagnosing, and treating it. In this review, we summarize the available literature on Morgellons disease including its historical evolution, epidemiology, proposed pathophysiology, underlying structural and functional brain pathologies, typical and atypical clinical presentations, diagnosis, and treatment. A comprehensive review of the literature was conducted on PubMed, Embase, and Scopus using specified keywords. Selected articles were screened by two independent reviewers based on set inclusion and exclusion criteria. Conflicts were resolved by a third reviewer as needed. No limit to the date of selected articles was set due to the scarce literature available on the subject. Morgellons disease is an underdiagnosed entity, owing mostly to the lack of an established pathophysiology and treatment guidelines. While many authors classify it as a type of delusional infestation (DI), others correlate MD with an underlying spirochetal infection, namely Lyme disease. Neuroimaging studies have revealed abnormalities in the "fronto-striato-thalamo-parietal network", a finding common to patients with DI, in addition to alterations in structures related to the "Itch Processing Pathway". Patients tend to extract fibers from their skin lesions and place them in a match box hence the term "match box sign". The diagnosis is that of exclusion, requiring extensive work up to rule out secondary causes and differential diagnoses. Treatment is largely based on the use of antipsychotics, with or without cognitive behavioral therapy. Despite being a diagnosis of exclusion, clinicians must be aware of this entity and have a profound understanding of the pathogenesis underlying it. Upon clinical suspicion, secondary Morgellons should always be ruled out through a thorough history taking, physical examination, and laboratory exams. Despite the challenges brought by the heterogeneous presentation of the condition and the paucity of research revolving around it, the great impact that Morgellons disease has on patients' quality of life forms a pressing need for its adequate detection, diagnosis, and treatment.

Delusional Infestation: A case of Ekbom syndrome in an elderly woman with a long history of HIV

A 70-year-old female presented with a long history of HIV and 5 years of disturbing delusions of infestation that impaired her daily functioning. The delusions resolved with haloperidol but were followed by depressive symptoms. The case presents the complexity of managing neuropsychiatric manifestations of HIV/AIDS with comorbidities in old age.

[From ocular itching to eye rubbing: a review of the literature]

Ocular itching and eye rubbing are frequent complaints in an ophthalmology practice. Numerous studies address the consequences of eye rubbing, such as keratoconus. However, there are few studies concerning the pathophysiology of itching, its transmission pathways, or its interactions with eye rubbing. Through this literature review, we will address the various clinical, physiological and therapeutic aspects of this pair of symptoms with a variety of ocular consequences. We will then describe the state of the art in itching and scratching in dermatology, in order to draw a parallel between these two vicious cycles. A better understanding of the pathophysiology of ocular itching and eye rubbing, as well as new studies based on dermatological data, might allow more appropriate clinical management of our patients and their symptoms.

Oral manifestations of delusional infestation: a case series

BACKGROUND

Delusional infestation (DI) is a rare psychotic disorder characterized by a patient's false belief that the body is infested with living or non-living organisms in the absence of clinical evidence of disease. Based on the underlying etiology, DI can be classified into primary and secondary forms based on the presence or absence of an underlying condition or previously diagnosed psychiatric disorder. This paper discusses a condition that is not commonly reported in the literature.

CASE PRESENTATION

Here, we describe four patients diagnosed with DI of the oral cavity. In each case, the patients' intraoral examinations revealed either traumatic lesions or no signs of mucosal disease. Management involved symptom management, medical therapy, and/or a referral to the primary care provider.

CONCLUSION

Because oral health care providers may encounter patients with DI, they should familiarize themselves with this unusual condition in order to recognize the condition and initiate prompt referral to a psychiatrist.

Delusional parasitosis: an entomological perspective after a 20-years-experience in two public medical and veterinary entomology laboratories

Delusional parasitosis (DP) is psychiatric disorder characterized by the unshakeable belief of being infested by endo- or ectoparasites, without any evidence of infestations. Hence, DP sufferers often consult medical entomologists or dermatologists, rather than seeking help from a mental health practitioner. Here we present 39 cases of suspected DP occurred in twenty years in two Italian public medical entomology laboratories, to highlight their common features and peculiarities, based on the interviews and material brought to our laboratories. Our results confirmed that DP affects both sexes, but is more frequent in females over the age of 50 years. Cases of psychological contagion, mostly affecting elderly people, were reported within seven family units. Some rare or unique features of DP sufferers involved: the fixed belief to be infested by endoparasites, olfactory hallucinations of unpleasant smell, self-harm to get rid of the imaginary parasite and suicidal thoughts. We suggest the term "Digital pics sign" to describe a modern derivative of the "Matchbox sign", where the DP sufferers showed pictures and videos, in person or sent by email, as proofs of being infested. Medical entomologists, being the most frequently contacted professionals by DP sufferers, may be crucial to raise awareness about this psychological disorder and to encourage a multidisciplinary approach amongst medical professionals and pest control operators.

“Doctor, You Must Examine My Creature Collection!”: A Case Report of Delusional Infestation

Delusional infestation--either secondary when attributed to a medical condition (including a bon-a-fide parasite infestation) or a pharmacologic agent (prescribed or illicit) or primary when secondary etiologies have been excluded--is a psychosis in which, for at least one month duration, the patient not only has a delusion that an animate organism or an inanimate pathogen has infested them, but also has abnormal tactile sensation (such as pruritus) of their skin caused by the etiology of their delusion. In patients over the age of 50 years, a delusional infestation is three times more common in women than men; however, delusional infestation in younger patients is often secondary, associated with illicit drug exposure, and equally common in women and men. Primary skin lesions are typically absent in delusional infestation patients; however, secondary skin lesions--resulting from the patient’s efforts to remove the parasite from their skin--can be observed, such as excoriations, prurigo nodules, scars, and ulcers. Delusional infestation patients typically strive to convince the person evaluating them that their infestation is valid and many of these individuals do this by collecting the parasites in a container. Presentation of the pathogen-filled containers is a pathognomonic feature of delusional infestation that has been referred to as either a positive creature collection sign, match box sign, parasite preservation sign, pillbox sign, or specimen sign. Morgellons disease--in which the pathogen being extruded from the skin is a fiber--has several features (including an excellent response to treatment with antipsychotic agents) in common with delusional infestation; therefore, most investigators consider Morgellons disease to be a variant of delusional infestation. Delusional infestation can be associated with numerous diseases, including comorbid psychiatric conditions. Indeed, up to 15 percent of delusional infestation patients have one (folie a deux) or more individuals with similar symptoms. A man with delusional infestation is described who had a positive creature collection sign, a fixed belief that his symptoms were caused by the infesting organism, and refusal to accept that he had a psychiatric disorder. He insisted that the evaluating dermatologist examine the pathogens in the clear plastic container he brought with him to his appointment. He was convinced that the pruritus of his scalp, eyebrows, and eyelashes was associated with a non-existent lice infestation. Secondary delusional infestation was excluded and his concurrent mild seborrheic dermatitis was treated topically; however, his itching did not resolve. He eventually agreed to seek treatment with a psychiatrist. The management of delusional infestation is based on its etiology; resolving the underlying medical condition or discontinuing the causative pharmacologic agent is the treatment approach for secondary delusional infestation, whereas low-dose antipsychotic agents are the intervention of choice for treating primary delusional infestation.

Stimulant use in patients presenting with psychocutaneous disorders

BACKGROUND

Psychocutaneous disorders are often attributed to stimulant medications, yet this relationship has never been fully elucidated. Literature on psychocutaneous disorders largely focuses on clinical presentation and treatment rather than disease etiology or exacerbation.

OBJECTIVE

To determine whether patients presenting with psychocutaneous disorders display high rates of stimulant use and psychiatric comorbidity.

METHODS

We undertook a retrospective cohort study of patients with psychocutaneous disorders presenting to a single center. It was hypothesized that these patients would have high rates of stimulant use and psychiatric comorbidity. Following analysis of baseline demographics, the patients were assigned to 1 of 2 groups: those with a psychotic disorder and those with a neurotic disorder.

RESULTS

Sixty percent of the patients (n = 317) with psychocutaneous disease had recently used a stimulant and more than 80% (270 of 317) carried an additional psychiatric diagnosis. The neurotic disorder group (n = 237) was younger and had higher rates of stimulant use. The psychotic disorder group (n = 80) had higher rates of psychosis, medical comorbidity, and illicit stimulant drug use.

LIMITATIONS

The predominantly Caucasian population may limit generalizability of findings as may the retrospective nature.

CONCLUSIONS

Patients with psychocutaneous disease have high rates of stimulant use and most have at least 1 psychiatric comorbidity.

Delusional infestation: Clinical presentations, diagnosis, and management

BACKGROUND

Delusional infestation is a primary psychiatric disorder characterized by a somatic-type delusional disorder (primary delusional infestation) that may lead to self-induced cutaneous lesions which are often difficult to recognize and treat properly. It may be also secondary to other psychiatric disorders, medical diseases, or substance abuse.

AIMS

This review will describe prevalence, common clinical features, different clinical presentations, differential diagnoses, and treatment recommendation. Special focus has been put on psychological aspects.

METHODS

We conducted a literature search on PubMed from January 2001 to June 2020 with the search terms of delusional parasitosis, delusional infestation, psychological, Reference lists of identified articles were examined for further relevant studies. The search was limited to English language articles. No specified quality criteria were used for study inclusion.

RESULTS

The clinical manifestations of delusional infestation are very important in the differential diagnosis and its psychological implications and management perspectives.

CONCLUSION

This article presents an update regarding the clinical aspects and treatment options of delusional infestation in order to provide an up-to-date review for dermatologists and general practitioners.

A systematic review of antipsychotic agents for primary delusional infestation

BACKGROUND

Delusional infestation (DI) is a rare delusional disorder in which individuals have a false belief that they are infested with bugs, parasites, or insects, despite the lack of medical evidence that such an infestation exists. Data on the effectiveness of antipsychotics for DI are limited.

METHODS

We conducted a systematic review using EMBASE, MEDLINE, PsycINFO, and Cochrane Central Register of Controlled Trials from inception of the databases up until July 20, 2018. Studies examining typical or atypical antipsychotics for primary DI were included.

RESULTS

A total of 51 relevant articles were identified, primarily case reports/series. Overall response was favorable for both typical and atypical antipsychotics, but there was no strong evidence to suggest that any one antipsychotic agent was preferable to other agents. Pimozide (1-16 mg/day) and risperidone (0.5-8 mg/day) were the most commonly studied typical and atypical antipsychotics, respectively. Inconsistent reporting of treatment outcomes and variability in study designs limited the overall evaluation of the data.

CONCLUSIONS

There remains a lack of sound data supporting the effectiveness of antipsychotic treatment for primary DI. Further research is required to establish more definitive conclusions about the relative clinical utility of antipsychotic agents for DI.

Current Understanding and Approach to Delusional Infestation

Delusional infestation is a psychiatric condition defined by a fixed belief of infestation despite contrary evidence. Diagnosis includes exclusion of organic etiologies. Treatment with antipsychotics is effective and safe in the majority of patients. Patients are characteristically reluctant to pursue psychiatric evaluation and may resist discussing their disease in psychiatric terms. Strategies to strengthen the provider-patient therapeutic alliance facilitate communication around appropriate treatment. Without antipsychotic medications, patients can become heavy utilizers of care and practice self-destructive behaviors in attempts to clear their perceived infestation.

Delusional infestation: a prototype of psychodermatological disease

Delusional infestation (DI) is a disorder in which patients express a firm, unwavering belief that they are infested with some type of organism but otherwise have a typical grasp on reality with relatively normal cognitive functioning. Although classified as a somatic delusional disorder, DI requires special consideration due to its complicated clinical presentation, requiring attention to several possible explanations for the symptoms the patients describe. The purpose of the current review is to first summarize the clinical background and features of the diagnosis then explore treatment options. DI is a rare disorder though has reported cases dating back to the 19th century and spanning across the globe. Patients often experience the disorder as secondary to a medical condition, including substance use/withdrawal. However, there have also been many reported cases of primary DI, occurring in the absence of any other psychiatric or medical disorder. Clinically, DI is a diagnosis of exclusion, where the physician must rule out other medical conditions, including genuine dermatological disorders or infestations, or contributions from medications or substances. Patients with the disorder more commonly present to nonpsychiatric healthcare providers, making it essential for all clinicians to be able to identify the disease. Treatment can include either first or second generation antipsychotics, but it is important to proceed tactfully in discourse with the patient, being careful to address patients in a straightforward manner without reinforcing or questioning the delusion and focusing conversation on what can be done for the symptoms. Future research can continue to evaluate pathophysiology underlying primary DI, which historically has been an under-studied topic.

Delusional parasitosis as presenting symptom of occipital lobe cerebrovascular accident

Delusional parasitosis manifests as a fixed, false belief that an individual is infested by living organisms. Primary delusional parasitosis is a psychiatric disorder with the delusion as an isolated manifestation, whereas secondary delusional parasitosis is a delusion occurring secondary to a psychiatric disorder, substance use, or medical illness. A 62-year-old woman with no psychiatric history presented to the Emergency Department with two to three months of "whole body itching" and seeing small insects crawling on her skin and in her hair. Exam of her skin and scalp was notable for no appreciable lesions, rashes, excoriations, or insects. Her neurologic exam was notable for full visual fields, and no localizing deficits. A non-contrast head CT demonstrated a nonspecific heterogeneous low-attenuation lesion within the medial right occipital lobe, and a follow up MRI confirmed a right posterior cerebral artery distribution subacute infarction. She was admitted for two days, and ultimately was discharged on aspirin and atorvastatin for secondary prevention. An emergency physician should remain vigilant in his/her assessment of patients with seemingly psychiatric symptoms, in particular elderly patients with no known psychiatric illnesses. Neuroimaging should be amongst studies considered in the evaluation of elderly patients presenting with new onset psychiatric complaints.

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.

Cortical features of distinct developmental trajectories in patients with delusional infestation

BACKGROUND

Although there is strong neuroimaging evidence that cortical alterations are a core feature of schizophrenia spectrum disorders, it still remains unclear to what extent such abnormalities occur in monothematic delusional disorders. In individuals with delusional infestation (DI), the delusional belief to be infested with pathogens, previous structural MRI studies have shown prefrontal, temporal, parietal, insular, thalamic and striatal gray matter volume changes. Differential contributions of cortical features of evolutionary and genetic origin (such as cortical thickness, area and folding) which may distinctly contribute to DI pathophysiology are unclear at present.

METHODS

In this study, 18 patients with DI and 20 healthy controls (HC) underwent MRI scanning at 1.0T. Using surface-based analyses we calculated cortical thickness, surface area and local gyrification index (LGI). Whole-brain differences between patients and controls were investigated.

RESULTS

Surface analyses revealed frontoparietal patterns exhibiting altered cortical thickness, surface area and LGI in DI patients compared to controls. Higher cortical thickness was found in the right medial orbitofrontal cortex (p<0.05, cluster-wise probability [CWP] corrected). Smaller surface area in patients was found in the left inferior temporal gyrus, the precuneus, the pars orbitalis of the right frontal gyrus, and the lingual gyrus (p<0.05, CWP corr.). Lower LGI was found in the left postcentral, bilateral precentral, right middle temporal, inferior parietal, and superior parietal gyri (p<0.01, CWP corr.).

CONCLUSION

This study lends further support to the hypothesis that cortical features of distinct evolutionary and genetic origin differently contribute to the pathogenesis of delusional disorders. Regions in which atrophy was observed are part of neural circuits associated with perception, visuospatial control and self-awareness. The data are in line with the notion of a content-specific neural signature of DI.

Psychocutaneous disease: Clinical perspectives

Psychocutaneous disease, defined in this review as primary psychiatric disease with skin manifestations, is commonly encountered in dermatology. Dermatologists can play an important role in the management of psychocutaneous disease because patients visit dermatology for treatment of their skin problems but often refuse psychiatric intervention. This review describes common psychocutaneous syndromes, including delusional, factitious, obsessive-compulsive and related, and eating disorders, as well as psychogenic pruritus, cutaneous sensory (pain) syndromes, posttraumatic stress disorder, and sleep-wake disorders. The updated classification of these disorders in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition is included. Strategies for management are reviewed.

Cimex lectularius ("Bed Bugs"): Recognition, Management, and Eradication

Reports of bed bug infestations in major cities in the United States and abroad have been in the public press. Physicians and other clinicians who care for children need to be able to recognize bed bug bites and understand the social, psychological, and medical implications that this diagnosis will have on patients and their families. In this article, a case presentation serves to guide discussion regarding establishing the diagnosis, differential diagnosis, and the management of bed bug bites and their complications. Integrated pest management programs involving housing managers, residents, and professional pest exterminators provide both chemical and nonchemical solutions for eradication of bed bug infestations.

Chronic Pruritus in the Absence of Skin Disease: Pathophysiology, Diagnosis and Treatment

Chronic pruritus arises not only from dermatoses, but also, in up to half of cases, from extracutaneous origins. A multitude of systemic, neurological, psychiatric, and somatoform conditions are associated with pruritus in the absence of skin disease. Moreover, pruritus is a frequently observed side effect of many drugs. It is therefore difficult for physicians to make a correct diagnosis. Chronic pruritus patients frequently present to the dermatologist with skin lesions secondary to a long-lasting scratching behavior, such as lichenification and prurigo nodularis. A structured clinical history and physical examination are essential in order to evaluate the pruritus, along with systematic, medical history-adapted laboratory and radiological tests carried out according to the differential diagnosis. For therapeutic reasons, a symptomatic therapy should be promptly initiated parallel to the diagnostic procedures. Once the underlying factor(s) leading to the pruritus are identified, a targeted therapy should be implemented. Importantly, the treatment of accompanying disorders such as sleep disturbances or mental symptoms should be taken into consideration. Even after successful treatment of the underlying cause, pruritus may persist, likely due to chronicity processes including peripheral and central sensitization or impaired inhibition at spinal level. A vast arsenal of topical and systemic agents targeting these pathophysiological mechanisms has been used to deter further chronicity. The therapeutic options currently available are, however, still insufficient for many patients. Thus, future studies aiming to unveil the complex mechanisms underlying chronic pruritus and develop new therapeutic agents are urgently needed.

Severe water intoxication and secondary depressive syndrome in relation to delusional infestation

This study presents a case of severe water intoxication in a female patient with delusional infestation. Self-induced excessive water ingestion is a rare medical condition, which has not been reported in patients with delusional infestation yet. The patient in this case study was a 60-year-old Chinese woman, who was admitted to our hospital because of a feeling of skin infestation. She suffered from loss of consciousness and generalized tonic-clonic seizure after drinking 12 L of water during bowel cleansing before colonoscopy. Sufficient laboratory and imaging examinations were performed to exclude other possible causes of severe hyponatremia, such as hypothyroidism, diabetes insipidus, and syndrome of inappropriate antidiuretic hormone. Besides, the cystic lesion in the posterior pituitary revealed by cranial magnetic resonance imaging was not accountable for her delusional symptoms as well as excessive drinking behavior. Her delusional symptoms were in complete remission with a combination of risperidone and aripiprazole. However, nearly 3 months after discharge, this patient suffered from depressed mood and was diagnosed with depressive syndrome, and even attempted suicide. This case highlights the possibility of self-induced water intoxication in patients with delusional infestation, inevitably adding to the complexity of the disease, and indicates the necessity of precautions for secondary psychotic or mood problems after symptomatological remission.

Delusional parasitosis with folie à deux: A case series

Delusional parasitosis (DP) is characterized by single hypochondriacal delusion in which patient feels he/she is infested with insects. The authors present a case series of three cases of DP with shared psychotic disorder (folie à deux) in which one individual developed a delusional belief in the context of a close relationship with another person or people who already had an established delusional idea. All patients of DP were assessed in the outpatient department of Psychiatry of a tertiary care hospital. Diagnosis of DP was made on detail clinical history and supporting clinical findings. All our primary cases had DP and the accompanying relatives of our patients had folie à deux as they shared the belief of parasite infestation which was firm and persisted despite evidence to the contrary. The primary cases of delusional parasitosis responded well to oral risperidone. The intensity of the belief in the secondary person also reduced with improvement in the symptoms of the patients.

Neural correlates of delusional infestation responding to aripiprazole monotherapy: a case report

BACKGROUND

The pathophysiology and appropriate pharmacological interventions for delusional infestation remain unknown.

CASE PRESENTATION

Here, we report a case of primary delusional infestation successfully treated with aripiprazole. We performed functional magnetic resonance imaging (fMRI) to investigate brain structures and functional modifications. Before antipsychotic treatment, pre- versus post-treatment fMRI images revealed a marked increase in brain activation in the supplementary motor area (SMA).

CONCLUSION

Our results highlight the efficacy and safety of aripiprazole in the treatment of delusional infestation and the possible role of SMA dysfunction in delusional infestation. Indeed, our results suggest that psychiatric improvement of delusional infestation is associated with normalization of brain activity, particularly in the SMA.