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| SYNOPSES OF PAPERS PRESENTED AT AMPICON 2006 |
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| Year : 2019 | Volume
: 39
| Issue : 1 | Page : 5-13 |
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Ekbom’s Delusional Parasitosis: A Systematic Review
Ahmed Al-Imam1, Ali Al-Shalchi2
1 CERVO Brain Research Centre, Faculty of Medicine, University of Laval, Canada; Department of Anatomy and Cellular Biology, College of Medicine, University of Baghdad; The Canadian Association for Neuroscience; The Japanese Association of Anatomists, College of Medicine, University of Baghdad, Iraq
2 Department of Neurosurgery, College of Medicine, University of Baghdad; Department of Neurosurgery, Baghdad Medical City; The Royal College of Surgeons of England, United Kingdom; The Iraqi Board For Medical Specializations, Iraq
| Date of Submission | 09-Nov-2015 |
| Date of Acceptance | 21-Nov-2018 |
| Date of Web Publication | 28-Jan-2019 |
Correspondence Address:
Ahmed Al-Imam
CERVO Brain Research Centre, Faculty of Medicine, University of Laval, Canada; Department of Anatomy and Cellular Biology, College of Medicine, University of Baghdad
Iraq
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/ejdv.ejdv_53_15
Objective To collect evidence-based and detailed up-to-date knowledge, using a detailed systematic review of the literature, that is specific to the condition of Ekbom syndrome, also known as delusional parasitosis (DP). This article reviews historical facts, epidemiology, pathogenesis, clinical features, subtypes and related conditions, associated diseases, psychosocial impact, economic considerations and management.
Background DP is a psychiatric condition and can be the earliest sign of a major psychotic illness. The condition was first described in the late 17th century in France. The etiology is neurochemical. The classic ‘matchbox’ and ‘specimen’ signs are characteristic. Treatment is via a multidisciplinary approach.
Methods A detailed search strategy was utilized across six databases led by prespecified keywords (62 in total), followed by the application of database-specific filters to scrutinize the hierarchy of literature for guidelines, systematic reviews, and randomized controlled trials in addition to medical papers with weak evidence.
Results A total of 38 references were used to extract the most relevant data. This article is divided into sections of topics, starting from a methodology to a conclusion.
Conclusion This review article will enable the medical researcher to obtain a detailed perspective of the condition of DP. Thus, a researcher can seek the highest evidence to initiate his original research.
Keywords: delusional parasitosis, Ekbom, matchbox sign, Morgellons, specimen sign
How to cite this article:
Al-Imam A, Al-Shalchi A. Ekbom’s Delusional Parasitosis: A Systematic Review. Egypt J Dermatol Venerol 2019;39:5-13 |
| Evidence acquisition, materials, and methods | |  |
A detailed search strategy was used across five databases: PubMed, the Cochrane Library, Scopus, metaRegister of Controlled Trials, and Open Gray. The search was conducted from June 15 to August 1, 2015.
The search was led by an exhaustive list of prespecified keywords of free text, Medical Subject Headings, and their combination. The number of keywords was 62, and they were categorized into five main themes: delusional parasitosis (DP) disease nomenclature and related terminology, sex categorization, age groups, terminology of investigative modalities, and terminology of therapeutics. Boolean operators and truncation were used to narrow and expand the search.
This was followed by the application of database-specific filters [Table 1] and [Table 2]. However, some restrictions (filters) were not applicable owing to the nature of some databases. Additionally, inclusion and exclusion criteria ([Table 3]) were created to scrutinize the hierarchy of available medical literature for guidelines, systematic reviews, and randomized controlled trials as well as medical papers with weak evidence (including anecdotal reports). | Table 1 Total number of papers before and after the application of filters (limits)
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 | Table 2 The filters (limits) that were applied across the searched databases
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 | Table 3 Inclusion and exclusion criteria, used to filter the searched papers
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The critical appraisal skills program appraisal tool was used to evaluate the papers from the filtered search results. This tool was practical and convenient owing to a number of reasons. Many articles failed (scored low) during the analysis via the critical appraisal skills program tool owing to multiple factors ([Table 4]). Among the appraised papers that were used to create this review article, four papers scored the highest. These four papers were thoroughly used in the citation of this literature review paper. It is worthy to mention that Lepping et al. [1] was the only systematic review ever found in the literature search process across six different databases. No well-conducted randomized controlled trials or other systematic reviews were found, owing to the low incidence of the disease.
| Results and discussion | | |
An in-depth analysis of the papers extracted via database search engines [Tables 5] and [Table 6] revealed the following:- Of 223 papers (prior to the application of filters and limits), only 38 papers (filters applied) were used for citation and referencing of this literature review paper. Out of the 38 cited references, only four papers scored with the highest level of evidence. These were extensively used in the citation of this paper.
- In the references, there were seven types of papers: websites, textbooks, case reports, retrospective and cross-sectional studies, reviews and systematic reviews, and others (where categorization of type of study was not applicable).
- The four papers (of the highest evidence) were review articles (three) and systematic reviews (one). In their systematic review, Lepping et al. [1] studied the antipsychotic treatment of primary DP. It was the only systematic review found in the searched literature.
| Introduction | | |
Patients with DP, also known as Ekbom syndrome, have the false/unshakeable belief that organisms/bugs are living in the skin and sometimes in other parts of the body. In young patients, DP can be the earliest manifestation of a major psychotic illness. It was first described by Thiebierge and Perrin ([Table 7]). Alistair Munro considered it a type of monosymptomatic hypochondriacal psychosis. Karl Ekbom described its principal manifestations in 1937–1938. In 1978, a pivotal monograph (by Annika Skott) with the term Dermatozoenwahn (coined by Ekbom) was published. Regarding a similar nonsynonymous condition (but within the same delusional complex) called Morgellons disease, first described by Thomas Browne in 1690, Mary Leitao [9] named it ‘Morgellons disease,’ which refers to a local area in France. She considered it a re-emergence of this ancient malady, which affected children of the Languedoc region of France in the 17th century, in which delusional skin infestation was by inanimate materials rather than bugs. Somatic delusions are among the most difficult conditions to treat in dermatology, and dermatologists must be sufficiently prepared to treat them; classical treatment is with antipsychotics [3],[4],[5],[6],[7],[8]. | Table 7 Historical landmarks and scientific progression in delusional parasitosis
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| Epidemiology and demographics | | |
Psychocutaneous disorders are more common in females; however, DP affects both sexes equally below 50 years of age, and the male-to-female ratio of having the disease is 1:3. DP is considered rare ([Table 8]); however, Ekbom stated that it is common for mentally ill people to believe they have creatures in and/or on the body. DP affects 2.37–17/million/year. The age of onset ranges from 55 to 68 years; however, primary DP may occur in adolescents, and those in the age group of 20–40 years must be dealt with the utmost concern owing to recreational drugs that may trigger or cause DP. The average duration of the disease is 3 years, but it may last for decades. There are no socio-economic, racial, or peculiar predilections; however, social demographics can be a factor. Many individuals with Ekbom syndrome are intelligent, high-functioning, professionals, medical professionals, and even psychologists [3],[4],[5]. | Table 8 Szepietowski et al. [8] survey, dermatologists encountering cases of delusional parasitosis
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| Pathogenesis | | |
DP may evolve as sensory misinterpretation that transforms into a tactile hallucination and consolidates into delusions, or a hallucination that progresses to somatic delusion. To understand the pathogenesis, it is essential to know the DP subtypes ([Table 9]) [3],[12].
DP’s exact etiology is multifactorial. It is of a neurochemical base, and this is confirmed by DP triggering by psychoactive agents, such as cocaine and amphetamine, its association with neurohormonal disorders and the aging process ([Table 10]) [13]. | Table 10 Multifactorial contribution to the pathogenesis of delusional parasitosis in elderly people
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Huber et al. [14] proposed that decreased striatal dopamine transportation (DAT) leading to increased extracellular dopamine underlies DP pathogenesis, and this was confirmed by Millard and Millard [5]:- Primary DAT inhibitors (cocaine, pemoline, bupropion, amphetamines, and others).
- Secondary DAT dysfunction (Parkinson’s disease, brain injury, and others).
Huber et al. [14] made the first structural MRI study showing the relevance of structural lesions in the corpus striatum (mainly the putamen) in secondary organic DP. This caused disturbed functioning of the putamen (which mediates motor and visuo-tactile perception) and associated brain areas of the somatic dorsal striato-thalamo-cortical loop. Moreover, the involvement of the striatum and the efficacy of antidopaminergic-antipsychotics in treating DP indicate dopaminergic dysfunction in DP. Freudenmann et al. [15] suggested the role of postsynaptic-D2 receptors in mediating the effect of antipsychotics and gave the first evidence of fronto-striato-thalamo-parietal brain circuits in mediating delusional infestation (DI), which is in the same spectrum as DP [3],[9],[12],[13],[14],[15],[16],[17].
| Clinical features | | |
Presentation can be diverse, and patients are regular visitors to hospitals, persisting in their need for a cure. More advanced/established cases involve repeated consultations to specialist services (emergency physicians, family physicians, entomologists, veterinary services, and even esteemed scientists) to eradicate the imagined infestation. Patients may present with ill-defined, persistent itching without evident delusions [5]. This is sometimes accompanied by the cutaneous sensation of bugs (formication), or even visual confirmation of bugs, involvement of the genital, oral or ocular areas (orificial DP) [5],[12]. Pruritus is reported in more than 80% of sufferers, and others describe crawling, burrowing, and biting. Attempts to extract the bugs produce extensive skin excoriations, which can also present with bruising, traumatic-alopecia, contact dermatitis, and scarring [3],[4],[5].
To relieve symptoms, the patient uses scissors, files, needles, penknives, and tweezers, and the most disturbed patients use surgical instruments, chemicals, corrosives, and pesticides. Old self-mutilated lesions appear: lichenified, excoriated, ecthymatous, or crusted [3],[4],[5]. Patients usually provide a small container (matchbox, pill container, or a sealed plastic bag), classically known as a ‘matchbox sign,’ or better called a ‘specimen sign,’ enclosing the assumed/imagined organisms. On microscopy, samples appear to be hair, skin, fabric, dust, dirt, serum, ants, and fleas, but devoid of real pathogenic organisms [5],[15].
The patient may even provide detailed description(s) and/or drawing(s) of the organisms’ movement/life cycle [5]. A scientist claimed he had discovered a new insect that infested his skin, and he made detailed sketches of the insect and its copulation as seen by him under microscopy [3].
Shared delusion
Approximately 5–15% of patients have associated delusion with a close relative; these are mostly female family members or sympathetic/submissive/socially and culturally isolated individuals. Such delusions are called ‘folie à deux,’ ‘folie à trois,’ and ‘folie a famille’ (folie is the French word for ‘madness’). Recently, the role of the media and internet has been observed in shared delusions (referred to as ‘folie à Internet’ or ‘cyberchondria’). The quality of life of the patient and their family members is severely jeopardized [4],[5],[12],[18].
Variants, subtypes, and related conditions
Many variants, subtypes, and related conditions of DP exist ([Table 11]). Similarly, there are numerous conditions that may coexist with DP [3],[5],[6],[12],[19],[20],[21]. | Table 11 Variants, subtypes, and conditions related to delusional parasitosis
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| Associated diseases | | |
DP can occur in diseases affecting the non-dominant hemisphere, as in cerebro-vascular accidents. Structural brain abnormalities that have been reported include subcortical vascular encephalopathy and right hemisphere stroke in the temporo-parietal cortex. Similarly, DP can be a part of senile dementia. It has also been described in pellagra, B12 deficiency, after coronary bypass surgery, as an adverse effect of phenelzine, severe renal disease, and others ([Table 11],[Table 12],[Table 13]). In a young adult, recreational drug abuse must be considered [5],[14],[16],[22],[23],[24],[25]. | Table 12 Case reports of interest, association with secondary delusional parasitosis
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| Histopathology | | |
Skin histology is completely normal without specific findings; however, secondary lesions may be evident owing to rubbing, scratching, and picking. However, other patients may attempt to persecute the invisible organism or the inanimate subject, and it can lead to lichenification, excoriations, ecthymatous changes, bruising, traumatic-alopecia, contact dermatitis, and scarring [3],[4],[5].
| Psychological, social, and economic consequences | | |
As in any psychological or physical disfiguring skin disorder, there is a negative effect on body image and self-esteem. Depression, frustration, anxiety, and social phobia may develop. Even the management of DP is always challenging and frustrating. To quote a patient’s frustration: ‘My creepy crawlies definitely caused anxiety and agitation. I remember fantasizing about cutting my own skin open and ripping my leg muscles to shreds.’ Moreover, shared delusions ([Table 14]) will jeopardize the quality of life of both the patient and their family and make treatment more challenging [5],[26],[27].
Suicide is a risk in such patients, and they should be admitted to hospital and to be carefully monitored. In severe DP, the physician may persuade the patient that treatment is necessary because of the psychological effect, telling them that the organism can be virulent in psychologically and physically fragile individuals. DP can revolve on a bio-psycho-social management model in collaboration with psycho-dermatologists, where stress reduction is pivotal [5],[28],[29]. Chronic DP will eventually result in skin scarring. In all chronic scarring dermatoses, psychosocial, and economic effects are evident [Tables 15] and [Table 16] [5],[30],[31],[32],[33],[34]. | Table 15 Boggild et al. [30] study of social effect in delusional parasitosis
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| Treatment | | |
The Perplexity of Management
The dilemma in DP (especially the primary type) is convincing the patient that their condition is psychiatric. Therefore, solid doctor–patient trust is essential ([Table 17]). If left untreated, DP becomes fortified against further measures. Delusion almost never resolves itself naturally, but there is a 50% chance of remission if a psychotropic drug is administered early after the onset of symptoms. A multidisciplinary approach between physicians, laboratory workers, entomologists, and pest control organizations is essential. The physician must struggle until the patient is motivated to use a specific therapy, usually a combination of psychiatric and psychosomatic therapy. It is vital to watch for secondary and self-induced skin lesions, such as cellulites, bruising, traumatic-alopecia, contact dermatitis, and scarring. The underlying cause in secondary DP should never be forgotten [3],[4],[5],[6]. | Table 17 Step-by-step approach to gain solid rapport with patients of delusional parasitosis
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The current first-line treatment is risperidone and olanzapine (atypical or second-generation antipsychotics), and the classical treatment was pimozide (first-generation antipsychotics). Pimozide showed recovery in 90% of cases; however, owing to its risk profile (extrapyramidal and cardiac toxicity), pimozide is now the second-line treatment. However, safer first-generation treatment includes haloperidol, perphenazine, and sulpiride [4],[5],[13].
Atypical (second-generation) antipsychotics have a safer profile and are better tolerated (than pimozide); however, major risks include metabolic dysfunction. Risperidone (dopamine blocker and serotonin antagonist) treats DP effectively at 1–8 mg/day. Olanzapine (a higher affinity serotonin blocker than dopamine antagonist) is effective at 5–10 mg/day. Full remission with second-generation antipsychotics is accomplished in 75% of cases within 3 months of therapy. Safe first-generation treatment is used as a second-line treatment, with sulpiride (selective dopamine antagonists) at 200–400 mg/day. Hanihara et al. [22] reported an unusual association of thalamic pain syndrome with DP, which was efficiently treated within 3 months using sulpiride (100 mg/day) and amitriptyline [2],[4],[5],[12],[13],[15],[22].
Pimozide is used as a second-line option. The initial dose is 2 mg/day, increased by 2 mg/week, up to 12 mg/day; however, pimozide can be effective at 2–4 mg/day. If the patient’s improvement persists, pimozide is tapered gradually by 1 mg every 1–2 weeks to reach the maintenance dose or total weaning; however, if the patient deteriorates later, pimozide can be restarted in a time-limited fashion to control an episode rather than continuous treatment. Similar recurrence may occur with atypical antipsychotics in DP, DI, and Morgellons disease [3],[5],[6],[7].
New treatments
Freudenmann et al. [15] reported the first effective use of aripiprazole (atypical antipsychotic) in drug-induced DI and ziprasidone in organic DI. Contreras-ferrer et al. [36] reported a good response to pimozide combined with ziprasidone, an atypical antipsychotic (with a lower risk of extrapyramidal manifestation); thus, ziprasidone might be a good first treatment option.
Depot antipsychotics can be considered in the case of a patient’s poor compliance with oral medications. To convince the patient of such an approach (depots), the ‘hyposensitization’ motivational strategy is used by explaining to the patient that their condition is analogous to extreme hypersensitivity of the most peripheral skin nerves [2],[5],[15],[36],[37],[38].
| Conclusion | | |
DP is a unique psychosomatic disorder that is challenging to both the patient and physician, and first descriptions date back to the 17th century. DI and Morgellons disease are within the same delusional complex. DP is rare with a mean age of onset from the sixth to seventh decades; however, it may occur from the second to fourth decades, where recreational substance abuse should be considered. DP can be either primary or secondary. Pathogenesis points to central neurohormonal mechanisms. Shared delusion can be a dilemma. The psycho-socio-economic effect is a massive burden. Treatment is via the multisectorial approach with a prime target to build trust and rapport with the patient to avoid ‘physician odyssey’ and psychotherapy using second-generation anti-psychotics as the first line of treatment; however, disease recurrence is common.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Tables 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13], [Table 14], [Tables 15], [Table 16], [Table 17]
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