eISSN: 2299-0046
ISSN: 1642-395X
Advances in Dermatology and Allergology/Postępy Dermatologii i Alergologii
Current issue Archive Manuscripts accepted About the journal Editorial board Reviewers Abstracting and indexing Subscription Contact Instructions for authors Publication charge Ethical standards and procedures
Editorial System
Submit your Manuscript
SCImago Journal & Country Rank
1/2021
vol. 38
 
Share:
Share:
Original paper

Delusional infestation in clinical practice over a period of two decades

Radomir Reszke
1
,
Przemysław Pacan
2
,
Adam Reich
3
,
Jacek C. Szepietowski
1

  1. Department of Dermatology, Venereology and Allergology, Wroclaw Medical University, Wroclaw, Poland
  2. Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland
  3. Department of Dermatology, University of Rzeszow, Rzeszow, Poland
Adv Dermatol Allergol 2021; XXXVIII (1): 144-150
Online publish date: 2019/10/07
Article file
- Delusional.pdf  [0.20 MB]
Get citation
 
 

Introduction

Psychodermatology is a relatively new field of medicine created from merging dermatology and psychiatry which explores complex interactions between the mind and the skin [1]. Occasionally, patients presenting to dermatologists may complain of symptoms primarily of psychiatric origin. Such is the case with individuals suffering from delusional infestation (DI) who have a false belief that their skin and body are infested by small vivid pathogens or inanimate objects [2]. DI has many synonyms in the literature, firstly described as acarophobie by Thibierge (1894), and was subsequently termed präseniler dermatozonewahn, delusions of parasitosis or Ekbom’s syndrome [3]. The annual incidence rate of DI was estimated as 16.6 cases per million inhabitants, with a prevalence of 83.21 cases per million. Women are approximately 2.5 times more often affected than men, although this observation concerns women aged 45 years and older suffering from primary DI [2]. Primary DI cannot be explained by other conditions and is a synonym of persistent delusional disorder (F22.0 according to the ICD-10 classification) or shared DI (induced psychotic disorder F24.0), whereas secondary DI occurs due to various conditions such as depression, schizophrenia, dementia, stroke, diabetes, HIV infection, medical drugs intake (e.g. ciprofloxacin), drug abuse (cocaine) or vitamin deficiencies [411], to mention just a few. The bizarre nature of DI is supported by the “specimen sign” (formerly described as the “matchbox sign” in 1983) [12]. It is considered a classic feature of DI and denotes samples of suspected parasites or other factors being brought for analysis by the patients. “Specimen sign” is a more appropriate term than “matchbox sign” as it focuses on any kind of samples being brought for examination, not the receptacle [2]. Due to its rarity, to date, most data on DI have come from case reports or small cases series.

Aim

This study aimed to analyse clinical features of a group of 21 subjects with DI who were admitted to a tertiary dermatology ward in order to aid clinicians in successfully performing their diagnostic and therapeutic procedures in this challenging group of patients.

Material and methods

A retrospective descriptive analysis of DI patients hospitalized between 1997 and 2019 in the dermatology department was carried out based on the available documentation. The diagnosis of DI was established upon typical clinical features and psychiatric consultation. The emphasis was put on the duration of symptoms, psychiatric symptomatology (including the presence of the specimen sign), systemic comorbidities, follow-up visit attendance as well as the initiated treatment and associated outcome.

Results

The data regarding 21 consecutive patients were obtained. The mean age of subjects was 65.2 ±13.3 years (range: 39–89 years), with the majority being females (n = 16; 76.2%). Regarding marital status, 9 were married (42.8%), 6 were widowed (28.6%), 3 were single and 3 were divorced (14.3% each). The majority of subjects (n = 15; 71.4%) reported living with at least one family member, 6 lived alone (28.6%). Fifty-seven percent of patients (n = 12) reported that they had visited a psychiatrist at least once before current admission. Among those, depression, anxiety disorder, alcohol dependence, benzodiazepine dependence and adaptive reaction had bothered one subject each. Coexisting comorbidities encompassed arterial hypertension (n = 6; 28.6%), mild anaemia (n = 3; 14.3%), hypothyreosis, type II diabetes and implanted cardiac defibrillator due to arrhythmia (n = 2; 9.5% each), rheumatoid arthritis, atopic dermatitis and psoriasis (n = 1; 4.8% each). Before being referred to the dermatology ward, 8 (38.1%) patients were treated for suspected scabies infestation with permethrin or crotamiton. The mean duration of symptoms prior to admission was 1.9 ±1.7 years (range: 1 month – 5 years). All patients presented with a variety of skin lesions attributed to chronic scratching or attempts to remove the imaginary parasites (erythema, erosions, excoriations, crusts, hyperpigmentation, scars), usually located on the trunk and lower limbs (Figure 1). The specimen sign was present in 47.6% of cases (n = 10), usually consisting of dirt, sand, threads or debris presented in a plastic container (Figure 2). Among those, 3 patients also drew the images of the suspected causative factors on a piece of paper. Patients provided abundant verbal descriptions of suspected causative factors of their symptoms (Table 1), with worms (n = 11; 52.4%), unspecified parasites (n = 9; 42.9%), “something” (n = 7; 33.3%) and flies (n = 4; 19%) reported most commonly. The need of a psychiatric consultation by a dedicated psychiatrist was explained to all patients and each agreed to participate. Overall, a psychiatric consultation was performed in 20 (95.2%) patients (1 patient left the ward without informing medical personnel of his intentions before being consulted). Primary delusional disorder was diagnosed in 16 (76.2%) patients (F22.0), followed by shared delusional disorder (F24) and secondary delusional disorder of organic origin (2 patients each; 9.5%) (F06.2). Regarding the diagnosis of shared delusional disorder (folie a deux), 2 patients (a 79-year-old male and a 66-year-old female) were a married couple. The belief of infestation had started 5 years earlier in the woman. They expressed that the “worms” appeared because of the homeless person who periodically resided in the garden shed. The couple consulted dermatologists, parasitologists, veterinarians and entomologists. They applied household detergents to their skin which resulted in skin irritation. A disinfection of the apartment was performed thrice; the furniture was also removed.

Figure 1

Photographs of the clinical lesions in DI patients

/f/fulltexts/PDIA/37908/PDIA-38-37908-g001_min.jpg
Figure 2

The specimen sign

/f/fulltexts/PDIA/37908/PDIA-38-37908-g002_min.jpg
Table 1

Sociodemographic and clinical data of psoriasis patients (with and without depression) and healthy controls. Median value: 25–75%

ParameterPsoriasis patientsControl group
N = 98
Whole group
n = 110
BDI ≥ 12
n = 65
BDI < 12
n = 45
Age (mean ± SD)44.1 ±13.144.2 ±12.644.0 ±14.036.8 ±10.4*
Illness duration [years]16.0; 8.0–30.016.0; 6.0–30.016.0; 10.0–23.0
Duration of the current acute psoriasis episode [weeks]12.0; 6.0–16.08.0; 4.0–14.012.0; 8.0–16.0#
PASI19.6; 15.5–26.122.8; 16.8–29.517.4; 14.8–21.0#
BDI13.0; 9.0–18.023.0; 16.5–23.08.0; 5.0–10.0#4,0; 2.0–8.0**
IL-1 [pg/ml]0.9; 0.6–1.40.8; 0.5–1.30.9; 0.6–1.60.9; 0.6–1.3
IL-6 [pg/ml]1.6; 0.9–4.11.8; 1.1–6.41.6; 0.9–2.01.3; 0.6–2.3

[i] Difference between psoriasis patients and healthy controls significant at: *p < 0.05; **p < 0.001. Difference between psoriasis patients with and without depression significant at #p < 0.001. Mann-Whitney U test.

Risperidone was initiated in 61.9% of patients (n = 13), usually starting with 0.5–2 mg nightly, with a gradual dose increase. Among patients treated with risperidone, haloperidol monotherapy preceded treatment with risperidone in 1 patient, whereas unsuccessful olanzapine course was followed by instigating risperidone in the other patient. Other treatment modalities included perazine, promazine, haloperidol (in monotherapy or in combination with paroxetine) and chlorprothixene. Two (9.5%) patients refused to initiate treatment with risperidone. Unfortunately, only 7 patients (33.3% in total) attended the follow-up visit, whereas a partial remission of symptoms was observed in 5 of them (23.8% in total). One patient decided to discontinue risperidone due to adverse events (dizziness, tachycardia), while the other one due to no improvement of the symptoms perceived.

The summary of clinical data regarding the subjects is presented in Table 2.

Table 2

Correlations between subscales of TEMPS-A in psoriasis patients (Spearman’s rho)

TEMPS-ADepressiveCyclothymicHyperthymicIrritableAnxious
Depressive0.45*–0.40*0.53*0.68*
Cyclothymic0.45*–0.26*0.65*0.58*
Hyperthymic–0.40*–0.26*–0.32*–0.39*
Irritable0.53*0.65*–0.32*0.57*
Anxious0.68*0.58*–0.39*0.57*

* Correlation statistically significant at p < 0.05.

Discussion

To the best of our knowledge, this is the first report on DI among Polish patients involving such a big series of patients. DI is typically considered as a rare condition; nevertheless, our previous study suggests that it is commonly encountered in dermatological practice [13]. Approximately 85% of 118 dermatologists responding to the survey reported that they had seen at least 1 patient with DI during their practice. Frequently, the phenomenon of “doctor hopping” occurs. Patients attend various dermatologists, tropical disease specialists, as well as entomologists and microbiologists [2]. As reported in the present study, general practitioners and dermatologists often initiate topical treatment with anti-scabietic drugs. Occasionally, such treatment is instigated together with antipsychotics in order to gain patient’s trust. Usually, establishing the diagnosis does not pose any difficulties due to the characteristic clinical picture. The specimen sign mostly involves dirt particles, sand, debris, fragments of epidermis, hair or cloth threads stored in plastic jars or bags; drawings, photographs or videos may also be presented. It is a classical yet not mandatory sign of DI; its prevalence in our study (10 out of 21 patients; 47.6%) was similar to other reports [14, 15].

Treatment of DI is problematic as patients may refuse to take psychiatric drugs and do not attend the follow-up visits. To establish trustful rapport it is necessary to carefully examine the specimens brought by the patients [16]. This also includes dermoscopy [17]. Additionally, the physician might consider taking a biopsy if the patient expects it [18]. The latter solution is based on two conditions firmly explained to the patient: the biopsy site is chosen by the physician and the patient agrees to reconsider his/her beliefs if the results of histological examination do not support the presence of parasites. Tactile hallucinations, paraesthesias and pruritus are frequently experienced by the patients, yet paradoxically they may be considered physician’s “allies” as the instigation of “psychiatric” drugs relieves these bothersome symptoms. Thereby, the expectations of both the patient and the physician are met, despite critical differences in the views concerning aetiology of the symptoms. In extremely rare cases though, the symptoms in subjects initially diagnosed with DI would eventually turn out to be truly associated with parasites, e.g. with Limothrips cerealium (grain thrips) or Dryomyza formosa (intestinal myiasis) [19, 20].

Antipsychotics constitute the main therapeutic modality of DI, although in most cases it is difficult to convince patients to initiate such treatment. In our patients psychiatric consultation was performed in the presence of the dermatologist, which might have contributed to higher initial compliance to treatment. A lack of willingness to attend the psychiatric consultation and refusal to instigate or continue psychoactive medication stem from the lack of insight and criticism of the affected patients. These aspects are direct consequences of psychotic symptomatology, such as delusions and tactile sensations. A first-generation antipsychotic, pimozide (currently unavailable in Poland), has been studied in the literature featuring the largest number of DI patients so far [14, 21, 22]. The newer substances belonging to the second-generation (atypical) antipsychotics also act as dopamine receptor (D2) antagonists; however, their antagonism towards serotonin receptors (particularly the 5-HT2a) is more pronounced. Therefore, they still exert a high antipsychotic effect whilst reducing the risk of adverse events, such as the extrapyramidal syndrome [23, 24]. Currently, risperidone is considered as the drug of choice in DI [25]. The starting dose is usually 0.5–2 mg nightly, gradually increased to 4–8 mg/day. Notably, risperidone doses utilized in DI are usually smaller than in schizophrenia. A Japanese case report demonstrated a significant increase in regional cerebral blood flows in the bilateral frontal and left temporoparietal regions, the right parietal operculum and the bilateral basal ganglia after initiating risperidone in a patient with DI [26]. Compared to first-generation antipsychotics, risperidone is associated with a higher risk of metabolic syndrome, hyperprolactinemia and postural hypotension [24]. Moreover, an association with cerebrovascular incidents has also been observed in several studies among the elderly [2729], although this association is less pronounced than in patients treated with haloperidol or chlorpromazine [30] and similar to those using olanzapine or quetiapine [31]. Nevertheless, this drug should not be used in patients who underwent a stroke recently. Other atypical antipsychotics mentioned in case reports encompass aripiprazole (3.75–15 mg/day), olanzapine (2.5–10 mg/day), paliperidone (3 mg/day), quetiapine (25–50 mg/day), sertindole (4–12 mg/day) and ziprasidone (120 mg/day) [3239]. Unfortunately, long-term treatment with antipsychotics lasting from months or years is often necessary to maintain remission as early discontinuation of the drug following the initial success causes recurrence of symptoms.

Early instigation of treatment is relevant as the patients’ symptoms may intensify, resulting in a suicidal attempt and occasionally leading to death [40]. During the clinical interview DI patients often appear reluctant to cooperate and secretive while verbal and physical aggression towards medical personnel also occurs occasionally. Remarkably, there was a report of an elderly female with DI who attempted to shoot her doctor with a hunting gun (fortunately she missed) [41]. The paper also mentions a personal communication referencing an unpublished case of a female with DI who shot her physician after being suggested to visit a psychiatrist.

Conclusions

DI patients present mainly to dermatologists despite the psychiatric origins of the disease and feature a variety of bizarre clinical manifestations. Based on the literature and similarly to other delusional disorders, DI may be treated with antipsychotics, both first-generation and atypical. Currently, risperidone is considered the mainstay of treatment. Managing these patients remains a challenge and requires strict cooperation between dermatologists and psychiatrists.

Conflict of interest

The authors declare no conflict of interest.

References

1 

Jafferany M, Franca K. Psychodermatology: basics concepts. Acta Derm Venereol 2016; 96: 35-7.

2 

Freudenmann RW, Lepping P. Delusional infestation. Clin Microbiol Rev 2009; 22: 690-732.

3 

Trabert W. 100 years of delusional parasitosis. Meta-analysis of 1,223 case reports. Psychopathology 1995; 28: 238-46.

4 

Slaughter JR, Zanol K, Rezvani H, Flax J. Psychogenic parasitosis. A case series and literature review. Psychosomatics 1998; 39: 491-500.

5 

Aw DC, Thong JY, Chan HL. Delusional parasitosis: case series of 8 patients and review of the literature. Ann Acad Med Singapore 2004; 33: 89-94.

6 

Bhatia MS, Jagawat T, Choudhary S. Delusional parasitosis: a clinical profile. Int J Psychiatry Med 2000; 30: 83-91.

7 

Adunsky A. Early post-stroke parasitic delusions. Age Ageing 1997; 26: 238-9.

8 

Musso MW, Jones GN, Heck MC, Gouvier D. Delusional parasitosis as a presenting feature of HIV dementia: a case study. Appl Neuropsychol Adult 2013; 20: 66-72.

9 

Steinert T, Studemund H. Acute delusional parasitosis under treatment with ciprofloxacin. Pharmacopsychiatry 2006; 39: 159-60.

10 

Dunn J, Murphy MB, Fox KM. Diffuse pruritic lesions in a 37-year-old man after sleeping in an abandoned building. Am J Psychiatry 2007; 164: 1166-72.

11 

Aleshire I. Delusion of parasitosis: report of successful care with antipellagrous treatment. J Am Med Assoc 1954; 155: 15-7.

12 

Lee WR. Matchbox sign. Lancet 1983; 2: 457-8.

13 

Szepietowski JC, Salomon J, Hrehorów E, et al. Delusional parasitosis in dermatological practice. J Eur Acad Dermatol Venereol 2007; 21: 462-5.

14 

Zomer SF, De Wit RF, Van Bronswijk JE, et al. Delusions of parasitosis. A psychiatric disorder to be treated by dermatologists? An analysis of 33 patients. Br J Dermatol 1998; 138: 1030-2.

15 

Freudenmann RW, Lepping P, Huber M, et al. Delusional infestation and the specimen sign: a European multicentre study in 148 consecutive cases. Br J Dermatol 2012; 167: 247-51.

16 

Jeon C, Nakamura M, Koo J. Examining specimens brought in by a patient with delusional parasitosis. J Am Acad Dermatol 2018; 78: e1.

17 

Ladizinski B, Elpern DJ. Dermoscopy in delusions of parasitosis. Int J Dermatol 2013; 52: 838-9.

18 

Jeon C, Nakamura M, Koo J. The demand for skin biopsy from a patient with delusional parasitosis. J Am Acad Dermatol 2017; 77: e125.

19 

Guarneri F, Guarneri C, Mento G, Ioli A. Pseudo-delusory syndrome caused by Limothrips cerealium. Int J Dermatol 2006; 45: 197-9.

20 

Chigusa Y, Shinonaga S, Koyama Y, et al. Suspected intestinal myiasis due to Dryomyza formosa in a Japanese schizophrenic patient with symptoms of delusional parasitosis. Med Vet Entomol 2000; 14: 453-7.

21 

Hamann K, Avnstorp C. Delusions of infestation treated by pimozide: a double-blind crossover clinical study. Acta Derm Venereol 1982; 62: 55-8.

22 

Lindskov R, Baadsgaard O. Delusions of infestation treated with pimozide: a follow-up study. Acta Derm Venereol 1985; 65: 267-70.

23 

Elmer KB, George RM, Peterson K. Therapeutic update: use of risperidone for the treatment of monosymptomatic hypochondriacal psychosis. J Am Acad Dermatol 2000; 43: 683-6.

24 

Sandoz A, LoPiccolo M, Kusnir D, Tausk FA. A clinical paradigm of delusions of parasitosis. J Am Acad Dermatol 2008; 59: 698-704.

25 

Campbell EH, Elston DM, Hawthorne JD, Beckert DR. Diagnosis and management of delusional parasitosis. J Am Acad Dermatol 2019; 80: 1428-34.

26 

Narumoto J, Ueda H, Tsuchida H, et al. Regional cerebral blood flow changes in a patient with delusional parasitosis before and after successful treatment with risperidone: a case report. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30: 737-40.

27 

Wooltorton E. Risperidone (Risperdal): increased rate of cerebrovascular events in dementia trials. CMAJ 2002; 167: 1269-70.

28 

Brodaty H, Ames D, Snowdon J, et al. A randomized placebo-controlled trial of risperidone for the treatment of aggression, agitation, and psychosis of dementia. J Clin Psychiatry 2003; 64: 134-43.

29 

Shin JY, Choi NK, Jung SY, et al. Risk of ischemic stroke with the use of risperidone, quetiapine and olanzapine in elderly patients: a population-based, case-crossover study. J Psychopharmacol 2013; 27: 638-44.

30 

Shin JY, Choi NK, Lee J, et al. Risk of ischemic stroke associated with the use of antipsychotic drugs in elderly patients: a retrospective cohort study in Korea. PLoS One 2015; 10: e0119931.

31 

Finkel S, Kozma C, Long S, et al. Risperidone treatment in elderly patients with dementia: relative risk of cerebrovascular events versus other antipsychotics. Int Psychogeriatr 2005; 17: 617-29.

32 

Huang WL, Chang LR. Aripiprazole in the treatment of delusional parasitosis with ocular and dermatologic presentations. J Clin Psychopharmacol 2013; 33: 272-3.

33 

Rocha FL, Hara C. Aripiprazole in delusional parasitosis: case report. Prog Neuropsychopharmacol Biol Psychiatry 2007; 31: 784-6.

34 

Freudenmann RW, Schönfeldt-Lecuona C, Lepping P. Primary delusional parasitosis treated with olanzapine. Int Psychogeriatr 2007; 19: 1161-8.

35 

Bosmans A, Verbanck P. Successful treatment of delusional disorder of the somatic type or “delusional parasitosis” with olanzapine. Pharmacopsychiatry 2008; 41: 121-2.

36 

Freudenmann RW, Kühnlein P, Lepping P, Schönfeldt-Lecuona C. Secondary delusional parasitosis treated with paliperidone. Clin Exp Dermatol 2009; 34: 375-7.

37 

Milia A, Mascia MG, Pilia G, et al. Efficacy and safety of quetiapine treatment for delusional parasitosis: experience in an elderly patient. Clin Neuropharmacol 2008; 31: 310-2.

38 

Yorston G. Treatment of delusional parasitosis with sertindole. Int J Geriatr Psychiatry 1997; 12: 1127-8.

39 

De Berardis D, Serroni N, Marini S, et al. Successful ziprasidone monotherapy in a case of delusional parasitosis: a one-year follow-up. Case Rep Psychiatry 2013; 2013: 913248.

40 

Monk BE, Rao YJ. Delusions of parasitosis with fatal outcome. Clin Exp Dermatol 1994; 19: 341-2.

41 

Bourgeois ML, Duhamel P, Verdoux H. Delusional parasitosis: folie à deux and attempted murder of a family doctor. Br J Psychiatry 1992; 161: 709-11.

Copyright: © 2019 Termedia Sp. z o. o. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) License (http://creativecommons.org/licenses/by-nc-sa/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited and states its license.
 
Quick links
© 2024 Termedia Sp. z o.o.
Developed by Bentus.