R. Taylor

Delusional parasitosis: time to call it delusional infestation

Delusional parasitosis (DP) is a term that was coined by Wilson and Miller in 1946 to describe a particular psychocutaneous clinical picture which had previously been called by various names. The well-recognized clinical picture of DP is reportedly an uncommon condition. Patients with DP hold a fixed belief that they are infected with organisms such as unicellular parasites, bacteria, viruses and worms; or infested with insects; or infiltrated by organic and nonorganic fibres, threads, ‘stealth viruses’ or other forms of inanimate particles known or unknown by medical science. We would like to support the change in the name proposed by Freudenmann and Lepping from ‘delusional parasitosis’ to the all-encompassing term ‘delusional infestation’ (DI). This term better reflects the growing number of patients who do not believe they are infested by ‘parasites’, covers any species blamed by patients for their symptoms, and includes the so-called ‘Morgellons syndrome’. The condition has been known by a variety of names since its initial description as ‘acarophobie’ in 1894 by Thieberge: these include ‘Dermatozoenwahn’ (Ekbom’s syndrome), delusion of infestation and parasitophobia. ‘Delusional parasitosis’ (the term preferred by many up until now) has been a more accurate term than parasitophobia as it is a true delusion, i.e. a fixed false belief, rather than a phobia (a persistent irrational fear). The diagnosis of DI can be subdivided into primary and secondary disorders. Primary functional delusional disorder is classified in DSM-IV-TR as delusional disorder somatic type and in ICD-10 as persistent delusional disorder. Nevertheless, the predominant delusional theme for most is that of an infestation. Some patients also see this as an infection or infiltration of one’s own body or immediate environment. We therefore prefer the term DI as it includes patients with a delusional belief that they are infected with any kind of vivid and inanimate pathogen. The basic phenomenology of the disease has remained unchanged for centuries, but as with most psychiatric disorders, the exact nature of the patients’ presentation is context dependent and changes over time. The term DI captures all the various presentations and, what is more, it is open to all future kinds of pathogens and infesting species which will (no doubt) emerge. Although reportedly uncommon, the average dermatologist will see two to three patients with DI every 5 years. The annual incidence of DI has been estimated at 20 cases per million. The female to male ratio under the age of 50 years is equal but over the age of 50 years the incidence is reported as 2 : 1. There is a bimodal distribution with a peak between 20–30 years and another at > 50 years, and there are frequent reports of the delusions being shared with a relative or close friend (folie à deux; 8–12% of cases of DI), and occasionally more than one person. It is likely that the incidence and prevalence of DI have been systematically under-reported. Clinicians who set up clinics for patients with DI and related disorders are soon inundated with patients who have hitherto been ‘held’ in primary care, or have ‘doctor-shopped’ so much that there is no one clinician who holds clinical responsibility for the patient. In many cases the aetiology is unknown. It may follow a real infestation, be associated with recreational drug use (especially alcohol, amphetamines, cannabis and cocaine), be a dementia-related psychosis in the elderly, and be associated with other organic disease. The management of patients with DI can be challenging. Treatment of secondary DI should begin with treating (where possible) underlying causes, in addition to treating the delusion itself. For example, it is important to treat any recreational drug and alcohol abuse as well as treating the patient’s skin and the delusion. Treatment of the skin as well as the psychiatric disease is crucial, not least because that is usually the patient’s main focus. Randomized controlled trials in the treatment of the delusion itself are lacking in part due to the nature of the condition and the obvious difficulty of recruiting patients for trials with informed consent. When referred to a purely psychiatric clinic, patients with DI will often default their appointments. Conversely, it is also difficult to manage these patients in a standard dermatology clinic as they often take considerable time and other resources to engage in therapeutic management. Lepping and coworkers conducted a systematic review of the effectiveness of antipsychotics in primary DI, and concluded that there was weak evidence that they are effective as there are no randomized controlled clinical trials. They describe the difficulties encountered by those trying to study pharmacological management of this group of patients. Healy et al. have reported a recent U.K. audit of the use of atypical antipsychotics in the treatment of DI. These authors report successful treatment of DI with atypical antipsychotics (often risperidone in surprisingly low doses, for example 0Æ5– 1 mg daily) in up to 75% of patients with DI. Patients who respond to second generation antipsychotics will usually start to describe benefit in their symptoms after 4–6 weeks of treatment, but the treatment will usually need to be continued for 6 months to 1 year. In the absence of evidence-based data there is some rationale in using atypical antipsycotics as first generation antipsychotics (for example, pimozide) may be

Insecure attachment and frequent attendance in primary care: a longitudinal cohort study of medically unexplained symptom presentations in ten UK general practices

BACKGROUND In primary care frequent attenders with medically unexplained symptoms (MUS) pose a clinical and health resource challenge. We sought to understand these presentations in terms of the doctor-patient relationship, specifically to test the hypothesis that such patients have insecure emotional attachment. METHOD We undertook a cohort follow-up study of 410 patients with MUS. Baseline questionnaires assessed adult attachment style, psychological distress, beliefs about the symptom, non-specific somatic symptoms, and physical function. A telephone interview following consultation assessed health worry, general practitioner (GP) management and satisfaction with consultation. The main outcome was annual GP consultation rate. RESULTS Of consecutive attenders, 18% had an MUS. This group had a high mean consultation frequency of 5.24 [95% confidence interval (CI) 4.79-5.69] over the follow-up year. The prevalence of insecure attachment was 28 (95% CI 23-33) %. A significant association was found between insecure attachment style and frequent attendance, even after adjustment for sociodemographic characteristics, presence of chronic physical illness and baseline physical function [odds ratio (OR) 1.96 (95% CI 1.05-3.67)]. The association was particularly strong in those patients who believed that there was a physical cause for their initial MUS [OR 9.52 (95% CI 2.67-33.93)]. A possible model for the relationship between attachment style and frequent attendance is presented. CONCLUSIONS Patients with MUS who attend frequently have insecure adult attachment styles, and their high consultation rate may therefore be conceptualized as pathological care-seeking behaviour linked to their insecure attachment. Understanding frequent attendance as pathological help seeking driven by difficulties in relating to caregiving figures may help doctors to manage their frequently attending patients in a different way.

Delusional infestation and the specimen sign: a European multicentre study in 148 consecutive cases.

Background  Systematic studies of delusional infestation (DI), also known as delusional parasitosis, are scarce. They lack either dermatological or psychiatric detail. Little is known about the specimens that patients provide to prove their infestation. There is no study on the current presentation of DI in Europe.

Three cases of delusional parasitosis caused by dopamine agonists

We report three cases of delusional parasitosis (DP) in patients with well‐established Parkinson’s disease, all of whom were taking dopamine agonists. In all three cases, the DP resolved rapidly when the drug was withdrawn.

Dermatitis artefacta and artefactual skin disease: the need for a psychodermatology multidisciplinary team to treat a difficult condition.

Dermatitis artefacta (DA) is a factitious skin disorder caused by the deliberate production of skin lesions by patients with a history of underlying psychological problems. The patient may not be fully aware of this, and the true extent of this disorder, especially in children, is currently unknown. Management of these patients is challenging as many fail to engage effectively with their dermatologist.

Management of patients with delusional parasitosis in a joint dermatology/ liaison psychiatry clinic

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Delusional infestation with unusual pathogens: a report of three cases

Delusional infestation (DI) is a psychiatric disorder characterized by a fixed, false belief that the patient is infested with extracorporeal agents. It is known by several names, including the more commonly used term ‘delusional parasitosis’. The psychiatric disease is responsible for the cutaneous pathology. About 90% of patients with DI seek help from dermatologists, and most reject psychiatric referral. Thus, effective management requires incorporation of psychiatric principles. We report three cases of DI with inanimate materials, and examine ‘Morgellons’ disease. We believe that patients with unusual presentations of DI are likely to be seen more commonly in the future. These patients appear to be a subgroup of DI, and may be even more difficult to treat than other patients with DI.

Sensations of skin infestation linked to abnormal frontolimbic brain reactivity and differences in self-representation

Some patients experience skin sensations of infestation and contamination that are elusive to proximate dermatological explanation. We undertook a functional magnetic resonance imaging study of the brain to demonstrate, for the first time, that central processing of infestation-relevant stimuli is altered in patients with such abnormal skin sensations. We show differences in neural activity within amygdala, insula, middle temporal lobe and frontal cortices. Patients also demonstrated altered measures of self-representation, with poorer sensitivity to internal bodily (interoceptive) signals and greater susceptibility to take on an illusion of body ownership: the rubber hand illusion. Together, these findings highlight a potential model for the maintenance of abnormal skin sensations, encompassing heightened threat processing within amygdala, increased salience of skin representations within insula and compromised prefrontal capacity for self-regulation and appraisal.

A study of service provision in psychocutaneous medicine

Psychocutaneous medicine concerns the recognition and treatment of psychological distress and psychiatric morbidity associated with dermatological diseases. A study in 2004 examining resources in the UK highlighted a number of deficiencies, and recommended that psychodermatology services be available, at least regionally, in the UK. Although there is now increased recognition of psychodermatology, this study of the availability of these services shows that provision has deteriorated since 2004.

Psychodermatology in Clinical Practice: Main Principles.

Psychodermatology is a newer and emerging subspecialty of dermatology, which bridges psychiatry, psychology, paediatrics and dermatology. It has become increasingly recognised that the best outcomes for patients with psychodermatological disease is via a multidisciplinary psychodermatology team. The exact configuration of the multidisciplinary team is, to some extent, determined by local expertise. In addition there is a growing body of evidence that it is much more cost effective to manage patients with psychodermatological disease in dedicated psychodermatology clinics. Even so, despite this evidence, and the demand from patients (and patient advocacy groups), the delivery and establishment of psychodermatology services is very sporadic globally. Clinical and academic expertise in psychodermatology is emerging in dermatology and other (often peer-reviewed) literature. Organisations such as the European Society for Dermatology and Psychiatry champion clinical and academic advances in psychodermatology, whist also enabling training of health care professionals in psychodermatology. Emiliano Panconesi, to whom this supplement is dedicated, was at the forefront of psychodermatology research and was a founding member of ESDaP.