Delusions of parasitosis

Delusional infestation treated with risperidone: a series of 27 patients

BACKGROUND

Patients with delusional infestation (DI) frequently refuse to be treated with psychoactive drugs. In the past, pimozide was commonly used as a first-line agent but is now prescribed more rarely. Risperidone was first used to treat DI in 1995. A recent review identified 12 studies that evaluated the use of risperidone in 43 patients with DI.

OBJECTIVES

To study the characteristics of and therapeutic results in patients with DI treated with risperidone at a university medical centre in São Paulo, Brazil.

METHODS

We performed a retrospective study of patients with DI treated with risperidone at a dermatological university clinic since 2016. Records were reviewed for personal data and findings related to treatment.

RESULTS

Twenty-seven patients were studied (20 women and 7 men). The maintenance dose of risperidone varied from 1 mg three times weekly to 8 mg daily. Control of symptoms was achieved in the majority of patients. A reduction in dosage due to side-effects was seen in four patients; risperidone had to be switched to another antipsychotic in three cases, despite a good response. Only one patient did not respond to risperidone.

CONCLUSIONS

Risperidone is an effective, well-tolerated and safe treatment for delusional parasitosis. Adequate follow-up is mandatory in order to obtain long-term control of symptoms.

Insights into the Medical Evaluation of Ekbom Syndrome: An Overview

Ekbom syndrome, also known as delusional parasitosis (DP) or delusional infestation, is an uncommon psychiatric disorder distinguished by an enduring conviction of parasitic infestation, persisting notwithstanding the presence of medical evidence to the contrary. Primarily affecting middle-aged women, DP can manifest either as isolated psychological distress or as a component within a more intricate psychiatric framework, substantially influencing the quality of life for affected individuals. Its pathophysiological mechanism involves uncertain dopaminergic imbalances and dysfunction in the dopamine transporter system. Dermatologists often play a pivotal role in diagnosis, as patients first seek dermatological assessments of their signs and symptoms. However, DP frequently originates from underlying psychiatric disorders or medical variables, manifesting with neurological and infectious causative factors. The diagnostic complexity is attributed to patients' resolute convictions, leading to delayed psychiatric intervention. First-line DP treatment involves antipsychotics, with newer agents demonstrating promising prospects, but the lack of standardized protocols poses a significant therapeutic challenge. In this narrative review, both a comprehensive approach to this uncommon pathology and an update on the state of knowledge in this medical subfield focused on optimizing the management of DP are provided. The complexity of DP underlying its uncommon nature and the incomplete understanding of its pathophysiology highlight the need for further research through multicenter studies and multidisciplinary teams to enhance therapeutic efficacy and safety.

The Diagnostic Workup, Screening, and Treatment Approaches for Patients with Delusional Infestation

Delusional infestation (DI) is a psychiatric disorder defined by the fixed, false belief that one has been infested by an organism without evidence to support this. Patients may present with skin lesions and report abnormal cutaneous sensations. The diagnostic workup for patients presenting with delusional infestation is essential to ensuring accurate diagnosis in ruling out other explanations for symptoms and investigating potential secondary causes of DI. In addition to a comprehensive history and physical examination, laboratory workup should be considered depending on the clinical picture. Antipsychotic medications are the most common drugs used in management of adults with DI and tailor the choice of treatment according to patient characteristics. This article serves as a guide for dermatologists, psychiatrists, and other clinicians as it reviews the workup and screening that should be considered when managing a patient with delusional infestation and subsequent treatment protocols once the diagnosis has been made.

Mucocutaneous alterations and complications in amphetamine abusers: a narrative review

Amphetamines are the second most commonly used illicit drug worldwide. Amphetamine use can result in significant cutaneous morbidity. This review highlights the dermatological manifestations of amphetamine abuse.

Right frontal meningioma presenting as delusional parasitosis

Central nervous system tumours can occasionally present with psychiatric symptoms as the only manifestation and can often pose diagnostic challenges. A man in his early 60s presented to the psychiatry outpatient department with delusional parasitosis. His old age and an episode of urinary and faecal incontinence made the clinician consider neuroimaging at the very first visit itself. He was detected to have a right frontal meningioma with features of intracranial hypertension with midline shift, and he underwent emergency surgery. His delusional symptoms completely resolved after surgery and did not recur during the follow-up period of 2.5 years. A right frontal meningioma presenting as delusional parasitosis has probably not been reported in the literature before, and the case is being reported to highlight the rarity of its presentation, the importance of eliciting a detailed clinical history and the need for early neuroimaging in these cases.

The Potential Uses of N-acetylcysteine in Dermatology: A Review

Background: In recent studies, N-acetylcysteine has been shown to be efficacious in several dermatologic conditions. Objective: The aim was to review clinical trials that assess the efficacy of N-acetylcysteine in cutaneous disorders. Design: The PubMed database was searched and a manual search of clinical trials in the references was performed. Studies included randomized, controlled studies, uncontrolled studies, meta-analyses, and systemic reviews published between years 1966 and 2017. Results: Efficacy of N-acetylcysteine was shown in excoriation disorder, onychophagia disorder, trichotillomania, acne vulgaris, Type I lamellar ichthyosis, bullous morphea, systemic sclerosis, toxic epidermal necrolysis, atopic dermatitis, xeroderma pigmentosum, and pseudoporphyria. Studies also show benefits in wound healing and photoprotection. Conclusion: The review of available literature suggests that N-acetylcysteine could potentially serve as a safe, tolerable, and effective therapeutic option for a variety of dermatologic conditions.

History of Morgellons disease: from delusion to definition

Morgellons disease (MD) is a skin condition characterized by the presence of multicolored filaments that lie under, are embedded in, or project from skin. Although the condition may have a longer history, disease matching the above description was first reported in the US in 2002. Since that time, the condition that we know as MD has become a polemic topic. Because individuals afflicted with the disease may have crawling or stinging sensations and sometimes believe they have an insect or parasite infestation, most medical practitioners consider MD a purely delusional disorder. Clinical studies supporting the hypothesis that MD is exclusively delusional in origin have considerable methodological flaws and often neglect the fact that mental disorders can result from underlying somatic illness. In contrast, rigorous experimental investigations show that this skin affliction results from a physiological response to the presence of an infectious agent. Recent studies from that point of view show an association between MD and spirochetal infection in humans, cattle, and dogs. These investigations have determined that the cutaneous filaments are not implanted textile fibers, but are composed of the cellular proteins keratin and collagen and result from overproduction of these filaments in response to spirochetal infection. Further studies of the genetics, pathogenesis, and treatment of MD are warranted.

Postherpetic Neuralgia Presenting as Delusional Parasitosis: A Case Series

Delusional parasitosis (DP) or Ekbom's disease is a rare psychiatric condition where the sufferers have a firm-fixed belief of insects crawling over their skin. The condition may be primary monosymptomatic hypochrondrical delusion or secondary to an underlying psychiatric or organic condition. We present two cases of elderly men presenting with classical symptomatology of DP, which is found to be secondary to postherpetic neuralgia following an acute episode of shingles or herpes zoster infection. One patient responded to a combination of antipsychotic, olanzapine, and pregabalin, used for neuropathic pain, and the other patient responded completely with medications used for neuropathic pain only without any antipsychotic use.

Drug-Induced Tactile Hallucinations Beyond Recreational Drugs

In monosymptomatic hypochondriacal psychosis (MHP), such as delusional infestation (DI), the patient has a fixed, false, encapsulated belief associated with tactile hallucinations (TH), most commonly formication, which is defined as cutaneous sensations of crawling, stinging, biting, etc., without evidence of infestation. Drug-induced TH should be considered in patients with suspected MHP. Although recreational drugs such as cocaine, amphetamines, and narcotics are well known to induce TH, many busy practicing dermatologists may not be familiar with other types of medications that can induce TH. A literature search for peer-reviewed articles was conducted in the PubMed, PsychInfo, Cochrane, and Embase databases. For each article, the medication(s) that induced TH was identified in a systematic way. The most commonly reported group of medications to induce TH was anti-Parkisonian agents, followed by antidepressants, prescription stimulants, antihypertensives (propranolol), and antiepileptics. In many cases, other types of hallucinations, such as visual and auditory, were present. Patients also commonly presented with psychiatric comorbidities. Although the conclusions that can be derived from this literature review are limited, it appears that certain medications that alter neurotransmitters, especially dopamine and, less convincingly, norepinephrine and serotonin, can be associated with TH. Drug-induced TH should also be considered in patients presenting with multiple types of hallucinations and patients with existing psychiatric comorbidity. Drug-induced TH, especially with an underlying psychiatric diagnosis that is separate from MHP, may be a more manageable disease entity compared with bona fide MHP.

Folie a deux and delusional disorder by proxy: an atypical presentation

Delusion of parasitosis is a rare condition characterised by an individual harbouring the delusion of being infested with insects or parasites. We report a rare and interesting case of delusion of parasitosis presenting as folie a deux, that is, the delusion is shared by both the parents of an 18-month-old child, with proxy projection of parental delusion on the child. The case highlights the rare concomitant occurrence of two psychocutaneous disorders and emphasizes the importance of early recognition and appropriate intervention to safeguard the well-being of the child.

Children with a mother with delusional infestation--implications for child protection and management

Delusional infestation (DI) is a reportedly uncommon psychocutaneous condition in which an individual holds a fixed, false belief of pathogenic infestation of the skin or body contrary to medical evidence. There are reports of such a delusion being shared with family members or close friends (folie a deux/famillie), but the implications of DI induced in children have not been discussed. We describe the case of a mother with DI whose children subsequently shared her belief. Implications for child protection and management are explored.

Information, consent and treatment of patients with Morgellons disease: an ethical perspective

Morgellons is a medically contested diagnosis with foremost dermatological symptoms. Patients experience fibers emerging from the skin, together with a range of other somatic, psychiatric, and neurological complaints. Within the medical community, it is generally held to be a variation of delusional parasitosis/delusional infestation, which is usually treated with antipsychotics. Little attention has been paid in the literature to the ethical aspects of treating patients with Morgellons disease. The communicative strategies suggested in the literature display significant ethical issues, primarily the use of therapeutic privilege, i.e. withholding information from the patient. Since this limits patient autonomy, that approach is ethically problematic. Instead, the physician has an ethical obligation to respect the patient's autonomy, provide full information, and seek consent before initiating a psychiatric referral.