A systematic literature review on delusional parasitosis

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.

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.

The Global Prevalence of Primary Psychodermatologic Disorders: A Systematic Review

The management of primary psychodermatologic disorders (PPDs) (i.e., psychiatric disorders with dermatologic presentation) is challenging. The scarceness of reported prevalence hinders the development of coordinated interventions to improve healthcare delivery. This review aimed to explore the global prevalence of PPDs. The review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement. Of the 4632 identified publications, 60 were included. Five PPDs were investigated from the included studies: delusional parasitosis (n=9), skin picking disorder (n=26), trichotillomania (n=22), tanning dependence (n=5), and repetitive nail biting (n=6). Delusional parasitosis was rare in the general population (prevalence ranging from 0.0002% to 0.03%), with higher rates in the psychiatric settings (outpatient=0.5%; inpatient=0.1%). Other pathologic or subclinical forms of PPDs had a minimum prevalence of 0.3% (median=7.0%; mean=17.0%). The distribution of the prevalence rates was highly skewed, with large differences based on the study setting (e.g., dermatologic settings, psychiatric settings, and general population). The most common condition was pathologic skin picking (prevalence, 1.2%-11.2%) in the general population. Its rates were higher in the psychiatric settings (obsessive-compulsive disorder, 38.5%; Tourette syndrome, 13.0%; body dysmorphic disorder, 26.8%-64.7%). The prevalence of trichotillomania in the general population ranged from 0.6% to 2.9%, while that of pathologic tanning and nail biting could not be ascertained as the studies were mainly in students (range; 12.0%-39.3% and 3.0%-10.1%, respectively). In conclusion, PPDs are common, especially in the dermatologic and psychiatric settings. Further population-based studies are needed to determine more accurate prevalence rates.

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.

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.

Coexistence of Primary and Secondary Delusional Parasitosis

Objective

Delusional parasitosis (DP) is a difficult-to-treat condition. It is prevalent in all cultures, societies, and countries. Previous case reports of DP have been published; however, the patient presented in this report is unique because of the co-occurrence of both primary and secondary types of DP. We aim to explore the two subtypes of DP.

Conclusions

We discuss DP from a nosological perspective and also highlight the various theories at play in the pathogenesis of primary and secondary DP. The different subtypes of DP should be taken into consideration as they also have a bearing on the management.

Delusions of Parasitosis: An Update

Delusional parasitosis, also known as delusional infestation or Ekbom syndrome, is a relatively infrequent psychotic disorder characterized by an unwavering false belief that there is a parasitic infestation of the skin, despite the absence of any medical evidence that could support this claim. Delusional parasitosis can be categorized into primary, secondary, and organic forms. Sometimes, close relatives also experience identical delusions. This phenomenon was reported to occur in 5-15% of cases, and is known as shared psychotic disorder-delusional parasitosis with folie à deux. Patients with delusional parasitosis frequently seek help from many physicians. Close multidisciplinary cooperation between clinicians is often key to shortening the time taken to diagnose this disorder. Initiation of psychopharmacological therapy is a challenge, as many patients refuse any psychiatric treatment because of the stigma associated with mental illness and because of their firm belief that they have a parasitic infestation, not a psychiatric condition. For many patients, a sense of a lack of understanding leads to isolation and the development of depression symptoms, which is why it is crucial to earn the trust of such patients while taking care of them.