Psychol Res Behav Manag. 2018; 11: 425–432.
Published online 2018 Oct 1. doi: 10.2147/PRBM.S166720
Reframing delusional infestation: perspectives on unresolved puzzles
Jianbo Lai,1,2,3 Zhe Xu,4,5 Yi Xu,1,2,3 and Shaohua Hu1,2,3
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Delusional infestation (DI), a debilitating psychocutaneous condition, featured as a false fixed belief of being infested accompanied by somatosensory abnormality, behavior alteration, and cognitive impairment. Although management of primary causes and pharmacotherapy with antipsychotics and/or antidepressants can help to alleviate symptoms in most patients, the underlying etiology of DI still remains unclear. Morgellons disease (MD), characterized by the presence of cutaneous filaments projected from or embedded in skin, is also a polemic issue because of its relationship with spirochetal infection. This review aims to discuss the following topics that currently confuse our understandings of DI: 1) the relationship of real/sham “infestation” with DI/MD; 2) behavior alterations, such as self-inflicted trauma; 3) neuroimaging abnormality and disturbance in neurotransmitter systems; and 4) impaired insight in patients with this disease. In discussion, we try to propose a multifactorial approach to the final diagnosis of DI/MD. Future studies exploring the neurobiological etiology of DI/MD are warranted.
Keywords: delusional infestation, Morgellons disease, behavior, neurotransmitter, insight
Delusional infestation (DI) is an uncommon, intricate psychocutaneous condition.1 Against available medical evidence, patients with DI have a strong conviction that they are infested with little animals or less frequently inanimate matter.1,2 Meanwhile, patients always complain of abnormal skin sensations, such as stinging, biting, and crawling, which were ascribed to the “infestation”. The symptoms of DI can occur as primary, or more commonly, secondary to diverse medical conditions, such as neuropsychiatric diseases, nutrient deficiency, psychotropic medications, infections, intoxication, tumors, and metabolic disturbance.3 Etiology-dependent management and antipsychotics/antidepressants have been reported to be therapeutically effective.1,3,4
Worldwide retrospective researches and case reports have painted an inexplicit epidemiological picture of DI.5–7 In clinical practice, DI might be underdiagnosed as patients are always reluctant to psychiatric referral and prefer to visit dermatologists, microbiologists, and general practitioners. The prevalence of appropriately 80 cases per million was reported in private practices, while much less cases were presented and identified in public health services (appropriately 5.5 cases per million).8 Middle-aged to elderly women, especially those with inadequate social contact, are more likely to be afflicted.5–8 The duration of illness can be less than 1 year or as long as three decades.3 However, the final diagnosis and proper management of DI are always delayed.
To date, there are still many puzzles hindering our in-depth understanding of somatosensory abnormality, behavior alteration, and cognitive impairment in DI. 1) Are symptoms associated with DI simply delusional? Can real infestation cause DI-like symptoms? 2) How to unscramble the behavior pattern in DI patients, such as self-inflicted skin trauma? 3) Antipsychotics and/or antidepressants are generally effective in managing symptoms of DI. This phenomenon indicates disturbance in neurotransmitter systems according to the pharmacological actions of agents. Moreover, recent advances in neuroimaging researches of DI patients need to be updated, including brain anatomical and functional abnormalities. 4) Patients with DI commonly lost their insight of disease nature. Whether their insight can be restored after improvement in symptoms? A better characterizing of aforementioned puzzles is of significant importance in clinical practice and fundamental research.
Herein, we start with expounding the current knowledge of above puzzles. In the “Discussion” section, we try to propose a multifactorial approach, which helps to facilitate the diagnosis of DI/Morgellons disease (MD).
Sham or real infestation
This question should be prudently answered, as it directly determines the nature of DI. To date, a great many of animate pathogens have been blamed, including all kinds of arthropods, worms, bacteria, and fungi.8 These pathogens are always described as small and vivid. In contrast, inanimate matter, long and thin, such as fibers, threads, hair, and the like, is less frequently reported.9 A comprehensive review of different “pathogens” is listed in Figure 1.10–23 The specific type of alleged pathogen by certain patient could be affected by one’s own knowledge, life experience, and living environment. These pathogens might be wrapped with containers, referred to as the “specimen” or “matchbox” sign,3 and taken to clinic or hospital as an evidence of infestation. For most of the time, however, microscopy or even skin biopsy fails to find out the alleged pathogenic agent. In addition, the abnormal skin sensations, such as stinging, crawling, biting, and pinching, intensify patients’ belief of infestation. In DI patients, abnormal activation of an itch pathway from the skin to the central nervous system is suspected.16 Dysfunction of interoception, improper processing, and misinterpretation of perceived sensations contribute to the formation of tactile or even visual hallucinations. Of note, it seems that delusions are always infestation oriented and, apart from infestation, the individuals’ function well in other life scenes.
More at this link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6171510/
Hey CDC did you see this one? You are looking really stupid!