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MD is a type of delusional parasitosis where patients report that their skin contains parasites, toxins, fibers, or other foreign material.

Advertisement | Articles | November 1, 2022 Morgellons Disease: A Mysterious Disease Author(s)Charmaine Yuan , Bernard A. Cohen, MD MD is a type of delusional parasitosis where patients report that their skin contains parasites, toxins, fibers, or other foreign material. Introduction Morgellons disease (MD) was first described in 1674 in a letter by Sir Thomas Browne, describing a pediatric skin disease characterized by “harsh hairs on…backs.” Later case studies described “parasitophobias,” “delusions of parasitosis,” or “dermatological hypochondriasis,” and some physicians reported an association of delusional parasitosis with spirochetal infection. The first case of MD as currently defined was described by biologist Mary Leitao in 2001, who noticed nonhealing lesions on her son which were found to have blue and red filaments embedded1. However, MD is a poorly understood condition, with no consensus on its classification as a medical or psychiatric condition, pathophysiology, or treatment2. Clinical Features MD is a type of delusional parasitosis where patients report that their skin contains parasites, toxins, fibers, or other foreign material3. They may also experience a sensation of crawling, biting, or stinging4. Patients often present with nonhealing lesions such as excoriations, which are self-inflicted as patients attempt to remove whatever is in their skin3. Lesions are usually not found in hard-to-reach areas, like the mid-back, and some patients will bring a collection of specimens that they have removed from their skin (“matchbox sign”) to their physician. MD most commonly affects middle-aged, Caucasian females5. Younger patients tend to be of lower socioeconomic status and often have a history of substance abuse. It may also manifest as a shared delusional disorder with close contacts, particularly family members, accepting the same delusions6. There is no standard clinical classification scheme for MD, though one has been proposed: Early localized: lesions present for less than 3 months, localized to one area of the body (head, trunk, extremities) Early disseminated: less than 3 months, more than one area Late localized: more than 6 months, one area Late disseminated: more than 6 months, more than one area1. Pathophysiology In 2012, the Centers for Disease Control (CDC) conducted the first and most comprehensive study of patients with MD. Researchers did not find a pattern of epidemiological or clinical features consistent with an infectious etiology. Analysis of sample material found that the most common components were protein and cellulose, consistent with skin and textile fibers. A correlation was also seen with psychiatric comorbidity, as well as psychoactive drug use. Many later studies confirmed these findings, supporting a psychiatric cause2. MD may be considered a group conversion disorder, or mass psychogenic illness, as the internet allows information/misinformation to spread as patients look for an explanation for their symptoms3. However, an article by Middelveen et al. argues against a delusional etiology for MD, as many studies included cases that did not meet DSM-V criteria for delusional disorder (diagnosis could be better explained by another medical/mental disorder) and a lack of fiber analysis and Lyme serologic testing. Some histologic studies of filaments have found that they are not textile fibers but biofilaments made of keratin and collagen, produced by activated keratinocytes and fibroblasts, or melanin. They also argue that electron microscopy has shown that the fibers were too deeply embedded to be self-implanted1. Some studies state that MD is a cutaneous manifestation of spirochetal infections, particularly Lyme disease (LD), based on culture, histopathological, and molecular evidence2. A study with subjects with confirmed presence of fibers embedded in or projecting from skin found that most patients had LD as well. Several other studies have also found Borrelia spirochetes in skin specimens from MD patients1. However, the CDC study did not identify any borrelial etiology. While cultures were not collected from all subjects, the sample size was large and such a positive association between LD and MD, if it existed, should have been detected2. Another argument against a spirochetal etiology is that the studies that found a correlation were conducted by the same study group; independent researchers have yet to replicate those results2. A study reviewing functional and structural imaging studies found that MD may have an organic etiology, as patients were found to have dysfunction in the fronto-striato-thalamo-parietal network (leading to false perceptions of pruritis and infestation, impaired judgment, inability to interpret false sensations) and increased activation of structures involved in itch processing. In secondary MD, patients were found to have ischemic changes in areas that control visuo-tactile perception4. Treatment There is a lack of data from randomiz...

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