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.