Reframing delusional infestation: perspectives on unresolved puzzles

Jianbo Lai,1–3 Zhe Xu,4,5 Yi Xu,1–3 Shaohua Hu1–3 1Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; 2The Key Laboratory of Mental Disorder’s Management in Zhejiang Province, Hangzhou 310003, China; 3Brain Research Institute of Zhejiang University, Hangzhou 310003, China; 4Zhejiang University School of Medicine, Hangzhou 310003, China; 5Department of Psychiatry, Third People’s Hospital of Huzhou, Hangzhou 313000, China Abstract: 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, insigh