Delusions of parasitosis: a brief review of the literature and pathway for diagnosis and treatment

Abstract

A large proportion of patients seen in dermatology practices have underlying psychological issues associated with their skin diseases. One of the most flagrant examples of this are patients with delusions of parasitosis. These patients have false fixed beliefs that they are infested by parasites and experience cutaneous sensations of crawling, biting, and stinging associated with their delusions. There is no organic skin disorder and all cutaneous manifestations are self-induced. Rather than a psychiatrist, the dermatologist is often designated by the patient to handle the chief complaint, even though the main disorder is psychogenic. In spite of their limited evidence, antipsychotic medications have become the mainstay of therapy for delusions of parasitosis. The dermatologist must therefore be familiar with the approach to diagnosis and the use of antipsychotic or neuroleptic medications, which usually reside in the domain. There are few clinical trials and no substantial randomized controlled trials examining the efficacy of the psychiatrist antipsychotic medication used to treat delusions of parasitosis. This review article synthesizes the current available research and distils it down to analyzes 17 case reports, comprising 37 cases, examining the use of risperidone and olanzapine in the treatment of delusions of parasitosis. These findings are synthesized into a clinical pathway designed to assist dermatologists in effectively managing patients with delusions of parasitosis.