Tales of bugs, delusions of parasitosis, and what to do.

Delusions of parasitosis are usually a monosymptomatic dermatopsychiatric disorder manifested by the fixed false belief that insects are crawling over the body producing an intractable itch. Also known as parasitophobia, this disease can also be associated with other psychiatric disorders, such as schizophrenia or obsessive compulsive disorders. In most cases, the delusion is encapsulated and other mental functions remain intact. Parasitophobia is usually seen in middle-aged women and has proven a vexing problem for dermatologists to treat because patients are often reluctant to obtain a psychiatric consultation and wary of taking antipsychotic or antidepressant medication. Four patients with this disorder illustrate the problem, provide a new approach to understanding the precipitating factors in the onset of the disease, and permit the introduction of a previously undescribed therapy, escitalopram (Lexapro, Forest Pharmaceuticals, New York, NY), a selective serotonin reuptake inhibitor with less side effects than the previously favored therapy with pimozide.