Delusional infestation (DI) is a psychodermatologic disorder characterized
by the presence of a fixed, false belief that one is infested with living or non-living
organisms. Patients with DI also endorse associated abnormal cutaneous symptoms
such as crawling, biting or itching. DI can be extremely debilitating, as patients seek
treatment and resort to self-injurious behaviors to eliminate fictional pathogens. Thus,
patients may present with skin changes secondary to skin picking and excoriations.
Patients with DI most often seek the help of dermatologists, because they are unable to
appreciate a psychiatric etiology for their disorder; dermatologists are key to
establishing both treatment and psychiatric referral for these challenging encounters.
Having an informed and optimized approach in handling DI patients is vital, as clinical
interactions with these patients could otherwise be unproductive and unpleasant. With
good therapeutic rapport and a strong doctor-patient relationship, dermatologists may
implement effective treatment with newer, second-generation anti-psychotic
medications or pimozide. In this chapter, the clinical presentation, diagnostic and
interpersonal approach, as well as the treatment of DI, are reviewed.
Keywords: Anti-psychotics, Delusion, Delusional infestation, Delusional
parasitosis, Infestation, Parasitosis, Pimozide.