Delusional infestation: are you being bugged?

Area of Science:

• Psychiatry
• Dermatology
• Ophthalmology

Background:

• Delusional infestation (DI), formerly known as delusional parasitosis, is a rare psychiatric disorder characterized by a fixed, false belief of infestation.
• Accurate diagnosis is challenging, requiring differentiation between primary and secondary DI, as management strategies vary based on etiology.

Observation:

• A 58-year-old male presented with a year-long history of a burrowing sensation in his eyelids, believing it was due to parasitic infestation.
• Extensive investigations by multiple specialties failed to identify any parasitic cause, leading to a diagnosis of blepharitis.

Findings:

• Psychiatric referral for presumed DI was recommended, but the patient remained convinced of infestation and was lost to follow-up.
• Patients with primary DI often resist psychiatric referrals, complicating management and adherence to treatment.

Implications:

• This case underscores the importance of recognizing DI's hallmark features to prevent patient self-inflicted trauma and psychosocial distress.
• Prompt and appropriate management, including recognizing the condition and guiding patient approach, can avert severe outcomes like blindness.