Delusional infestation: are you being bugged?

This case report documents a 58-year-old male who presented to the clinic with a 12-month history of a burrowing sensation in his eyelids that he attributed to a parasitic infestation. After being extensively investigated and reviewed by relevant specialties, no evidence of parasitic infestation was found. He was diagnosed with and treated for blepharitis. Psychiatric referral for presumed delusional infestation (DI) was recommended. Despite this, he remained insistent in his belief of infestation, and was inevitably lost to follow-up. DI, previously known as delusional parasitosis, is a rare delusional disorder where affected individuals have a fixed, false belief that they have a parasitic infestation. Diagnosis can be challenging. Practitioners need to evaluate between primary and secondary DI carefully, as management differs depending on the etiology. Despite this, patients diagnosed with primary DI tend to be resistant to psychiatric referral. This report aims to optimize management by giving the reader a guideline for appropriate investigations and advice on patient approach. It is important to recognize hallmark features of DI to minimize self-inflicted trauma and associated psychosocial consequences. Effective treatment for DI is available, and devastating consequences, including blindness, can be avoided.