Final answer:
Delusory parasitosis involves the belief in having parasites like Loa loa despite a lack of medical evidence, distinguishing it from a fear of insects or hallucinations.
Step-by-step explanation:
A person who is diagnosed with delusory parasitosis has C) A belief in having parasites despite evidence to the contrary. This condition is characterized by an unfounded belief that one is infested with parasites, despite there being no medical evidence to support this. The condition differs from a fear of insects, obsessive-compulsive disorder, or hallucinations related to parasitic infestations. In delusory parasitosis, the person may experience a strong conviction of being infested by parasites similar to the Loa loa helminth, which causes loiasis, even when such an infestation is not present. Unlike cases of actual parasitic diseases like loiasis or elephantiasis caused by roundworm parasites, delusory parasitosis is a mental health condition.