Ekbom's syndrome
A mistaken belief they are infested with parasites.
Delusional parasitosis (also known as delusions of parasitosis is a form of psychosis whose victims acquire a strong delusional belief that they are infested with parasites, whereas in reality no such parasites are present.
For example, excessive cocaine use can lead to formication, nicknamed “cocaine bugs” or “coke bugs,” where the affected people believe they have, or feel, parasites crawling under their skin. These delusions are also associated with high fevers or extreme alcohol withdrawal, often together with visual hallucinations about insects.
Very often the imaginary parasites are reported as being “bugs” or insects crawling on or under the skin; in these cases the experience of the sensation known as formication may provide the basis for this belief.
Delusional parasitosis is also sometimes referred to as “Ekbom’s syndrome”, named after a Swedish neurologist, Karl Axel Ekbom, who published seminal accounts of the disease in 1937 and 1938. But this can be confusing because others use the term Ekbom’s syndrome interchangeably with Wittmaack-Ekbom syndrome, another name for restless legs syndrome (RLS).
Although delusional parasitosis and RLS were both researched by Ekbom, and RLS sufferers sometimes describe some of their symptoms as if they have, for example, “ants in my veins”, the similarities stop there. RLS is a physical condition with physical causes, whereas delusional parasitosis is a false belief.
The false belief of delusional parasitosis stands in contrast to actual cases of parasitosis, such as scabies.
People with delusional parasitosis are likely to ask for help not from psychiatrists but from dermatologists, veterinarians, pest control specialists, or entomologists. Because delusional parasitosis is not at all well known to non-specialists, under those circumstances the condition often goes undiagnosed, or may be incorrectly diagnosed.