Delusional infestation (DI), also known as delusional parasitosis or Ekbom syndrome, is a rare disorder, characterised by fixed belief that the skin, body or immediate environment is infested by small pathogens, despite the lack of any medical evidence for it.

To describe and discuss two clinical cases of DI, in order to show two different ways of presenting in this entity.

Two case report and non-systematic review.

We present the case of a 76-year-old woman, without psychiatric history, with an DI with 5 years of evolution, referred to a psychiatric consultation by a dermatologist. The second case, is a 41-year-old woman with a history of multiple substance use disorder, with an DI with a month of evolution, who resorted to the emergency department. DI is not a single diagnostic entity. The classic form, as represented in the first case,is a primary form, which develops without any known cause or underlying disease, corresponding to a persistent delusional disorder. However, about 60% of patients have secondary forms of DI, in the context of substance misuse, some medications or in the course of physical or psychiatric diseases (e.g. stroke, delirium, dementia, depression, schizophrenia).

DI can occur as a primary delusional disorder or secondary to several other medical conditions. An in-depth clinical history is essential in order to make the correct diagnosis. A multidisciplinary approach is also important, to exclude any possible organic etiology, not forgetting that many patients may turn to other medical specialities first.

No significant relationships.