A diagnosis of exclusion or by exclusion (''per exclusionem'') is a
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine "cause and effect". In systems engin ...
of a medical condition reached by a
process of elimination, which may be necessary if presence cannot be established with complete confidence from history, examination or testing. Such elimination of other reasonable possibilities is a major component in performing a
differential diagnosis
In healthcare, a differential diagnosis (abbreviated DDx) is a method of analysis of a patient's history and physical examination to arrive at the correct diagnosis. It involves distinguishing a particular disease or condition from others that p ...
.
Diagnosis by exclusion tends to occur where scientific knowledge is scarce, specifically where the means to verify a diagnosis by an objective method is absent. As a specific diagnosis cannot be confirmed, a fall back position is to exclude that group of known causes that may cause a similar clinical presentation.
The largest category of diagnosis by exclusion is seen among psychiatric disorders where the presence of physical or organic disease must be excluded as a prerequisite for making a functional diagnosis.
Examples
An example of such a diagnosis is "
fever of unknown origin
Fever of unknown origin (FUO) refers to a condition in which the patient has an elevated temperature (fever) but, despite investigations by a physician, no explanation has been found. ": to explain the cause of elevated temperature the most common causes of unexplained fever (infection,
neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
, or collagen vascular disease) must be ruled out.
Other examples include:
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Adult-onset Still's disease
Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of fevers, joint pain, and a distinctive salmon-colored bumpy rash. The disease is considered a diag ...
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Behçet's disease
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Bell's palsy
Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary ...
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Burning mouth syndrome
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Chronic recurrent multifocal osteomyelitis
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Long COVID
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Psychogenic polydipsia
Primary polydipsia and psychogenic polydipsia are forms of polydipsia characterised by excessive fluid intake in the absence of physiological stimuli to drink. Psychogenic polydipsia which is caused by psychiatric disorders, often schizophrenia, i ...
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Schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social w ...
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Somatic symptom disorder
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Sudden infant death syndrome
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Tolosa–Hunt syndrome
See also
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Idiopathic
References
{{DEFAULTSORT:Diagnosis Of Exclusion
Medical terminology