Medicine:Pathognomonic
Pathognomonic (rare synonym pathognomic[1]) is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any doubt. Labelling a sign or symptom "pathognomonic" represents a marked intensification of a "diagnostic" sign or symptom.
The word is an adjective of Greek origin derived from πάθος pathos "disease" and γνώμων gnomon "indicator" (from γιγνώσκω gignosko "I know, I recognize").
Practical use
While some findings may be classic, typical or highly suggestive in a certain condition, they may not occur uniquely in this condition and therefore may not directly imply a specific diagnosis. A pathognomonic sign or symptom has very high positive predictive value and high specificity but does not need to have high sensitivity: for example it can sometimes be absent in a certain disease, since the term only implies that, when it is present, the doctor instantly knows the patient's illness. The presence of a pathognomonic finding allows immediate diagnosis, since there are no other conditions in the differential diagnosis.[citation needed]
Singular pathognomonic signs are relatively uncommon. Examples of pathognomonic findings include Koplik's spots inside the mouth in measles, the palmar xanthomata seen on the hands of people suffering from hyperlipoproteinemia, Negri bodies within brain tissue infected with rabies, or a tetrad of rash, arthralgia, abdominal pain and kidney disease in a child with Henoch–Schönlein purpura.[citation needed]
As opposed to symptoms (reported subjectively by the patient and not measured) and signs (observed by the physician at the bedside on physical exam, without need for a report) a larger number of medical test results are pathognomonic. An example is the hypersegmented neutrophil, which is seen only in megaloblastic anemias (not a single disease, but a set of closely related disease states). More often a test result is "pathognomonic" only because there has been a consensus to define the disease state in terms of the test result (such as diabetes mellitus being defined in terms of chronic fasting blood glucose levels).[citation needed]
In contrast, a test with very high sensitivity rarely misses a condition, so a negative result should be reassuring (the disease tested for is absent). A sign or symptom with very high sensitivity is often termed sine qua non. An example of such test is a genetic test to find an underlying mutation in certain types of hereditary colon cancer.[2][3]
Examples
| Disease | Sign |
|---|---|
| Cytomegalovirus infection | Owl's eye appearance of inclusion bodies[4][5] |
| Hodgkin's lymphoma |
Reed-Sternberg cells (giant mono- and multinucleated cells) upon microscopy |
| Lyme disease | Erythema chronicum migrans[6] |
| Inclusion body myositis | Filamentous material seen in inclusion bodies under electron microscopy |
| Hypocalcemia | Trousseau sign and Chvostek sign |
| Tetanus or Strychnine poisoning | Risus sardonicus |
| Measles | Koplik's spots |
| Wilson's disease | Kayser–Fleischer ring |
| Diphtheria | Pseudomembrane on tonsils, pharynx and nasal cavity |
| Chronic hemorrhagic pancreatitis | Grey-Turner's sign (ecchymosis in flank area) |
| Cholera | Rice-watery stool |
| Enteric fever | Rose spots in abdomen |
| Meningitis | Kernig's sign and Brudzinski's sign |
| Angina pectoris | Levine's sign (hand clutching of chest)[7] |
| Patent ductus arteriosus | Machine-like murmur |
| Parkinson's disease[citation needed] | Pill-rolling tremors[citation needed] |
| Whipple's disease | Oculo-masticatory myorhythmia |
| Acute myeloid leukemia | Auer rod |
| Multiple sclerosis | Bilateral internuclear ophthalmoplegia |
| Pericarditis | Pericardial friction rub |
| Rheumatic fever | Aschoff bodies |
| Rabies | Hydrophobia and negri bodies |
| Gout | Tophi |
| MASC | ETV6-NTRK3 |
| Acute tubular necrosis | Muddy brown casts |
| Granulosa cell tumour | Call-Exner bodies |
| Malakoplakia | Michaelis–Gutmann bodies |
| Narcolepsy (with cataplexy) | Cataplexy |
| Endodermal sinus tumor | Schiller–Duval body |
| Atrial flutter | Flutter waves[8] |
| Sickle cell disease | Vaso-occlusive crises[9] |
See also
- AIDS defining clinical condition
- List of eponymous medical signs
- Medical sign
- Sine qua non
References
- ↑ "Pathognomic". Oxford Dictionaries. https://en.oxforddictionaries.com/definition/pathognomic.
- ↑ "Hereditary colorectal cancer syndromes: molecular genetics, genetic counseling, diagnosis and management". Familial Cancer 7 (1): 27–39. 2007. doi:10.1007/s10689-007-9165-5. PMID 17999161.
- ↑ "Colorectal cancer survival advantage in MUTYH-associated polyposis and Lynch syndrome families". Journal of the National Cancer Institute 102 (22): 1687–9. November 2010. doi:10.1093/jnci/djq439. PMID 21044965.
- ↑ Page 268 in: Gibbs, Ronald Darnley; Sweet, Richard L. (2009). Infectious Diseases of the Female Genital Tract. Hagerstwon, MD: Lippincott Williams & Wilkins. ISBN 978-0-7817-7815-2.
- ↑ "Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7". Journal of Clinical Pathology 53 (8): 612–4. August 2000. doi:10.1136/jcp.53.8.612. PMID 11002765.
- ↑ "The rising challenge of Lyme borreliosis in Canada". Canada Communicable Disease Report 34 (1): 1–19. January 2008. PMID 18290267. http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/08vol34/dr-rm3401a-eng.php.
- ↑ Swartz, Mark H. (2014). Textbook of Physical Diagnosis: History and Examination. Elsevier. pp. 354. ISBN 9780323225076. https://books.google.com/books?id=Kse7AgAAQBAJ&q=%22Levine%27s+sign%22+pathognomonic&pg=PA355.
- ↑ Bernstein, Neil E.; Sandler, David A.; Goh, Mark; Feigenblum, David Y.; Holmes, Douglas S.; Chinitz, Larry A. (15 October 2004). "Why a Sawtooth? Inferences on the Generation of the Flutter Wave during Typical Atrial Flutter Drawn from Radiofrequency Ablation". Annals of Noninvasive Electrocardiology 9 (4): 358–361. doi:10.1111/j.1542-474X.2004.94576.x. PMID 15485514.
- ↑ "Gender differences in severity of sickle cell diseases in non-smokers". Pakistan Journal of Medical Sciences 29 (4): 1050–4. July 2013. PMID 24353686.
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