Editing Pathognomonic

{{Short description|Medical term meaning "characteristic for a particular disease"}}
'''Pathognomonic''' (synonym ''pathognomic''<ref>{{cite web|url=https://en.oxforddictionaries.com/definition/pathognomic |archive-url=https://web.archive.org/web/20180527120714/https://en.oxforddictionaries.com/definition/pathognomic |url-status=dead |archive-date=May 27, 2018 |publisher=Oxford Dictionaries |title=Pathognomic}}</ref>) is a term, often used in [[medicine]], that means "characteristic for a particular [[disease]]". A pathognomonic [[Signs and symptoms|sign]] is a particular sign whose presence means that a particular disease is present beyond any doubt. The absence of a pathognomonic sign does not rule out the disease.  Labelling a sign or [[Signs and symptoms|symptom]] "pathognomonic" represents a marked intensification of a "diagnostic" sign or symptom.

The word is an adjective of [[Ancient Greek|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|positive predictive value]] and high [[sensitivity and specificity|specificity]]<!--not always 100% but always close--> but does not need to have high [[sensitivity and specificity|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|date=December 2021}}

Singular pathognomonic signs are relatively uncommon. Examples of pathognomonic findings include [[Koplik's spots]] inside the [[mouth]] in [[measles]], the palmar [[xanthoma]]ta 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]], or [[succinylacetone]] for [[Tyrosinemia]] Type I.{{citation needed|date=December 2021}}

As opposed to [[symptom]]s (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 anemia]]s (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|date=December 2021}}

In contrast, a test with very high [[sensitivity and specificity|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]].<ref>{{cite journal | vauthors = Lynch HT, Lynch JF, Lynch PM, Attard T | title = Hereditary colorectal cancer syndromes: molecular genetics, genetic counseling, diagnosis and management | journal = Familial Cancer | volume = 7 | issue = 1 | pages = 27–39 | year = 2007 | pmid = 17999161 | doi = 10.1007/s10689-007-9165-5 | s2cid = 20103607 }}</ref><ref>{{cite journal | vauthors = Lynch HT, Lanspa SJ | title = Colorectal cancer survival advantage in MUTYH-associated polyposis and Lynch syndrome families | journal = Journal of the National Cancer Institute | volume = 102 | issue = 22 | pages = 1687–9 | date = November 2010 | pmid =  21044965| doi = 10.1093/jnci/djq439 }}</ref>

==Examples==
{| class="sortable wikitable"
! Disease || Sign
|-
| [[Cytomegalovirus infection]] || [[Owl's eye appearance]] of [[inclusion bodies]]<ref>Page 268 in: {{cite book | last1 = Gibbs | first1 = Ronald Darnley | last2 = Sweet | first2 = Richard L. | name-list-style = vanc |title=Infectious Diseases of the Female Genital Tract |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2009 |isbn=978-0-7817-7815-2 }}</ref><ref>{{cite journal | vauthors = Mattes FM, McLaughlin JE, Emery VC, Clark DA, Griffiths PD | title = Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7 | journal = Journal of Clinical Pathology | volume = 53 | issue = 8 | pages = 612–4 | date = August 2000 | pmid = 11002765 | pmc = 1762915 | doi = 10.1136/jcp.53.8.612 }}</ref>
|-
| [[Lyme disease]] || [[Erythema chronicum migrans]]<ref>{{cite journal | vauthors = Ogden NH, Lindsay LR, Morshed M, Sockett PN, Artsob H | title = The rising challenge of Lyme borreliosis in Canada | journal = Canada Communicable Disease Report | volume = 34 | issue = 1 | pages = 1–19 | date = January 2008 | pmid = 18290267 | url = http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/08vol34/dr-rm3401a-eng.php }}</ref>
|-
| [[Inclusion body myositis]] || Filamentous material seen in inclusion bodies under electron microscopy
|-
| [[Hypocalcemia]]  || [[Trousseau sign of latent tetany|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 pancreatitis|Chronic hemorrhagic pancreatitis]] || [[Grey-Turner's sign]] (ecchymosis in flank area)
|-
| [[Cholera]] || [[Infectious diarrhea|Rice-watery stool]]
|-
| [[Enteric fever]] || [[Rose spots]] in abdomen
|-
| [[Meningitis]] || [[Kernig's sign]] and [[Meningism#Brudzinski's signs|Brudzinski's sign]]
|-
| [[Angina pectoris]] || [[Levine's sign]] (hand clutching of chest)<ref>{{cite book | url=https://books.google.com/books?id=Kse7AgAAQBAJ&q=%22Levine%27s+sign%22+pathognomonic&pg=PA355 | title=Textbook of Physical Diagnosis: History and Examination | publisher=[[Elsevier]] | first = Mark H. | last = Swartz | name-list-style = vanc | year=2014 | pages=354 | isbn=9780323225076}}</ref>
|-
| [[Patent ductus arteriosus]] || Machine-like murmur
|-
| [[Parkinson's disease]]{{citation needed|date=April 2014}} || [[Parkinsonism|Pill-rolling tremors]]{{citation needed|date=April 2014}}
|-
| [[Whipple's disease]] || Oculo-masticatory myorhythmia
|-
| [[Acute myeloid leukemia]] || [[Auer rod]]
|-
| [[Multiple sclerosis]] || Bilateral [[internuclear ophthalmoplegia]]
|-
| [[Pericarditis]] || [[Pericardial friction rub]]
|-
| [[Rheumatic fever]] || [[Aschoff nodules|Aschoff bodies]]
|-
| [[Rabies]] || [[Rabies#Hydrophobia|Hydrophobia]] and [[negri bodies]]
|-
| [[Gout]] || [[Tophi]]
|-
| [[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]]
|-
|[[Parkinson's disease]]
|[[Rigidity (neurology)|Rigidity]] with [[tremor]]<ref>{{Cite book |last=Arslan |first=Orhan E. |title=Neuroanatomical Basis of Clinical Neurology, Second Edition |date=2015 |publisher=CRC Press |isbn=978-1-4398-4834-0 |edition=2nd |location=Hoboken |page=473}}</ref>
|-
|[[Atrial flutter]]
|[[Flutter waves]]<ref>{{cite journal |last1=Bernstein |first1=Neil E. |last2=Sandler |first2=David A. |last3=Goh |first3=Mark |last4=Feigenblum |first4=David Y. |last5=Holmes |first5=Douglas S. |last6=Chinitz |first6=Larry A. |title=Why a Sawtooth? Inferences on the Generation of the Flutter Wave during Typical Atrial Flutter Drawn from Radiofrequency Ablation |journal=Annals of Noninvasive Electrocardiology |date=15 October 2004 |volume=9 |issue=4 |pages=358–361 |doi=10.1111/j.1542-474X.2004.94576.x |pmid=15485514 |pmc=6932011 }}</ref>
|-
|[[Sickle cell disease]]
|[[Vaso-occlusive crisis|Vaso-occlusive crises]]<ref>{{cite journal | vauthors = Rami Helvaci M, Ayyildiz O, Gundogdu M | title = Gender differences in severity of sickle cell diseases in non-smokers | journal = Pakistan Journal of Medical Sciences | volume = 29 | issue = 4 | pages = 1050–4 | date = July 2013 | pmid = 24353686 | pmc = 3817781 }}</ref>
|-
|[[Lightning injury]]
|[[Lichtenberg figure]] on skin<ref>{{cite journal | pmc=8226253 | date=2021 | last1=Lindford | first1=A. | last2=Juteau | first2=S. | last3=Jaks | first3=V. | last4=Klaas | first4=M. | last5=Lagus | first5=H. | last6=Vuola | first6=J. | last7=Kankuri | first7=E. | title=Case Report: Unravelling the Mysterious Lichtenberg Figure Skin Response in a Patient with a High-Voltage Electrical Injury | journal=Frontiers in Medicine | volume=8 | doi=10.3389/fmed.2021.663807 | doi-access=free | pmid=34179045 }}</ref><ref>{{cite journal | url=https://ui.adsabs.harvard.edu/abs/2015JASTP.136..119C/abstract | bibcode=2015JASTP.136..119C | title=On the possible mechanism of keraunographic markings on lightning victims | last1=Cooray | first1=Vernon | last2=Cooray | first2=Gerald K. | last3=Cooray | first3=Charith | journal=Journal of Atmospheric and Solar-Terrestrial Physics | date=2015 | volume=136 | page=119-123 | doi=10.1016/j.jastp.2015.06.006 }}</ref>
|}

== See also ==
* [[AIDS defining clinical condition]]
* [[List of eponymous medical signs]]
* [[Medical sign]]
* [[Sine qua non]]

== References ==
{{reflist}}

== External links ==
{{Wiktionary}}
* [https://www.youtube.com/watch?v=2DqSvQEAp6U Slide show with audio summary of 122 pathognomonic signs]

[[Category:Medical terminology]]
[[Category:Medical signs]]
[[Category:Symptoms]]