Eponymous Triads

Medical triads, tetrads, and pentads are shorthand diagnostic groupings which combine sets of three, four, or five characteristic clinical features. These clusters of signs, symptoms, or pathological findings serve as memorable patterns that help recognise, recall, and communicate specific conditions.

In medicine, a triad is a set of three clinical features that, when found together, strongly suggest a diagnosis; tetrad and pentad extend the idea to four and five linked features. These are teaching tools and memory aids rather than proofs. They can useful in pattern recognition, but are also historically slippery with credit rarely applied to the true originator, and many variants abound.

Etymology: triad from Greek triás (τριάς, “group of three”), tetrad from tetrás (τετράς), pentad from pentás (πεντάς).

PENTADS

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TETRADS

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TRIADS

Amyand’s triad

• Amyand’s hernia
• Appendicitis
• Undescended testis

Coined by Dhanasekarapandian et al in 2018 who published the case of a 35-day-old infant with an irreducible right inguinal hernia, inflamed appendix, and gangrenous undescended testis managed by appendicectomy, orchidectomy, and herniotomy.

• Claudius Amyand (c.1680-1740) was an French-born English surgeon
• Dhanasekarapandian V, Shanmugam V, Jagannathan M. Amyand’s Hernia, Appendicitis, and Undescended Testis: The Amyand’s Triad. J Indian Assoc Pediatr Surg. 2018 Jul-Sep;23(3):169-170.

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Charcot’s Triad

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Dieulafoy’s Triad (Appendicitis) [Triade de Dieulafoy]

Triad of physical findings indicating acute appendicitis outlined by Dieulafoy to differentiate appendicitis from intestinal lithiasis and other causes of abdominal pain.

• Tenderness at McBurney’s point (douleur au point de Mac-Burney)
• Cutaneous hyperaesthesia (hyperesthésie cutanée)
• Involuntary muscular guarding (défense musculaire)

• Georges-Paul Dieulafoy (1839-1911) was a French Clinician
• Dieulafoy G. Lithiase intestinale et entéro-colite. Clinique médicale de l’Hôtel-Dieu de Paris, 1898: I: 296 [trois signes caractéristiques de l’appendicite]

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Dieulafoy’s Triad (functional blindness)

Triad suggestive of functional/hysterical blindness described by Dieulafoy in his clinical lectures at Hôtel-Dieu de Paris.

• Sudden onset of blindness (cécité à début brusque)
• Preserved pupillary light reflexes (conservation des réflexes pupillaires)
• Normal fundoscopic exam (intégrité du fond de l’œil)

Confirmed and cited by Crouzon (1915) in wartime neuropsychiatric observations of sudden blindness without organic findings. Multiple cases published e.g. cécité temporaire provoquée par l’éclatement d’obus à proximité

• Georges-Paul Dieulafoy (1839-1911) was a French Clinician
• Dieulafoy G. Deux case de cécité hystérique. Clinique Médicale de l’Hôtel-Dieu de Paris, 1904; V: 75 [triade symptomatique de la cécité hystérique]

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Merseburger Triad

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Moschcowitz triad (pericardial effusion)

In 1933 Moschcowitz published A new sign of pericardial effusion, in which he described three physical examination findings that, when present together, are indicative of pericardial effusion:

• Widening of the area of cardiac dullness.
• Abrupt transition from pulmonary resonance to cardiac dullness.
• Extension of cardiac dullness into the second intercostal space

I have found that the conjunction of three signs is usually conclusive in determining the diagnosis of pericardial effusion; in the order of their importance, they are: (1) widening of the area of cardiac flatness, (2) abrupt transition from pulmonary resonance to cardiac flatness and (3) widening of the cardiac dullness in the second intercostal space. No one of these signs, taken singly, is conclusive, but together they form a triad which is thoroughly reliable, as confirmed by roentgen examination or at autopsy.

Moschcowitz 1933

Moschcowitz emphasized that while each sign individually might not be conclusive, their combination provides a reliable diagnostic indicator for pericardial effusion, as confirmed by roentgen examination or autopsy

• Eli Moschcowitz (1879-1964) was a Hungarian born, American pathologist and physician
• Moschcowitz E. A new sign of pericardial effusion. JAMA. 1933; 100(21):1663-1664

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Quincke’s triad (hemobilia)

• Right hypochondrium pain
• Jaundice
• Gastrointestinal bleeding (haematemesis and melena)

In 1871, Heinrich Quincke published a detailed case of hepatic artery aneurysm rupture leading to bleeding into the biliary tree. He associated three cardinal features now recognised as Quincke’s triad:

1975 – Eddy Davis Palmer, (1917-2010) first documented use of the term Quincke’s triad of hemobilia in the second edition of his textbook Practical Points in Gastroenterology as:

Quincke’s triad of hemobilia consists of GI hemorrhage, biliary colic, and jaundice.

• Heinrich Irenaeus Quincke (1842-1922) was a German physician
• Quincke H. Ein fall von Aneurysma der Leberarterie. Berliner Klinische Wochenschrift 1871; 8: 349-352 [Hepatic artery aneurysm. Described triad of biliary tract haemorrhage]

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Reidel’s Triad

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Saint’s Triad

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Virchow’s Triad

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Whipple’s triad

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