Asphyxial deaths: petechiae in hanging: practice question

A Forensic Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Forensic Medicine · Asphyxial deaths: petechiae in hanging

Sample item

At autopsy of a man found hanging with his full body weight suspended, the face is pale and petechial haemorrhages are absent from the conjunctivae and face. Which explanation is most appropriate?

AThe hanging was carried out after deathBPetechiae never occur in any form of asphyxiaCPetechiae appear only when death follows poisoningDArterial inflow to the head was also obstructed, so venous congestion did not develop

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Arterial inflow to the head was also obstructed, so venous congestion did not develop

Petechiae result from raised venous pressure with continued arterial inflow. In complete suspension the carotid arteries (and often the vertebral arteries) are occluded along with the veins, so little blood enters the head and the face stays pale without petechiae. Petechiae are commoner when venous but not arterial flow is blocked, as in partial hanging and strangulation.

Option by option

A. The hanging was carried out after death
Post-mortem hanging is not shown by the absence of petechiae; vital reaction at the ligature mark is the guide.
B. Petechiae never occur in any form of asphyxia
Petechiae are common in strangulation and partial hanging, so the statement is false.
C. Petechiae appear only when death follows poisoning
Petechiae are not tied to poisoning and have no such rule.
D. Arterial inflow to the head was also obstructed, so venous congestion did not develop (correct)
Correct. Arterial occlusion prevents the pressure build-up needed for petechiae.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is D, Arterial inflow to the head was also obstructed, so venous congestion did not develop. Petechiae result from raised venous pressure with continued arterial inflow.

Why is "The hanging was carried out after death" not the answer?

Post-mortem hanging is not shown by the absence of petechiae; vital reaction at the ligature mark is the guide.

Why is "Petechiae never occur in any form of asphyxia" not the answer?

Petechiae are common in strangulation and partial hanging, so the statement is false.

Why is "Petechiae appear only when death follows poisoning" not the answer?

Petechiae are not tied to poisoning and have no such rule.

What concept does this question test?

It tests Asphyxial deaths: petechiae in hanging in Forensic Medicine. In complete suspension the carotid arteries (and often the vertebral arteries) are occluded along with the veins, so little blood enters the head and the face stays pale without petechiae. Petechiae are commoner when venous but not arterial flow is blocked, as in partial hanging and strangulation.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Asphyxial deaths: petechiae in hanging?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.