Chapter 11 – Burns and Scalds (Knight’s Forensic Pathology)

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A complete set of 150 English question-and-answer flashcards covering Chapter 11 (Burns and Scalds) from Knight’s Forensic Pathology, suitable for exam revision.

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128 Terms

1
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What causes the characteristic cherry-pink discoloration seen in many fire victims?

Carboxyhaemoglobin formed from carbon-monoxide inhalation.

2
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Which cerebellar cells are typically damaged in fatal heat-stroke?

Purkinje cells.

3
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Which burn type shows a precise outline that matches the heated object?

Contact burn.

4
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Which autopsy feature indicates antemortem burning?

A red inflammatory line (line of redness) around the burn margin.

5
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In forced-immersion scalds, what typical pattern appears on the buttocks of children?

Doughnut burns (central sparing with peripheral burn).

6
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Which burn-depth category destroys full skin thickness and is usually painless?

Third-degree (full-thickness) burn.

7
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What heat-related posture results from muscular contraction and produces a ‘boxer-like’ stance?

Pugilistic attitude.

8
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A well-demarcated scald without splash marks in a child most strongly suggests what?

Intentional immersion (non-accidental injury).

9
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Which toxic gas is the most frequent cause of death in fire victims?

Carbon monoxide.

10
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Which combustion product can cause almost instantaneous death before burns develop?

Hydrogen cyanide.

11
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What burn distribution is typical of a flash explosion?

Superficial, wide burns that spare areas covered by clothing.

12
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What gross brain change is often noted at autopsy in heat-stroke cases?

Cerebral oedema with flattened gyri.

13
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Which microscopic feature distinguishes antemortem burns?

Early neutrophilic infiltration at the burn edge.

14
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Which blood finding is characteristic in a victim who inhaled fire smoke while alive?

Elevated carboxyhaemoglobin level.

15
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What clinical feature is classical of heat-stroke in elderly patients?

Anhidrosis (absence of sweating).

16
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Which clothing material carries the greatest risk of deep burns because it melts?

Synthetic fabrics.

17
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Define the ‘wick effect’ sometimes mislabelled as spontaneous combustion.

Body fat melts and, like candle wax, sustains a localized flame that slowly consumes tissue.

18
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How can skull heat fractures be differentiated from traumatic fractures?

Heat fractures have irregular, often bevelled edges and lack associated bleeding.

19
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Heat haematomas usually collect in which intracranial location?

The frontal or temporal extradural (epidural) space.

20
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For what purpose is Wallace’s Rule of Nines primarily used?

Rapid estimation of the percentage of total body surface area (TBSA) burned.

21
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What is the primary mechanism of tissue destruction in thermal burns?

Protein denaturation and coagulative necrosis.

22
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Which skin area offers the greatest natural resistance to heat damage?

Palmar (thick) skin of the hands.

23
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Which burn degree is typically associated with painful blisters?

Second-degree (partial-thickness) burn.

24
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Which chart is most accurate for estimating burn surface area in children?

Lund and Browder chart.

25
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A full-thickness burn often appears how on gross inspection?

Leathery and insensate (painless).

26
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Burns associated with ignition of clothing are classified as what type?

Flame burns.

27
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Why are burns over >30 % TBSA particularly dangerous?

They cause burn shock from massive plasma loss.

28
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Loss of the skin barrier in large burns chiefly predisposes to what complication?

Systemic infection/sepsis.

29
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Forced sitting in hot water usually produces which burn pattern?

Doughnut burns on buttocks and perineum.

30
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What liquid is responsible for the majority of scald injuries?

Hot water.

31
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Which key feature characterises immersion scalds on the body?

A sharp upper border with uniform depth below it.

32
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Uniform burns without splash marks are highly suspicious for what?

Non-accidental (intentional) injury or abuse.

33
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Give an example of a classic dry-heat source that causes contact burns.

A hot iron (or any heated metal surface).

34
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Flash burns commonly spare which areas?

Regions protected by clothing or hair.

35
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Burning plastics often liberate which lethal gas?

Hydrogen cyanide.

36
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What immediate physical process produces pugilistic attitude in a body exposed to fire?

Heat-induced coagulation and shortening of muscle proteins and tendons.

37
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Which finding suggests a burn occurred post-mortem?

Clear, air-filled blisters with no inflammatory base.

38
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What single autopsy observation most strongly proves the victim breathed during the fire?

Carbon soot deposition in the trachea and bronchi.

39
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Heat haematomas are most frequently located where?

Frontal extradural (epidural) region of the skull.

40
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What burn-related skin split may mimic an incised wound?

A thermal fissure (heat tear).

41
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What colour change of tissues is typical in carbon-monoxide poisoning?

Bright cherry-pink discolouration.

42
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Which burn type often reproduces the exact outline of the causative object?

Contact burn.

43
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Overall, what is the leading mechanism of death in fires?

Carbon-monoxide poisoning rather than the thermal injury itself.

44
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Which posture produced by heat exposure resembles a boxer guarding himself?

Pugilistic attitude.

45
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What is the dominant macroscopic brain finding in fatal heat-stroke?

Diffuse cerebral oedema (flattened gyri, narrowed sulci).

46
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What renal tubular finding is typical in heat-stroke victims?

Albumin (protein) casts within renal tubules.

47
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How does hydrogen cyanide cause cellular death?

By blocking cytochrome oxidase and producing cellular asphyxiation.

48
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State the hallmark triad of malignant hyperthermia.

Rapid hyperthermia, generalized muscle rigidity, and metabolic acidosis/raised CK.

49
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What major clinical difference separates classical from exertional heat-stroke?

Classical heat-stroke features absence of sweating; exertional may still have sweating.

50
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Which heat-related artifact can resemble an extradural haemorrhage on CT or autopsy?

Heat haematoma.

51
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In the wick effect, what bodily substance actually fuels the fire?

Liquefied body fat acting as combustible fuel.

52
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Describe the appearance of post-mortem burned skin.

Dry, parchment-like, yellow-brown surface with no vital reaction.

53
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Approximately what blood carboxyhaemoglobin level is usually fatal?

About 50 % saturation or higher.

54
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Which white blood cell predominates in early vital reaction to a burn?

Neutrophils.

55
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Why are synthetic fabrics hazardous during flame exposure?

They melt and adhere to skin, causing deeper contact burns.

56
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What common hepatic lesion is encountered in severe heat-stroke?

Centrilobular (zone 3) hepatic necrosis.

57
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Identify a moist-heat burn type.

Scald burn from hot liquid or steam.

58
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What pulmonary change is frequently observed after intense heat inhalation?

Frothy, often blood-tinged fluid in airways (pulmonary oedema).

59
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Which CNS neuronal population is first to show necrosis in hyperthermia?

Cerebellar Purkinje cells.

60
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Benign environmental hyperthermia is chiefly caused by what?

Exogenous heat exposure without underlying pathology.

61
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List four major systemic complications that follow extensive burns.

Hypovolaemic shock, electrolyte imbalance, acute renal failure, and sepsis/MODS.

62
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Contrast heat-contact burns with immersion scalds in forensic terms.

Contact burns are localised with object imprint; immersion scalds are symmetrical with sharp waterline, suggesting possible abuse.

63
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Why does airway soot deposition conclusively indicate vitality during fire exposure?

Soot can reach the tracheobronchial tree only if the victim was actively breathing.

64
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Give three histological differences between antemortem and post-mortem burns.

Antemortem burns show vascular congestion, oedema, and neutrophil influx; post-mortem burns lack inflammation and vital reaction.

65
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Define heat tears and state their forensic importance.

Post-mortem splits in charred skin from dehydration; may mimic sharp trauma and must be distinguished histologically.

66
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Enumerate the forensic implications of the pugilistic attitude.

Indicates heat exposure, rules out defensive posture, aids reconstruction of body position during burning.

67
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How can one separate traumatic extradural haemorrhage from a heat haematoma?

Traumatic bleeds are clotted, often unilateral, and linked to skull fracture; heat haematomas are gelatinous, bilateral, and fracture-free.

68
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Name three toxic agents in smoke and specify their effects.

CO (hypoxia), HCN (cellular asphyxia), aldehydes/irritants (airway oedema and chemical injury).

69
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Summarise the Rule of Nines for burn assessment.

Head 9 %, each arm 9 %, each leg 18 %, anterior trunk 18 %, posterior trunk 18 %, perineum 1 % — for rapid TBSA calculation.

70
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How do synthetic fibres alter burn pattern interpretation?

They melt, adhere, and may imprint fabric weave, helping confirm clothing worn at ignition.

71
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List three burn-pattern clues that differentiate accidental scalds from abuse.

Irregular splash marks imply accident; sharp upper demarcation and doughnut pattern suggest forced immersion (abuse).

72
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Explain the forensic significance of delayed medical management in burns.

Lack of treatment may indicate neglect, increases infection, and provides timeline clues through varied healing stages.

73
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Differentiate thermal fissures from knife wounds.

Thermal fissures are irregular, dry, bloodless splits; knife wounds have sharp, regular edges and vital bleeding.

74
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How do flash burns differ from flame burns regarding depth and distribution?

Flash burns are superficial and widespread, sparing clothed skin; flame burns are deeper and often localised to ignition points on clothing.

75
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Describe the fatal pathophysiological cascade of heat-stroke.

Loss of thermoregulation → hyperthermia → vasodilation & hypotension → enzymatic failure → multi-organ dysfunction and death.

76
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List three gross pulmonary findings in heat-stroke and state their significance.

Pulmonary oedema, congestion, and frothy airway fluid indicate respiratory compromise contributing to death.

77
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Contrast skull heat fractures with blunt-force fractures.

Heat fractures are irregular, non-radiating, and bloodless; blunt-force fractures radiate from impact and show haemorrhage.

78
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Name four external post-mortem features commonly seen in burned bodies.

Charred/leathery skin, bullae, singed hair, pugilistic attitude.

79
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Outline brain changes found at autopsy in heat-stroke.

Diffuse oedema, flattened gyri, petechial haemorrhages, and selective neuronal death (Purkinje/cortical).

80
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List four methods used to identify severely burned bodies.

Dental records, DNA profiling, medical implants/serial numbers, and personal effects correlation.

81
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Why are elevated CK and aldolase informative in heat deaths?

They indicate rhabdomyolysis from muscle breakdown, common in exertional and malignant hyperthermia.

82
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Define malignant hyperthermia and its anaesthetic triggers.

An inherited skeletal-muscle disorder triggered by agents such as halothane or succinylcholine, causing fulminant hyperthermia and rigidity.

83
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How does soot distribution assist in estimating survival time during a fire?

Soot deep in bronchi/alveoli suggests several breaths; superficial only suggests brief survival; absence indicates post-mortem burning.

84
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State two crucial scene observations that refute claims of spontaneous combustion.

Presence of an ignition source (e.g., cigarette/heater) and limited fire damage beyond the body (supports wick effect).

85
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What forensic value does cherry-pink skin carry in burned bodies?

Signals high carboxyhaemoglobin, proving the victim inhaled CO while alive.

86
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Give two ways post-mortem skin changes can mimic trauma in burn victims.

Heat fissures look like cuts and bullae can resemble blunt contusions, potentially misleading investigation.

87
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Explain the forensic relevance of rhabdomyolysis in hyperthermic deaths.

Muscle breakdown releases myoglobin, causing renal failure and confirming exertional or malignant hyperthermia as cause.

88
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How can flame-burn patterns help reconstruct body position during the fire?

Areas shielded by clothing or pressed to the floor remain less burned, indicating orientation and possible restraint.

89
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List four clues suggesting a burn victim was unconscious before the fire began.

Uniform burns, absence of defended areas, no airway soot, and minimal vital inflammatory reaction at burn edges.

90
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Enumerate the classic clinical signs of classical (non-exertional) heat-stroke.

Core temperature >40.5 °C, anhidrosis, altered mental status/coma, hot dry skin, tachypnoea/tachycardia.

91
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Summarise systemic physiological responses to extensive burns.

Capillary leak and hypovolaemia, electrolyte shifts, renal failure risk, immunosuppression, and systemic inflammatory response syndrome.

92
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List four principal thermal burn types with distinguishing features.

Flame (deep), contact (object outline), flash (superficial wide), scald (moist, gravity run-off).

93
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Describe four autopsy criteria used to confirm immersion scald abuse.

Symmetric gloves/socks pattern, sharp waterline, doughnut buttock burns, absence of splash marks/inconsistent history.

94
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Contrast antemortem versus post-mortem burn features at autopsy.

Antemortem burns show redness, blisters with proteinaceous fluid, neutrophils, soot in airway; post-mortem burns are dry, bloodless, with no inflammatory cells.

95
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Discuss the role of airway soot in confirming vitality during fires.

Its presence proves respiration during fire; absence favours post-mortem burning or rapid incapacitation before flames.

96
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Detail gross and microscopic characteristics of heat haematomas.

Soft, gelatinous dark collections in extradural space without skull fracture; microscopically show thermal coagulation rather than arterial rupture.

97
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Explain why pugilistic attitude is not evidence of a struggle.

It results from heat-induced muscle contraction post-mortem, not from voluntary defensive action.

98
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State five utilities of the Rule of Nines in forensic practice.

TBSA estimation, prognosis, evaluating survivability, fluid resuscitation guidance, and assessing feasibility of self-rescue.

99
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List common toxicological findings in fire deaths and their interpretations.

COHb >50 % (CO poisoning), blood cyanide (HCN inhalation), irritant aldehydes (airway injury), helping determine cause of death.

100
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Define the wick effect and list two key scene clues that support it.

Body fat sustains a candle-like flame; clues include minimal surrounding fire damage and presence of ignition source such as a dropped cigarette.