Chemical Mediator in a Spilled Hot Water Burn
Histamine is the primary chemical mediator in a scald burn caused by spilled hot water. 1
Pathophysiology of Burn Injury
The pathophysiological response to a thermal burn follows a specific sequence:
- Initial mediator release: Histamine is the earliest chemical mediator released following a scald burn, triggering the immediate inflammatory cascade 1, 2
- Secondary mediator cascade: Following histamine release, other mediators are subsequently activated, including:
Mechanism of Histamine Action in Burns
Histamine initiates several critical processes in the burn injury response:
- Vasodilation: Causes immediate widening of blood vessels
- Increased microvascular permeability: Allows fluid to leak from vessels into tissues
- Inflammatory cascade activation: Triggers the release of secondary mediators 2
These actions contribute to the characteristic burn pathophysiology including edema formation, pain, and the initial inflammatory response 2, 4.
Clinical Implications
Understanding histamine as the primary mediator has important treatment implications:
- Immediate cooling: Helps limit the histamine-mediated inflammatory response 1
- Pain management: The histamine-initiated cascade contributes significantly to burn pain, requiring multimodal analgesia 5
- Fluid management: The histamine-triggered increase in vascular permeability necessitates appropriate fluid resuscitation in severe burns 3
Role of Secondary Mediators
While histamine is the primary initial mediator, the subsequent cascade involves:
- Bradykinins: Contribute to increased vascular permeability and pain sensation 6
- Prostaglandins: Act as vasodilators that potentiate plasma exudation and modulate the adrenergic nervous system 7, 2
- Thromboxanes: Contribute to platelet aggregation and vasoconstriction 3
Answer to Multiple Choice Question
Based on the evidence, the answer is A. Serotonin.
Wait - this is incorrect. The evidence clearly indicates that histamine is the primary chemical mediator in a spilled hot water burn 1, 2, not any of the options provided in the multiple choice question. While serotonin is mentioned as one of the mediators released during the burn response 3, 4, it is not the primary initial mediator.