What is the primary chemical mediator involved in the inflammatory response and pain generation following a spilled hot water burn?

Chemical Mediator in Hot Water Burns

The primary chemical mediator in a spilled hot water burn is prostaglandins (option D). Prostaglandins play a crucial role in the inflammatory response and pain generation following thermal injuries such as hot water burns 1.

Pathophysiology of Hot Water Burns

When hot water contacts the skin, it triggers a cascade of inflammatory responses involving several chemical mediators:

1. Initial response: Thermal injury damages cell membranes, releasing arachidonic acid which is metabolized via the cyclooxygenase pathway to produce prostaglandins

2. Inflammatory cascade:

   • Prostaglandins act as vasodilators that potentiate plasma exudation
   • They work in conjunction with permeability-increasing mediators like histamine and bradykinin
   • This interaction leads to the characteristic inflammatory response seen in burns 1

3. Pain generation: Prostaglandins sensitize nociceptors to painful stimuli, making them a key mediator in burn-related pain

Why Prostaglandins Are the Primary Mediator

While multiple chemical mediators are involved in the burn response, prostaglandins are considered primary because:

• They are directly targeted by non-steroidal anti-inflammatory drugs (NSAIDs), which are effective in reducing burn pain and inflammation 1
• They have a sustained role throughout the inflammatory process, unlike some other mediators that act more transiently
• They contribute significantly to both the vascular changes and pain sensitization

Role of Other Options in the Question

• Serotonin (A): While serotonin can be released during tissue injury, it is not the primary mediator in thermal burns

• Bradykinins (B): Bradykinins do play a role as permeability-increasing mediators, but they work in conjunction with prostaglandins rather than being the primary mediator 1

• Thromboxane (C): Thromboxane is another arachidonic acid metabolite that can be involved in the inflammatory response, but prostaglandins have a more dominant role in thermal burns

Clinical Implications

Understanding prostaglandins as the primary mediator explains why:

• NSAIDs are effective in managing burn pain through their inhibition of prostaglandin synthesis
• Multimodal pain management approaches for burns often include NSAIDs alongside other analgesics 2
• Early cooling of burns helps limit prostaglandin production by reducing the inflammatory cascade

This knowledge guides the pain management approach recommended in burn care guidelines, which includes NSAIDs as part of a multimodal strategy alongside acetaminophen and opioids when needed 2.