A 24-year-old man burns his hand after grasping the handle of a hot pan while preparing a meal. Several minutes later, both the initial burn and the area around it are red without blistering. When he presses on the burn, the tissue blanches. Which of the following is most likely contributing to the reaction observed in this patient?

Question

A 24-year-old man burns his hand after grasping the handle of a hot pan while preparing a meal.  Several minutes later, both the initial burn and the area around it are red without blistering.  When he presses on the burn, the tissue blanches.  Which of the following is most likely contributing to the reaction observed in this patient?

Quizplus · Accepted Answer

11ec160b_37c1_781f_9249_cfc123df3286_MD0001_00 This patient has erythema that blanches without blistering, which is characteristic of a superficial burn. Burn wounds are classified according to depth based on which layers of cutaneous and subcutaneous tissues are damaged: The morphologic changes in burns occur due to both direct tissue damage and inflammatory mediators released from epidermal and immune cells. Release of histamine and other preformed vasoactive mediators from mast cells in the minutes following a burn leads to dilation of superficial skin capillaries. This results in blanching erythema (ie, temporary whitening with pressure due to capillary collapse) that extends to the area surrounding the initial burn. Deeper (eg, partial-thickness) burns affect dermal structures such as nerve endings and venules in addition to the epidermis. Nerve damage can lead to loss of sensation while damage to venules can result in fluid extravasation through gaps between injured venule endothelial cells. The result is a blister formed from a collection of serous fluid between the dermis and epidermis (Choice A). (Choices C and E) Platelets and neutrophils play an important role in healing after a thermal burn by releasing prostaglandins, cytokines, and growth factors that stimulate increased blood flow, inflammation, and tissue regrowth. Although both cells contribute to the erythema in and around a burn wound, these changes occur hours to days after the burn rather than minutes after, as in this patient. (Choice D) Platelet-derived growth factor (PDGF) is released by platelets, macrophages, and endothelial cells and plays an important role in generating the vascular and fibroblast proliferation needed for normal wound healing over the days to weeks following the initial injury. Educational objective: The earliest morphologic change that occurs after a superficial thermal burn is erythema due to the release of preformed mediators (eg, histamine) from mast cells. Deeper (eg, partial-thickness) burn wounds form blisters due to fluid extravasation through gaps between damaged venule endothelial cells.

A 24-Year-Old Man Burns His Hand After Grasping the Handle