↓ Blood supply and oxygenation to local skin tissue
Ischemia
Degradation of intact skin
Abrasion (damage by scrape/rub)
Puncture (small piercing caused by sharp object)
Acute injury to the skin
Crush (damage by compression)
Acute Wound Healing:
Pathogenesis and clinical findings
Author: Amanda Eslinger Mina Youakim Reviewers: Heena Singh Shahab Marzoughi Yan Yu Laurie Parsons* * MD at time of publication
8 – 365+ days post-injury
Remodeling
(↓ blood vessels & organized collagen)
Extensively cross-linked type 1 collagen replaces the disorganized
collagen laid down in the proliferative phase
↑ Protein content in collagen
Scarring (fibrotic tissue replaces previously healthy tissue)
Disruption of structure and function of dermis, epidermis and subdermal tissues
Subendothelial and endothelial damage activates the coagulation pathway
Formation of a platelet plug
Bleeding is slowed or stopped by
hemostatic plug (hemostasis)
Clot unifies wound edges
0 – 7 days post-injury
Inflammation
(In disrupted skin layers)
4 – 14 days post-injury
Proliferation of collagen, extracellular matrix & blood vessels
TGF-β attracts fibroblasts to the site of the wound
Fibroblast & macrophage stimulate tissue growth &
angiogenesis which replaces hemostatic plug
Scabbing (protective crust overlying damaged tissue)
Re-epithelialization beneath the scab sloughs it off
Healing (newly replaced tissue replaces damaged one)
In response to irritant, mast cells release histamine
Complement activation causing nearby endothelial cells to release prostaglandins
Vasodilation occurs around the wound area
Localized ↑ vascular supply (reception of blood and fluid from vessels)
↑ Hydrostatic pressure forces fluid from vessels into surrounding tissue
Edema (swelling from fluid buildup)
Erythema (redness)
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
First Published Sept 19, 2013; updated Jan 30, 2024 on www.thecalgaryguide.com