Phases of Wound Healing in Abrasions
Abrasion wound healing progresses through four distinct and partially overlapping phases: hemostasis, inflammatory, proliferative (granulation), and maturation (remodeling). 1
The Four Sequential Phases
1. Hemostasis Phase (Immediate - Minutes to Hours)
Following the abrasion injury, blood clot formation occurs immediately. Degranulating platelets release platelet-derived growth factor (PDGF), which stimulates chemotaxis of neutrophils, monocytes, macrophages, and fibroblasts to initiate the healing cascade. Platelets simultaneously release transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) to promote cell migration and increase vascular permeability. 1
2. Inflammatory Phase (Hours to Days)
Macrophages become the dominant cells, performing wound debridement and secreting multiple growth factors including PDGF, TGF-β, epidermal growth factor (EGF), fibroblast growth factor-2 (FGF-2), and VEGF. These mediators orchestrate the transition to the next phase by recruiting and activating fibroblasts and other repair cells. 1
3. Proliferative/Granulation Phase (Days to Weeks)
This phase involves extensive cellular activity:
- Fibroblast proliferation stimulated by PDGF, FGF-2, and TGF-β drives extracellular matrix synthesis
- Epithelial cell proliferation promoted by EGF, FGF-2, keratinocyte growth factor (KGF), PDGF, TGF-β, and VEGF leads to re-epithelialization
- Angiogenesis occurs through VEGF-mediated endothelial cell proliferation
- Wound contraction begins as fibroblasts differentiate into myofibroblasts under the influence of PDGF and TGF-β 1
4. Maturation/Remodeling Phase (Weeks to Months)
The final phase involves:
- Matrix synthesis and reorganization
- TGF-β orchestrates apoptosis of endothelial cells and fibroblasts to reduce cellularity
- VEGF provides antiapoptotic effects on remaining cells
- Collagen remodeling strengthens the healed tissue 1
Clinical Implications for Abrasion Management
For simple abrasions, pressure patching does NOT improve healing speed or comfort and should be avoided. 2, 3 Instead:
- Clean the wound regularly with water or saline 4
- Apply topical antibiotic ointment to prevent secondary bacterial infection, considering normal skin flora and patient immune status 2, 5
- Maintain a moist wound environment with sterile, inert protective dressing 4
- Consider a bandage contact lens or amniotic membrane for delayed healing cases 2, 5
Common Pitfalls to Avoid
Do not use pressure patching - this outdated practice has been definitively shown to provide no benefit for abrasion healing 2, 5
Ensure adequate eyelid closure (for ocular abrasions) or wound protection - incomplete coverage impairs healing and may require temporary measures like tarsorrhaphy 2, 5
Monitor for infection signs - increased pain, erythema, warmth, or purulent discharge warrant immediate evaluation and possible culture-directed antibiotic therapy 3
The entire healing process typically completes within weeks for superficial abrasions, though the maturation phase continues for months as tissue strength increases through collagen remodeling.