Epitelisation

Epitelisation, also known as epithelialisation, is the process by which epithelial tissues cover a wound, restoring the skin or mucosal barrier. It involves keratinocytes at the wound margin migrating, proliferating, and differentiating to reconstruct a continuous epithelium. It is a key component of the proliferative phase of wound healing.

Mechanism: After hemostasis and inflammation, basal keratinocytes at the wound edge detach and migrate on a provisional matrix rich in fibrin and extracellular matrix components. Migration is guided by growth factors such as EGF, TGF-α, FGF7 (KGF), and HGF, as well as signals from the surrounding tissue. Proliferation thickens the new epithelium; cells differentiate to reestablish stratification and the basement membrane, leading to formation of the stratum corneum in skin.

Regulation and factors: Moist wound environment, adequate perfusion and oxygen, absence of infection, and proper nutrition promote epithelialisation. Age, diabetes, vascular insufficiency, corticosteroids, and chronic inflammation can delay it. The process must be coordinated with granulation tissue formation and wound contraction, and must be distinguished from scar remodeling; re-epithelialisation refers specifically to epithelial layer restoration.

Clinical relevance and measurement: In clinical practice, epithelialisation is assessed by rate of wound closure and quality of the new epithelium. Delayed epithelialisation is a feature of chronic wounds such as venous ulcers or diabetic ulcers. Therapeutic strategies aim to support moist wound healing, debridement of necrotic tissue, infection control, and, where appropriate, topical growth factors.