ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changing regular of specific cytokeratin (CK) markers expressing in human pseudoepitheliomatous hyperplasia (PEH), keloids (Ke) and hypertrophic scar (HS) lesion, and to explore the correlation between such changes and the different outcomes of wound repair.</p><p><b>METHODS</b>Histopathology and immunohistochemistry (IHC) double staining methods were used in samples of human PEH, Ke, HS and NS to determine the distribution characteristics and changing regularity of CKs in epidermal tissues.</p><p><b>RESULTS</b>No CK8&18 and CK17 expressed in epidermis of NS group, while CK8&18(+) cells and CK17(+) cells were detected in epidermis of active-stage Ke, HS and PEH. The quantities of CK8&18(+) cells and CK17(+) cells ranked as follows: PEH > Ke > HS and HS > Ke > PEH (P < 0.05). CK19(+) cells and CK5&6(+) cells expressed similar changing trend, while reverse trend of CK10(+) cells was detected in epidermal cells, with local epidermal hyperplasia, cells morphological changes and sub-epidermal inflammatory reaction.</p><p><b>CONCLUSION</b>Different degree of de-differentiation and terminal differentiation imbalance are found in epidermal cells of active-stage PEH, Ke and HS, which hint the correlation between the abnormal proliferation and differentiation of epidermal cells and the different outcomes of wound repair.</p>