Pseudoepitheliomatous hyperplasia formation after skin injury.

Pseudoepitheliomatous hyperplasia (PEH) is characteristic of reactive epithelial downward proliferation into the dermis. To explore the mechanism of PEH formation, we investigated the cause, clinical characteristics, histopathologic change, and clinical treatment of PEH, the expression characteristics of stem cell factor (SCF), and its receptor c-Kit in PEH and normal skin of PEH edge (PEH-N). The clinical data of 11 patients with PEH were reviewed, and biopsy examination and bacterial cultures were performed.