Skin Desquamation: The 27- to 30-Day Epidermal Renewal Cycle

The epidermis undergoes continuous turnover: keratinocytes proliferate in the basal layer, differentiate as they migrate outward, and are shed as corneocytes from the stratum corneum. This cycle—desquamation—takes approximately 27–30 days in adults. It maintains barrier integrity, facilitates wound healing, and regulates skin hydration.