<prompt> Normal turnover rate of epidermis:2 weeks4 weeks6 weeks8 weeks  <response>: Epidermal turnover time - skin doubling time -Time taken by keratinocytes to move from Stratum Basale to environment. -Around 14 days are required to move from Stratum Basale to reach lowermost layer of Stratum Corneum 14 days to cross Stratum Corneum. -Sloughing off requires 28 days So total ETT 56 days 8 weeks The turnover time in psoriasis 4 days. 