Before revision:  The model recapitulates observed  cell density distribution and the epidermal turnover time . We apply the model to study the onset, recurrence and phototherapy-induced remission of psoriasis.
After revision:  The model recapitulates observed cell density distribution and the epidermal turnover time and the multilayered tissue structure. We extend the model to study the onset, recurrence and phototherapy-induced remission of psoriasis.