Cell proliferation in psoriatics

In psoriasis the DNA synthesis time (ts) of keratinocytes in characteristically lengthened in unaffected skin, and in very early and also fully developed lesions. The prolongation of ts in unaffected psoriatic skin can be increased significantly by removal of the horny layer with adhesive tape. After the same procedure, ts remains unchanged in healthy skin and becomes shortened in the skin of patients suffering from atopic dermatitis. These variations of ts after a standardized irritation indicate that this phenomenon may be used in diagnosis of latent psoriasis.