Lack of dermal changes in uninvolved skin after photochemotherapy of psoriasis: biochemical studies.

Low Hyp and Hyl values were found in psoriatic lesions. Treatment with PUVA achieved a return to normal values. No effect of PUVA on the collagen of uninvolved skin of psoriatic patients could be demonstrated after 4 months. There were no age-related differences in the content of Hyp and Hyl between samples of uninvolved skin of psoriatics.