Long-term and short-term histopathologic changes in the skin after PU VA therapy

ABSTRACT

Psoriatic patients engaged in chronic psoralen and long-wave ultraviolet light therapy (PUVA) were evaluated for temporary and permanent histologic changes of the skin. Biopsies of skin from the buttock were taken before, during, and three years after PUVA therapy and histologic changes were compared. Hyperkeratosis, acanthosis, melanosis, and occasional focal dysplasia were noted in the epidermis. Increased deposition of acid mucopolysaccharide (hyaluronic acid), decreased, fragmented elastic fibers within the papillary dermis, and increased, thickened elastic fibers within the reticular dermis were observed. Comparison between changes seen after long-term continuous PUVA therapy and those seen three years later showed no significant differences, indicating that these changes may be irreversible.