[Xeroderma pigmentosum: development of photoformation of hydrogen peroxide and catalytic activity in skin cells; application to an early diagnosis and to a tentative treatment].

In Xeroderma pigmentosum (XP) a genetic-recessive ultraviolette-hypersensitive disease we found an accumulation of photoproduced H2O2 in skin cells accompanied by a breakdown of the catalatic activity. Both disorders intensified as the disease progressed. Concomitantly with these processes, one electrochemical peak of urine decreases. By the time epitheliomas appeared, this peak was no longer detectable. Several applications to the skin of a cream containing catalase seemed to prevent the formation and the evolution of neoplastic tumors during the treatment.