RESUMO
This study was suggested to evaluate the possible role of porphyrins and DNA, and their interaction, in some photosensitive premalignant and malignant dermatoses. Twenty-five patients with photosensitive skin diseases viz. xeroderma pigmentosum and basal cell carcinoma, were randomly selected at the outpatient clinic of Dermatology in Mansoura University Hospital. Twenty-five matched normal individuals were used as a control group. In basal cell carcinoma patients, a high increase in skin DNA and decrease in skin total porphyrin, haemoglobin and haem concentrations were observed. In xeroderma pigmentosum, a significant decrease in both skin DNA and skin total porphyrin were found, at the same time, there were elevations in urinary total porphyrin, PBG and ALA concentrations, and a high decrease in haemoglobin and haem levels.