The purpose of the study was to determine the effect of ultraviolet radiation on the risk of seborrheic keratosіs, assessing the level of correlation between anamnestic and clinical data (skin phototype, frequency of sunscreens) and the extent of neoplasms on the skin. Materials and methods. Sixty patients with seborrheic keratosіs were examined on the basis of "University clinic" of Zaporizhzhia State Medical University. Preliminary verification of the diagnosis was performed using visual examination, dermatoscopic examination based on a three-point algorithm in polarized light mode (FotoFinder Bodystudio ATBM (Germany). Clinical examination also included Fitzpatrick assessment of skin phototype, taking into account skin color, eye, hair color, and tendency to form tanning or its complications (burns). Results and discussion. Majority of patients were of II skin phototype – 40 (66.7%) individuals, III – 19 (31.7%), IV – 1 (1.7%). 37 patients (61.6%) with seborrheic keratosіs received skin burns after prolonged exposure to the open sun. The most frequent localizations of keratoma were areas of the head – 23 (38.33%) patients, torso – 17 (28.33%), limbs – 16 (26.67%), neck – 4 (6.67%). Thus, taking into account the areas of maximum ultraviolet exposure – head + neck + limbs – we have the majority of cases (n = 43 (71.7%)) with a possible risk factor in the form of increased insolation on these areas of skin. Only 1 patient lived in a country with increased insolation for 0.5 years. 29 (48.4%) patients never used sunscreens, 19 (31.6%) used them occasionally, and 12 (20%) always used them. Pearson's coefficient (Kp =0.51) and Chuprov's coefficient (Kh =0.50) indicate a moderate relationship between the number of foci and Fitzpatrick skin phototype. The data obtained do not rule out an association between the level of lesion foci dissemination and skin features to the perception of tanning. The association coefficient was 0.714 and the contingency coefficient was 0.4. Consequently, this suggests that the association between the use/non-use of sunscreen and the multiplicity of keratosis foci is significant. These data have not been highlighted in previous studies, so we believe that this is an additional argument for the mandatory use of sunscreen. Regular use of sunscreeens has really a significant protective potential for the occurrence of new skin formations, as well as their clinical dissemination. Conclusion. Ultraviolet radiation may be a predictor of multiple foci of keratosis. It is important to comprehensively examine patients with seborrheic keratosіs, focusing on evaluation of skin phototype, history of outdoor exposure, and sunbathing habits. The use of sunscreen remains the unequivocal leader in the prevention of multiple seborrheic keratosis
