Abstract Background The pathogenesis of psoriasis vulgaris involves changes in DNA molecules, genomic instability, telomere attrition, and epigenetic alterations among them. These changes are also considered important mechanisms of aging in cells and tissues. Objective This study dealt with oxidation damage, telomere length and methylation status in DNA originating from peripheral blood of 41 psoriatic patients and 30 healthy controls. Methods Oxidative damage of serum DNA/RNA was determined immunochemically. Real-time PCR was used for the analysis of the telomere length. ELISA technique determined levels of 5-methylcytosine in blood cells' DNA. Results Oxidative damage of serum DNA/RNA was higher in patients than in controls (median, 3758 vs. 2286 pg/mL, p < 0.001). A higher length of telomeres per chromosome was found in patients whole-cell DNA than in controls (3.57 vs. 3.04 kilobases, p = 0.011). A negative correlation of the length of telomeres with an age of the control subjects was revealed (Spearman’s rho = -0.420, p = 0.028). Insignificantly different levels of 5-methylcytosine in patients and controls were observed (33.20 vs. 23.35%, p = 0.234). No influences of sex, smoking, BMI, PASI score, and metabolic syndrome on the methylation status were found. Study limitations i) A relatively small number of the participants, particularly for reliable subgroup analyses, ii) the Caucasian origin of the participants possibly influencing the results of the parameters determined, and iii) Telomerase activity was not directly measured in serum or blood cells. Conclusion The study demonstrated increased levels of oxidized DNA/RNA molecules in the serum of patients with exacerbated psoriasis vulgaris. The results were minimally influenced by sex, the presence of metabolic syndrome, or cigarette smoking. In the psoriatic blood cells' DNA, the authors observed longer telomeres compared to healthy controls, particularly in females. Insignificantly higher global DNA methylation in psoriasis cases compared to the controls indicated marginal clinical importance of this epigenetic test performed in the blood cells' DNA. instability attrition them tissues 4 3 DNARNA RNA immunochemically Realtime Real time 5methylcytosine methylcytosine 5 median, median (median 375 vs 228 pgmL pg mL pg/mL 0.001. 0001 0.001 . 0 001 0.001) wholecell whole cell 3.57 357 57 (3.5 304 04 3.0 kilobases 0.011. 0011 0.011 011 0.011) Spearmans Spearman s 0.420, 0420 420 -0.420 0.028. 0028 0.028 028 0.028) 33.20 3320 33 20 (33.2 2335 23 35 23.35% 0.234. 0234 0.234 234 0.234) sex smoking BMI score i analyses ii iii females 37 22 000 0.00 00 3.5 (3. 3. 0.01 01 0.420 042 42 -0.42 002 0.02 02 33.2 332 2 (33. 233 23.35 023 0.23 0.0 (3 0.42 -0.4 33. (33 23.3 0.2 0. ( 0.4 -0. 23. -0 -