The polymorphism of the genes of the folate cycle was studied. The study identified genes that are presumably involved in the occurrence and development of rosacea, as well as affecting the severity of the disease. Unfavorable variants of the folate metabolism genes: MTHFR: 1298 A>C rs1801131, MTHFR: 677C>T rs1801133. An increase in the level of homocysteine in the blood of patients with rosacea turned out to be significant. The identified loci provide specificity of inflammatory mechanisms in rosacea, and identify potential pathways for therapeutic intervention.