Rosacea: identification of key disease factors and topical therapy with metronidazole

Background. There is a complex interaction of endogenous and exogenous factors in rosacea pathogenesis. Existing methods of analysis often do not consider the multifactorial nature of dermatosis, which complicates effective management of patients. Objective. To identify the main relationships between the development factors and rosacea severity building a Bayesian network model original for this dermatosis, as well as to evaluate the results of topical therapy with metronidazole. Material and methods. The study was performed from 2023 to 2025 in Kazan. It involved 117 patients with papulopustular rosacea, median age 35.0 [24; 45] years. The studied parameters included: unchangeable (general characteristics, anamnestic data) and changeable (laboratory indicators, morphofunctional parameters and microbiota content of the facial skin) factors. Obtained parameters — clinical characteristics and dermatological indices. At the first stage of the study, a reconstruction of non-parametric Bayesian network was carried out using a modified algorithm that ensures reproducibility of the model due to clear threshold criteria (Spearman’s rank correlation coefficient equal 0.7 and above) and cycle elimination stages. At the second stage, a group of patients (n=52) with papulopustular subtype of rosacea of mild and moderate course was formed from the total sample, and these subjects underwent 12-week topical therapy with 1% metronidazole gel. Results. With the use of a new network approach for rosacea, key factors influencing the course of dermatosis were identified, 4 clusters of features describing the influence of hormonal, biochemical, immunohematologic and microbial pathogenesis factors were formed. Topical therapy of patients (n=52) with 1% metronidazole gel was effective in 86.5% (n=45) cases. Adverse local reactions were characterized by a mild degree of severity and did not require withdrawal of the drug. Conclusion. The proposed multicomponent Bayesian rosacea model with methodological reproducibility is useful for understanding the relationships between pathogenesis factors and clinical manifestations of dermatosis. Topical therapy of papulopustular rosacea with 1% metronidazole gel has shown high effectiveness, safety and favorable tolerability.