Evaluation of Systemic Pharmacotherapy in Bacterial Skin Infections: Adherence to Clinical Guidelines and Factors Associated with Treatment Outcomes

Background: Bacterial skin infections frequently require systemic antibiotic therapy, and adherence to clinical guidelines is important for optimizing treatment outcomes and antimicrobial stewardship. This study evaluated systemic pharmacotherapy for bacterial skin infections, guideline adherence, and factors associated with treatment outcomes. Materials and Methods: This retrospective observational study included 300 patients treated in a regional hospital in Kosovo between January 2025 and August 2026. Demographic, clinical, laboratory, microbiological, and pharmacotherapeutic data were obtained from medical records. Guideline adherence and clinical outcomes were evaluated, and Firth penalized multivariable logistic regression was used to identify factors independently associated with guideline non-adherence and unfavorable clinical outcomes. Results: Guideline-adherent pharmacotherapy was documented in 269 patients (89.7%), while 266 (88.7%) achieved a favorable clinical outcome. Guideline non-adherence was independently associated with younger age (AOR 0.89 per year; 95% CI 0.83–0.95; p < 0.001), female sex (AOR 2.44; 95% CI 1.05–5.98; p = 0.038), higher CRP (AOR 1.23 per 10 mg/L increase; 95% CI 1.11–1.38; p < 0.001), and antibiotic modification (AOR 3.29; 95% CI 1.37–7.89; p = 0.008). Unfavorable clinical outcomes were independently associated with male sex (AOR 4.37; 95% CI 1.84–11.40; p < 0.001), higher CRP (AOR 1.22 per 10 mg/L increase; 95% CI 1.09–1.37; p < 0.001), intravenous administration (AOR 3.06; 95% CI 1.29–7.63; p = 0.011), and guideline non-adherence (AOR 3.12; 95% CI 1.16–8.23; p = 0.025). Conclusions: Guideline adherence and favorable clinical outcomes were high. Nevertheless, non-adherence remained independently associated with unfavorable outcomes, while higher CRP was associated with both study outcomes. These findings support continued optimization of systemic antibiotic pharmacotherapy and antimicrobial stewardship in dermatological practice.