Clinical and Inflammatory Predictors of Treatment Failure in Uncomplicated Skin and Soft Tissue Infections: A Multicenter Study From Türkiye

Background Uncomplicated skin and soft tissue infections (uSSTIs) are common, yet predictors of outpatient treatment failure leading to hospitalization remain understudied. This study aimed to identify clinical and laboratory factors associated with hospitalization in uSSTIs. Methods A prospective, multicenter observational study was conducted across 24 infectious diseases departments in Türkiye from April 1 to September 30, 2024. Adult uSSTI patients were included with recorded demographics, comorbidities, clinical and laboratory data. Multivariable logistic regression identified independent predictors of hospitalization following outpatient treatment failure. Results Of 599 patients, 263 completed outpatient therapy, 169 were hospitalized at presentation, and 167 required hospitalization after initial outpatient treatment. Univariate analysis identified higher body mass index (BMI, P  = .015), chronic kidney disease ( P  = .044), immunodeficiency ( P  = .026), insect bite etiology ( P  = .047), and smoking ( P  = .019) as associated with hospitalization. Clinical predictors included preseptal cellulitis ( P  < .001), lesion size > 10% body surface area (BSA, P  < .001), and elevated pulse rate ( P  < .001). Laboratory predictors included elevated neutrophil-to-lymphocyte ratio (NLR > 4.37, P  < .001), C-reactive protein (CRP > 67.5 mg/L, P  < .001), and other inflammatory markers. Multivariable analysis confirmed smoking (OR: 3.403, 95% CI: 1.535–7.542), preseptal cellulitis (OR: 42.354, 95% CI: 4.178–429.336), lesion size > 10% BSA (OR: 3.898, 95% CI: 1.598–9.509), elevated CRP (OR: 1.005, 95% CI: 1.001–1.008), NLR (OR: 1.073, 95% CI: 1.012–1.138), and pulse rate (OR: 1.027, 95% CI: 1.004–1.051) as independent predictors. Conclusions Smoking, preseptal cellulitis, extensive lesions, and elevated NLR, CRP, and pulse rate predict hospitalization in uSSTIs. Early identification may guide initial management, favoring intravenous therapy in high-risk patients to reduce treatment failure.