Obesity and cellulitis: Associations with infection severity, recurrence, and healthcare utilization—A systematic review

Abstract

Background Obesity is a growing global health concern associated with chronic inflammation, immune dysregulation, and impaired skin barrier function, all of which may increase susceptibility to cellulitis and influence clinical outcomes. This systematic literature review synthesized current evidence examining the relationship between obesity and cellulitis risk, infection severity, and healthcare utilization. Methods This PRISMA 2020-guided systematic review and narrative synthesis searched PubMed/MEDLINE, Embase, CINAHL, and Web of Science for English-language primary studies published from January 2015 through December 2025. Eligible studies involved adults with cellulitis or erysipelas—or adult population cohorts reporting a separable cellulitis/erysipelas-specific outcome—evaluating body mass index (BMI) or obesity as an exposure or predictor. Target outcomes comprised cellulitis development or hospitalization, recurrence, treatment response or failure, severity, length of stay, readmission, cost, and mortality. Given the substantial heterogeneity across study designs and outcome definitions, findings were synthesized narratively. When sufficiently complete primary reports were available, risk of bias was evaluated using design-appropriate Joanna Briggs Institute (JBI) critical appraisal tools (Appendix 4). Results Eighteen primary studies met the eligibility criteria. Across population cohorts and cellulitis-specific clinical studies, higher BMI or obesity was generally associated with greater cellulitis risk (e.g., ORs ranging from 1.11 to 4.7) and, in several studies, recurrence or increased healthcare utilization (such as prolonged length of stay). However, associations were not uniform: some studies reported null findings for treatment failure or readmission. The evidence base was predominantly observational and methodologically heterogeneous, so conclusions regarding downstream clinical outcomes are less certain than those regarding cellulitis risk and incidence. Conclusion Obesity is an important risk marker of cellulitis susceptibility and adverse clinical outcomes. Future studies using standardized outcome measures and improved assessments of adiposity beyond BMI are needed to guide prevention strategies and optimize management of this growing population.