OBJECTIVES: To identify risk factors associated with mortality and adverse outcome of community acquired cellulitis/erysipelas requiring hospital admission.METHODS: A retrospective analysis of 395 episodes of cellulitis/erysipelas admitted to a tertiary referral hospital between January 1999 and December 2006.RESULTS: Mortality was 2.5% (10/395). There were 112 complications (28.4%). Median hospitalisation was 5 days. Factors independently associated with mortality, adverse outcome and prolonged stay (>7 days) were bacteraemia and albumin <30 g/L. A risk stratification model was designed based on factors independently associated with adverse outcome: altered mental status, neutrophilia/paenia, discharge from the cellulitic area, hypoalbuminaemia and history of congestive cardiac failure. Adverse outcome risk among patients with scores <4, 6-9 and >9 was <20%, 55% and 100%, respectively. All patients who died had admission score >or=4. Factors independently associated with prolonged hospitalisation were: age >60, symptom duration >4 days, hypoalbuminaemia, bacteraemia, isolation of MRSA and time to effective antibiotics >8 h. MRSA was more frequent among patients admitted during 2003-2006 (OR 2.43, 95% CI: 1-12-5.27). Streptococci accounted for most bacteraemia (11/20). Infectious Disease physician input was independently associated with shorter hospitalisation.CONCLUSIONS: Cellulitis/erysipelas requiring hospitalisation confers considerable morbidity and mortality. Clinical markers present on admission can be used to stratify patient risk of mortality and adverse outcome.