Risk stratification and outcome of cellulitis admitted to hospital

Summary

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 ≥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.

Introduction

Superficial soft-tissue infections that involve the skin (erysipelas) or spread to the subcutaneous tissue (cellulitis) are characterized by erythema, swelling, pain, and frequently systemic involvement.¹ The estimated incidence of cellulitis in developed countries is 16.4–24.6/1000 person-years.² Although cases are frequently managed as outpatients,³ cellulitis ranks as the 11th most frequent diagnosis in Australian public hospitals with 73.6 patient days per 10,000 population.⁴ Cellulitis and/or erysipelas are generally not considered severe infections.¹ The mortality of cellulitis/erysipelas in the pre-antibiotic era has been estimated to be 11%.⁵ The all-cause mortality for patients requiring hospital admission for cellulitis today remains considerable, at 5–7.2%.⁶ Complications occurring in patients hospitalised with cellulitis substantially increase health-care costs.4, 7 Factors predictive of mortality and morbidity are not well defined in the literature and the process of devising relevant treatment guidelines and designing appropriate clinical drug trials, in the era of increasing antimicrobial resistance, are impeded.⁵

The present study aimed to evaluate factors associated with mortality, complications and prolonged hospital stay in community-acquired cellulitis requiring hospitalisation. Differences in patient management between Infectious Disease (ID) physicians and other hospital specialities were also analysed.