Rationale and Objectives
Cellulitis is a common cause for emergency department (ED) presentation and subsequent hospital admission. Underlying fracture, osteomyelitis, or foreign body is often considered in the clinical evaluation of these patients. Accordingly, plain radiographs (XRs) of the affected extremity are often ordered during the initial work-up. The utility of these imaging studies in the treatment of uncomplicated lower-extremity cellulitis, however, remains unclear. In an effort to treat this common problem more efficiently, we evaluated our imaging practices and results in a cohort of consecutive patients admitted to a large public city hospital for treatment of uncomplicated lower-extremity cellulitis.
Materials and Methods
Retrospective cohort study of 288 consecutive ED admissions for treatment of uncomplicated cellulitis, of which 214 met the inclusion criteria for this study. Patient demographics, history, vitals, laboratory values, and test results were evaluated with univariate and multivariate statistical analyses.
Results
XRs of the affected lower extremity were obtained in 158 patients (73.8%). Positive XR findings were present in 19 patients (12.0%) and positively correlated with a history of acute trauma to the extremity ( P < .001) or the presence of a chronic wound ( P < .01). Multivariable logistic regression analysis revealed a history of trauma ( P < .001) or the presence of a chronic wound ( P < .05) to be independent predictors of positive XR findings with relative risks of 6.24 and 2.98, respectively.
Conclusions
The establishment of evidence-based guidelines for the treatment of lower-extremity cellulitis has potential to significantly improve clinical efficiency and reduce cost by eliminating unnecessary testing. Based on our results, patients without a recent history of trauma to the affected extremity or the presence of a chronic wound do not appear to warrant XRs. When applied to our cohort, only 48 of 158 patients had a history of trauma or chronic wound. This means that 110 patients unnecessarily had plain films taken as part of their initial work-up. In a largely uninsured inner city patient population such as this cohort, that extra cost falls on the public hospital system.
Cellulitis is an acute, spreading, pyogenic, inflammation of the skin and underlying soft tissue that is an increasingly common cause for emergency department (ED) presentation and subsequent hospital admission. The number of ED visits for skin and soft tissue infections (SSTIs) has nearly tripled between 1993 and 2005 from 1.2 million to 3.4 million , with the largest relative increases seen in major medical center EDs . In the United States, there was a 29% increase in hospital admissions for SSTIs from 2000 to 2004 , and more than 600,000 hospitalizations for SSTIs were recorded in 2010, representing 3.7% of all hospital admissions .
Underlying fracture, osteomyelitis, deep venous thrombosis, or foreign body is often considered in the differential diagnosis of these patients. Accordingly, plain radiographs (XRs) of the effected extremity are frequently ordered. The utility of XRs in the treatment of uncomplicated lower-extremity cellulitis, however, remains unexamined. In an effort to treat this common problem more efficiently, we evaluated our imaging practices and results in a cohort of consecutive patients admitted to a large public city hospital for treatment of uncomplicated lower-extremity cellulitis.
Materials and methods
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Results
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Table 1
Characteristics of Patients with XR Performed
Characteristic XR No XR_P_ Value n % n % Patients 158 73.8 56 26.1 — Age, y, mean (±SD) 53.4 ±15.0 55.3 ±15.0 .402 Male 128 81.0 44 78.6 .693 Homeless 68 43.0 30 53.6 .174 Length of stay, mean (±SD) 4.5 ±4.3 4.2 ±7.4 .661 BMI, mean (±SD) 28.3 ±7.5 30.3 ±9.4 .107 Diabetes 37 23.4 14 25.0 .811 Venous insufficiency 28 17.7 12 21.4 .541 Arterial insufficiency 8 3.7 0 0.0 .086 Lymphedema 12 7.6 5 8.9 .751 Immunocompromised 8 5.1 2 3.6 .649 Smoker 43 27.2 19 33.9 .341 Alcohol abuse 38 24.1 16 28.6 .503 IV drug use 23 14.6 9 16.1 .785 Psychiatric history 35 22.2 20 35.7.046 CCI, mean (±SD) 3.1 ±2.6 3.4 ±2.4 .464 Bilateral involvement 44 27.8 26 46.4.013 Acute trauma 19 12.0 0 0.0.007 Chronic wound 20 12.6 9 16.1 .521
BMI, body mass index; CCI, Charlson Comorbidity Index; IV, intravenous; SD, standard deviation; XR, plain radiograph.
Bold P values denote statistical significance.
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Table 2
Positive XR Findings
Finding n % Total 19 — Fracture 7 36.8 Osteomyelitis 6 31.6 Hardware 4 21.1 Foreign body 1 5.3 Subcutaneous gas 1 5.3
XR, plain radiograph.
Table 3
Positive XR Patient Characteristics
Characteristic Negative XR Positive XR_P_ Value n % n % Patients 139 — 19 — — Age, y, mean (±SD) 52.7 ±14.7 57.7 ±17.1 .181 Male 116 83.5 12 63.2.034 Homeless 63 45.3 5 26.3 .142 Length of stay, mean (±SD) 4.2 ±4.1 6.5 ±5.6.026 BMI, mean (±SD) 28.7 ±6.3 25.1 ±6.3 .053 Diabetes 31 22.3 6 31.6 .37 Venous insufficiency 23 16.5 5 26.3 .296 Arterial insufficiency 5 3.6 3 15.8 .056 Lymphedema 12 8.6 0 0.0 .363 Immunocompromised 7 5.0 1 5.3 .966 Smoker 39 28.1 4 21.1 .596 Alcohol abuse 33 23.7 5 26.3 .805 IV drug use 19 13.7 4 21.1 .392 Psychiatric history 32 23.0 3 15.8 .571 CCI, mean (±SD) 3 ±2.5 3.6 ±3.4 .346 Bilateral involvement 40 28.8 4 21.1 .593 Acute trauma 12 8.6 7 36.8<.001 Chronic wound 14 10.1 6 31.6.008
BMI, body mass index; CCI, Charlson Comorbidity Index; IV, intravenous; SD, standard deviation; XR, plain radiograph.
Bold P values denote statistical significance.
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Table 4
Multivariable ∗ Logistic Regression Analysis of Positive XR Findings
Characteristic RR 95% CI_P_ Value Trauma6.24 2.26 17.2 <.001 Chronic wounds2.98 1.13 7.87 <.05 Arterial insufficiency 0.68 0.17 2.69 .581 Charlson Comorbidity Index (per point) 1.08 0.9 1.31 .413 BMI Average (20–29.9) Reference — — — Underweight (<20) 1.2 0.4 3.58 .74 Obese (30+) 0.54 0.18 1.58 .261 Male gender 0.49 0.2 1.21 .123
BMI, body mass index; CI, confidence interval; RR, relative risk; XR, plain radiograph.
Bold values signify statistically significant increased relative risk (RR).
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Table 5
Multivariable ∗ Logistic Regression Analysis of XR Osteomyelitis
Characteristic RR 95% CI_P_ Value Trauma 6.39 0.26 155 .254 Chronic wound8.62 1.15 64.4 <.05 Diabetes9.05 1.09 75.4 <.05 Arterial insufficiency 4.64 0.24 90 .311 Charlson Comorbidity Index (per point) 0.88 0.58 1.35 .564 Age (per point)1.09 1.02 1.17 <.05
BMI, body mass index; CI, confidence interval; RR, relative risk; XR, plain radiograph.
Bold values signify statistically significant increased relative risk (RR).
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Discussion
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References
1. Pallin D.J., Egan D.J., Pelletier A.J., et. al.: Increased US emergency department visits for skin and soft tissue infections, and changes in antibiotic choices, during the emergence of community-associated methicillin-resistant Staphylococcus aureus. Annals of emergency medicine 2008; 51: pp. 291-298.
2. Hersh A.L., Chambers H.F., Maselli J.H., et. al.: National trends in ambulatory visits and antibiotic prescribing for skin and soft-tissue infections. Archives of internal medicine 2008; 168: pp. 1585-1591.
3. Edelsberg J., Taneja C., Zervos M., et. al.: Trends in US hospital admissions for skin and soft tissue infections. Emerging infectious diseases 2009; 15: pp. 1516-1518.
4. Phoenix G., Das S., Joshi M.: Diagnosis and management of cellulitis. Bmj 2012; 345: pp. e4955.
5. Charlson M.E., Pompei P., Ales K.L., et. al.: A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. Journal of chronic diseases 1987; 40: pp. 373-383.
6. Turecki M.B., Taljanovic M.S., Stubbs A.Y., et. al.: Imaging of musculoskeletal soft tissue infections. Skeletal radiology 2010; 39: pp. 957-971.
7. Blankenship R.B., Baker T.: Imaging modalities in wounds and superficial skin infections. Emergency medicine clinics of North America 2007; 25: pp. 223-234.