Emergency Department Management of Cellulitis and Other Skin and Soft-Tissue Infections (Infectious Disease CME and Pharmacology CME)

Table of Contents

 

About This Issue

Skin and soft-tissue infections are common presentations in the ED, but employing a systematic approach to diagnosis and management will help emergency clinicians choose the best diagnostic and treatment options. In this issue, you will learn:

How to differentiate a skin infection from a chronic condition with similar signs and symptoms.

How the history of the type of exposure can help deduce the likely involved organism and the treatment required.

The differences between superficial versus deeper tissue infections and how that affects treatment decisions.

The signs that put necrotizing infections on the differential, even when there is no gas, crepitus, bullae, or necrosis visible.

The diagnostic testing and imaging orders that can differentiate cellulitis and abscess.

The loop drainage technique for incision and drainage of abscesses.

When antibiotics are needed and which ones to choose.

1. About This Issue
2. Abstract
3. Case Presentations
4. Introduction
5. Critical Appraisal of the Literature
6. Etiology and Pathophysiology
   1. Classifications of Necrotizing Soft-Tissue Infections
7. Differential Diagnosis
8. Prehospital Care
9. Emergency Department Evaluation
   1. History
   2. Physical Examination
10. Diagnostic Studies
    1. Imaging
    2. Laboratory Studies
    3. LRINEC Scoring System
11. Treatment
    1. Reference Guidelines
    2. Considerations in Suspected MRSA Infection
    3. Prescribing Antibiotics After Incision and Drainage of Simple Abscess
    4. Treatment of Necrotizing Soft-Tissue Infection
12. Special Populations
    1. Intravenous Drug Users
    2. Immunocompromised Patients
    3. Diabetic Patients
13. Controversies and Cutting Edge
    1. Wound Irrigation
    2. Wound Packing
    3. Loop Drainage
    4. New Antibiotic Therapies
14. Disposition
15. Summary
16. Time- And Cost-Effective Strategies
17. 5 Things That Will Change Your Practice
18. Risk Management Pitfalls for Emergency Department Patients With Skin and Soft-Tissue Infections
19. Case Conclusions
20. Clinical Pathway for Managing Skin and Soft-Tissue Infections in the Emergency Department
21. Tables and Figures
22. References

Abstract

Cellulitis and other skin and soft-tissue infections (SSTIs) are common presentations in the emergency department. This review describes the varied etiologies and patient presentations of the more common SSTIs: cellulitis, abscesses, and necrotizing soft-tissue infections. A discussion of the common diagnoses masquerading as SSTIs is presented, as well as a stepwise approach to avoiding misdiagnosis. Diagnostic studies are also evaluated, including discussions on ultrasound, computed tomography, and clinical decision rules. This review also provides an evidence-based analysis of the controversies in management of abscesses, including the commonly utilized techniques of incision and drainage, irrigation, packing, and concurrent antibiotic therapy.

Case Presentations

A 35-year-old man presents with a 3-cm circular, slightly raised lesion on his left lower leg that has associated warmth, erythema, and tenderness…

• The patient reports that the lesion appeared 2 days ago, and that he has had similar-appearing lesions in the past.
• He is afebrile and hemodynamically stable, but he said this lesion is causing him moderate discomfort.
• You are concerned for an abscess but are unsure whether there is a significant fluid pocket. What imaging modality can you utilize to confirm your diagnosis at the bedside? What should your management of this patient’s presentation include?

A 72-year-old man with a past medical history of diabetes, obesity, chronic obstructive pulmonary disease, and coronary artery disease presents with vague complaints of malaise and generalized weakness…

• Point-of-care glucose in triage was 402 mg/dL. Presenting vital signs were: heart rate, 88 beats/min; temperature, 37.6ºC; respiratory rate, 16 breaths/min; and oxygen saturation, 97% on room air.
• On examination, his lungs are clear to auscultation, no murmurs are present, and his abdomen is soft and nontender.
• No obvious source of infection is initially apparent on exam, and you begin to exit the room, planning an extensive diagnostic workup. Before leaving, you ask him to undress completely, and you notice that his scrotum and perineum are erythematous, necrotic, with a foul odor and purulent discharge. Given this presentation, what is your immediate concern? What, if any, immediate medical management should be started? Should you call your consultant immediately or wait for labs and imaging to return?

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Clinical Pathway for Managing Skin and Soft-Tissue Infections in the Emergency Department

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Tables and Figures

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Key References

Following are the most informative references cited in this paper, as determined by the authors.

2. * Stevens DL, Bisno AL, Chambers HF, et al. Executive summary: practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infec Dis. 2014;59(2):147-159. (Practice guidelines) DOI: 10.1093/cid/ciu444

3. Mueller A, Sweeny A. Cellulitis disposition: discharge versus admission. 2021. Accessed April 10, 2022. (Review article)

5. * Kilburn SA, Featherstone P, Higgins B, et al. Interventions for cellulitis and erysipelas. Cochrane Database Syst Rev. 2010(6):CD004299. (Cochrane review; 25 randomized controlled trials) DOI: 10.1002/14651858.CD004299.pub2

6. * Spelman D, Baddour LM. Cellulitis and skin abscess: epidemiology, microbiology, clinical manifestations, and diagnosis. 2021. UpToDate. Accessed April 10, 2022. (Review article)

7. * Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011;52(3):e18-e55. (Practice guideline) DOI: 10.1093/cid/ciq146

8. Santistevan J. Necrotizing fasciitis: pearls & pitfalls. 2021. emDocs. Accessed April 10, 2022. (Online review article)

10. Helman A. EM cases: skin and soft tissue infections – myths and misperceptions. 2018. emDocs. Accessed April 10, 2022. (Online review article)

13. * Barbic D, Chenkin J, Cho DD, et al. In patients presenting to the emergency department with skin and soft tissue infections what is the diagnostic accuracy of point-of-care ultrasonography for the diagnosis of abscess compared to the current standard of care? A systematic review and meta-analysis. BMJ Open. 2017;7(1):e013688. (Systematic review and meta-analysis; 8 studies) DOI: 10.1136/bmjopen-2016-013688

22. * Wong CH, Khin LW, Heng KS, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med. 2004;32(7):1535-1541. (Retrospective observational study; 454 patients) DOI: 10.1097/01.ccm.0000129486.35458.7d

27. Wang W, Chen W, Liu Y, et al. Antibiotics for uncomplicated skin abscesses: systematic review and network meta-analysis. BMJ Open. 2018;8(2):e020991. (Systematic review and meta-analysis; 4198 patients) DOI: 10.1136/bmjopen-2017-020991

38. American College of Emergency Physicians. State of the art: observation units in the emergency department. 2021. Accessed April 10, 2022. (ACEP policy resource and education paper)

Subscribe to get the full list of 38 references and see how the authors distilled all of the evidence into a concise, clinically relevant, practical resource.

Keywords: cellulitis, abscess, necrotizing, erysipelas, purulent, MRSA, saltwater, dermatitis, gout, cobblestoning, POCUS, LRINEC, antibiotics, loop, drainage

Points & Pearls Excerpt

• With some 2 million cases of SSTIs presenting to EDs annually, their misdiagnosis and mismanagement leads to hundreds of millions of dollars of avoidable healthcare spending and increased risk for morbidity and mortality.
• SSTIs can be distinguished by their location in the soft tissue: erysipelas is superficial; cellulitis is in the dermal layers; and necrotizing infection is in the deeper dermal and fascial layers. (See Figure 1.)
• Purulent cellulitis is predisposed for Staphylococcus species; the IDSA recommends empiric coverage for MRSA for these patients.
• Nonpurulent cellulitis has a predominance toward infection with Streptococcus species.