• Clinical science

Skin and soft tissue infections


Skin and soft tissue infections comprise a group of heterogeneous conditions that primarily develop as a result of pathogens infiltrating the skin via minor injuries. Most skin infections are caused by Staphylococcus, but they may also be caused by Streptococcus or mixed infections in select cases. Risk factors include diabetes mellitus, immunodeficiency, and chronic edema. Skin and soft tissue infections primarily present as painful, warm, erythematous skin lesions. Systemic symptoms, such as fever and malaise, may also occur. Elevated inflammatory markers in the blood support the clinical diagnosis. Imaging may be considered to establish the extent and localization of infection. Treatment includes antibiotic therapy and immobilization of the affected area while severe cases and abscesses require surgery (debridement or incision and drainage). With the exception of necrotizing fasciitis, the majority of cases respond well to treatment and have a favorable prognosis. In the event of generalization, sepsis and spread of infection to local and distant sites may result.



Treatment of skin and soft tissue infections

  • Management principles
    • Antibiotic treatment
    • Supportive measures
      • Bed rest
      • Pain relief
    • Surgery:
      • Incision and drainage
      • Surgical debridement
Mild infection Moderate infection Severe infection
Nonpurulent infections (erysipelas, cellulitis, necrotizing fasciitis)
  1. Surgical debridement (with culture and sensitivity testing)
  2. Empiric antibiotic treatment: vancomycin PLUS piperacillin/tazobactam[1]
Purulent infections (furuncle, carbuncle, abscess)
  • Incision and drainage
  1. Incision and drainage
  2. Empiric antibiotic treatment: TMP/SMX or doxycycline
  1. Incision and drainage
  2. Empiric antibiotic treatment covering MRSA: vancomycin or daptomycin or linezolid

Adapt antibiotic treatment according to the results of the culture and sensitivity testing.


Differential diagnoses

Pathogen Tissue involvement Clinical features
  • Superficial dermis and lymphatic vessels
  • Rapidly spreading infection; erythematous skin lesion with indistinct margins
  • May present with or without purulent exudate
Necrotizing fasciitis
  • Deeper tissue, fascia, muscles
  • Severe, rapidly progressive infection with necrosis; crepitus, bullae, and purple skin discoloration
  • High risk of systemic complications; high mortality
Skin abscess
  • Deeper layers of the skin
  • Walled-off infection with a collection of pus
Staphylococcal scalded skin syndrome

The differential diagnoses listed here are not exhaustive.



Skin abscess



The most common portal of entry for the pathogen is through a small skin lesion (e.g., interdigital tinea pedis)!

  • Clinical features
    • Location: lower limbs (80% of cases), face
    • Sudden onset; tender, sharply demarcated skin lesion, with erythema, edema, and warmth
    • Lymphangitis; : Red streaks radiating from the skin lesion, extending along the course of the lymphatic vessels, and lymphadenitis (swollen, tender regional lymph nodes) may be present.
    • Systemic symptoms: fever, chills, nausea, headaches, muscle and joint pain




Necrotizing fasciitis

Necrotizing fasciitis is a life-threatening condition!


Ecthyma gangrenosum

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last updated 01/18/2019
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