Fast Five Quiz: Staphylococcal Infections

Michael Stuart Bronze, MD


September 08, 2021

Nonpurulent cellulitis is associated with four cardinal signs of infection: erythema, pain, swelling, and warmth. Several physical examination findings may help the clinician identify the most likely pathogen and assess the severity of the infection, thereby facilitating appropriate treatment. These findings include the following:

  • The involved site is red, hot, swollen, and tender.

  • Unlike erysipelas, the borders are not elevated or sharply demarcated.

  • The most commonly involved site is the leg.

  • Regional lymphadenopathy is present.

  • Malaise, chills, fever, and toxicity are present.

  • Skin infection without underlying drainage, penetrating trauma, eschar, or abscess is most likely caused by streptococci; on the other hand, S aureus, often community-acquired MRSA, is the most likely pathogen when these factors are present.

  • Cellulitis characterized by violaceous color and bullae suggests more serious or systemic infection with such organisms as Vibrio vulnificus or Streptococcus pneumoniae.

  • Guidelines from the Infectious Diseases Society of America (IDSA) do not routinely recommend cultures of blood or cutaneous aspirates, biopsies, or swabs in the evaluation of cellulitis.

Read more clinical information on cellulitis.


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