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Source: Fish DN, Pendland SL, Danziger LH. Skin and Soft-Tissue Infections. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. Accessed July 21, 2012.

  • Superficial skin infection

  • Staphylococcus aureus either alone or in combination with S. pyogenes has emerged as a principal cause of impetigo
    • Bullous form caused by strains of S. aureus.
  • Most cases caused by S. pyogenes.

  • Minor trauma, such as scratches or insect bites, allows organisms to enter superficial layers of skin.

  • Most common in children
  • Bullous form most frequently affects neonates.
    • 10% of all cases
  • Highly communicable and spreads through close contact.
    • Hot, humid weather facilitates microbial colonization of skin.

  • Improved hygiene, especially handwashing

  • Close contact at daycare centers and schools

  • Face is most common site of infection

Signs and Symptoms

  • Pruritus
    • Scratching of lesions may further spread infection through excoriation of skin.
  • Nonbullous impetigo
    • Manifests initially as small, fluid-filled vesicles.
    • Rapidly develop into pus-filled blisters that readily rupture.
    • Purulent discharge dries to form golden yellow crusts characteristic of impetigo.
  • Bullous impetigo
    • Weakness, fever, and diarrhea may be seen.
    • Lesions begin as vesicles.
    • Turn into bullae containing clear yellow fluid.
      • Bullae soon rupture, forming thin, light brown crusts.

Means of Confirmation and Diagnosis

  • Culture of lesions

Laboratory Tests

  • Complete blood counts (CBC): leukocytosis common.
  • Culture purulent material at base of lesion.

Differential Diagnosis

  • Chicken pox

  • Rapid eradication of infection
  • Symptom relief
  • Prevent formation of new lesions.
  • Prevent complications such as cellulitis.

  • Soaking lesions with warm, soapy water provides symptomatic relief and promotes removal of crusts on lesions.

  • Penicillinase-resistant penicillins (e.g., dicloxacillin) are agents of first choice because of increased isolation of S. aureus (Tables 1 and 2).
  • Treat for 7–10 days.

Table 1. Evidence-Based Recommendations for Treatment of Impetigo
Table 2. Recommended Drugs and Dosing Regimens for Outpatient Treatment of Mild ...

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