What is the diagnosis and treatment for Impetigo?

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Last updated: April 21, 2025View editorial policy

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From the Guidelines

Impetigo should be treated with either topical mupirocin or retapamulin twice daily for 5 days for bullous and nonbullous cases, as this approach has been shown to be effective in managing the infection. The treatment of impetigo depends on the severity and extent of the infection, with topical antimicrobials being suitable for limited cases and oral therapy recommended for patients with numerous lesions or in outbreaks affecting several people to help decrease transmission of infection 1.

Key Considerations

  • Gram stain and culture of the pus or exudates from skin lesions can help identify the cause of impetigo, but treatment without these studies is reasonable in typical cases 1.
  • Oral therapy for ecthyma or impetigo should be a 7-day regimen with an agent active against S. aureus, such as dicloxacillin or cephalexin, unless cultures yield streptococci alone, in which case oral penicillin is recommended 1.
  • When MRSA is suspected or confirmed, doxycycline, clindamycin, or sulfamethoxazole-trimethoprim (SMX-TMP) is recommended for oral therapy 1.

Management Strategies

  • Topical mupirocin or retapamulin twice daily for 5 days is recommended for bullous and nonbullous impetigo 1.
  • Oral antibiotics, such as cephalexin or dicloxacillin, for 7 days may be necessary for more extensive cases or outbreaks 1.
  • Good hygiene practices, including washing the affected areas gently with soap and water, using separate towels and washcloths, and frequent handwashing, are essential to prevent the spread of infection.

From the FDA Drug Label

The efficacy of topical mupirocin ointment in impetigo was tested in two studies. CLINICAL STUDIES The efficacy of topical mupirocin ointment in impetigo was tested in two studies. In the first, patients with impetigo were randomized to receive either mupirocin ointment or vehicle placebo t.i. d. for 8 to 12 days. Mupirocin ointment, 2% is indicated for the topical treatment of impetigo due to: Staphylococcus aureus and Streptococcus pyogenes.

Impetigo Treatment: Mupirocin ointment is indicated for the topical treatment of impetigo due to Staphylococcus aureus and Streptococcus pyogenes 2 2.

  • Clinical Efficacy Rates:
    • 71% for mupirocin ointment (n=49) in the first study
    • 93% for mupirocin ointment (n=29) in the second study
    • 96% for mupirocin ointment (n=27) in pediatric patients in the second study
  • Pathogen Eradication Rates:
    • 94% for mupirocin ointment in the first study
    • 100% for mupirocin ointment in the second study Mupirocin ointment is effective in treating impetigo, with high clinical efficacy and pathogen eradication rates 2.

From the Research

Definition and Types of Impetigo

  • Impetigo is a common superficial bacterial infection of the skin, with a global disease burden of greater than 140 million 3.
  • There are two principal types: nonbullous (70% of cases) and bullous (30% of cases) 4, 3.
  • Nonbullous impetigo, or impetigo contagiosa, is caused by Staphylococcus aureus or Streptococcus pyogenes, and is characterized by honey-colored crusts on the face and extremities 4.
  • Bullous impetigo, which is caused exclusively by S. aureus, results in large, flaccid bullae and is more likely to affect intertriginous areas 4.

Diagnosis and Treatment

  • The diagnosis of impetigo is usually made clinically, but rarely a culture may be useful 5.
  • Treatment includes topical antibiotics such as mupirocin, retapamulin, and fusidic acid 4, 5.
  • Oral antibiotic therapy can be used for impetigo with large bullae or when topical therapy is impractical 4, 5.
  • Amoxicillin/clavulanate, dicloxacillin, cephalexin, clindamycin, doxycycline, minocycline, trimethoprim/sulfamethoxazole, and macrolides are options, but penicillin is not 4.

Complications and Resistance

  • Complications of impetigo are rare, but can occur, with the most serious being poststreptococcal glomerulonephritis 4, 3.
  • Rising rates of bacterial resistance to standard treatment regimens should inform treatment decisions 3, 6, 7.
  • There is a need for new topical antimicrobials and antiseptics as an alternative treatment strategy to combat increasing antimicrobial resistance 6, 7.
  • The appropriate use of topical ozenoxacin can help eradicate impetigo while minimizing antimicrobial resistance 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Impetigo.

Advanced emergency nursing journal, 2020

Research

Impetigo: diagnosis and treatment.

American family physician, 2014

Research

Diagnosis and treatment of impetigo.

American family physician, 2007

Research

Impetigo: A need for new therapies in a world of increasing antimicrobial resistance.

Journal of clinical pharmacy and therapeutics, 2018

Research

Treatment of Impetigo and Antimicrobial Resistance.

Journal of drugs in dermatology : JDD, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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