From the Guidelines
Impetigo is primarily triggered by bacterial skin infections, most commonly caused by Staphylococcus aureus or Streptococcus pyogenes, as evidenced by the 2014 update by the Infectious Diseases Society of America 1. The main triggers for impetigo include:
- Skin trauma such as cuts, scrapes, insect bites, or burns that create entry points for bacteria
- Pre-existing skin conditions like eczema, dermatitis, or chickenpox that compromise the skin barrier, making infection more likely
- Poor hygiene practices that contribute significantly, as bacteria thrive in unclean environments
- Environmental factors such as hot, humid weather that increase sweating and skin maceration, creating favorable conditions for bacterial growth
- Close contact with infected individuals that facilitates transmission, making impetigo common in settings like schools, daycares, and sports teams
- Weakened immune systems due to illness, medication, or chronic conditions that increase susceptibility
According to the study by the Infectious Diseases Society of America 1, impetigo can be either bullous or nonbullous, with bullous impetigo caused by strains of S. aureus that produce a toxin that cleaves the dermal-epidermal junction, and nonbullous impetigo caused by infections with β-hemolytic streptococci or S. aureus, or both in combination. The most effective way to prevent impetigo is to keep skin clean and intact, practice good hygiene, avoid sharing personal items, and promptly treat skin injuries and underlying skin conditions, as supported by the evidence 1. Early treatment with topical antibiotics like mupirocin for mild cases or oral antibiotics such as cephalexin or dicloxacillin for more severe infections can prevent spread and complications.
From the FDA Drug Label
INDICATIONS AND USAGE Mupirocin ointment, 2% is indicated for the topical treatment of impetigo due to: Staphylococcus aureus and Streptococcus pyogenes. The FDA drug label does not answer the question.
From the Research
Triggers for Impetigo
The triggers for impetigo, a common superficial bacterial infection of the skin, include:
- Minor breaks in the cutaneous surface, allowing bacterial invasion 2
- Preexisting dermatosis or infestation, which can become secondarily infected 2
- Insect bites, eczema, or herpetic lesions, which can provide a portal of entry for bacteria 3
- Skin-to-skin contact with an infected person, facilitating the spread of the infection 4, 3
Bacterial Causes
The principal pathogens implicated in impetigo include:
- Staphylococcus aureus, which can cause both nonbullous and bullous impetigo 4, 3, 2, 5
- Streptococcus pyogenes, which is often associated with nonbullous impetigo 4, 3, 6, 5
Other Factors
Other factors that may contribute to the development of impetigo include: