Medical Specialties: Dermatology, Family practice, Internal medicine, Pediatrics

Clinical Definition

Impetigo is a common, superficial dermatologic infection that is highly contagious, typically caused by Streptococcus (strep) or Staphylococcus (staph) bacteria. Typically, impetigo affects young children, ages 2-6. Blister-like sores form, sometimes filling with pus or yellow fluid, and can result in scabs. 

In Our Own Words

Impetigo is the most common skin infection in children seeing primary care physicians, but it can occur at any age. It appears on the skin as blister-like sores that spread when scratched, accompanied by redness, yellow pus, seepage, and yellow-tan crust formation.


It is caused by skin bacteria, usually ''staph'' or ''strep,'' and is very contagious until the rash disappears, the scabs fall off, or the affected person has finished at least two full days of antibiotics.  Some topical treatments can be as good as oral treatment with antibiotics, but treatment decisions tend to be made case-by-case.  While easily cured, impetigo can return in small children. Good hygiene measures may help reduce the risk of infection.

Relevant Conditions
Common Types
  • Nonbullous
  • Bullous
Side Effects
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  • Koning, S. "Interventions for impetigo." Cochrane Database of Systematic Reviews 2012; Issue 1. Accessed September 2013.
  • University of Maryland Medical Center. "Impetigo." Medical Encyclopedia. Nov. 2012. Accessed September 2013.
  • The Cleveland Clinic. "Impetigo." Disorders. Nov. 2012. Accessed September 2013.
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