Impetigo

Basics

Impetigo is a superficial skin infection seen frequently in children.
- It is one of the most common skin and soft tissue infections observed in pediatrics.
- Pyoderma and impetigo contagiosa are synonyms for impetigo.
Classification
- Primary impetigo: direct bacterial invasion of previously normal skin
- Secondary impetigo: infection at sites of minor skin trauma or underlying conditions
Types of impetigo
- Nonbullous impetigo
  - Most common form, >70% of cases
  - Lesions begin as papules that progress to vesicles surrounded by erythema.
  - Subsequently, the papules mature into pustules that enlarge and break down to form thick, adherent, golden crusts.
- Bullous impetigo
  - Vesicles enlarge to form bullae containing clear yellow fluid, which become darker and more turbid.
  - Ruptured bullae leave a honey-colored crust.
- Ecthyma
  - An ulcerative form of impetigo
  - Lesions extend through the epidermis and deep into the dermis.

Location
- Most frequently in tropical or subtropical regions
- Also prevalent in northern climates during summer months
Age:
- Found most commonly in children aged 2 to 5 years
- Can spread rapidly through child care centers and schools

Staphylococcus aureus: most common etiologic agent. Toxin-producing strains cause cleavage in superficial skin layer.
Impetigo due to community-associated methicillin-resistant S. aureus (CA-MRSA) has occurred in a minority of cases.
β-Hemolytic streptococci (primarily group A, but serogroups C and G have been implicated in some cases)

There's more to see -- the rest of this topic is available only to subscribers.