impetigo%20-and-%20ecthyma
IMPETIGO & ECTHYMA
Impetigo is a very contagious, superficial, bacterial skin infection that easily spreads among people in close contact.
Most cases occur in children and resolve spontaneously without scarring in approximately 14 days.
Ecthyma is a deeply ulcerated form of impetigo that extends to the dermis.
It has "punched-out" ulcers with yellow crust and elevated violaceous margins.
Most cases occur in children and elderly.
It may be a de novo infection or superinfection.

Introduction

Impetigo (Nonbullous)

  • Most common form of impetigo
  • Also known as crusted impetigo or impetigo contagiosa
  • Most common in children 2-5 years of age

Impetigo (Bullous)

  • Newborns & younger children are commonly affected

Ecthyma

  • Typically occurs in children 6 months-18 years, in the elderly, immunocompromised [eg neutropenia, human immunodeficiency virus (HIV)], or patients w/ diabetes mellitus (DM) 

Definition

Impetigo

  • A very contagious, superficial, bacterial skin infection that easily spreads among people in close contact
  • Most cases occur in children & resolve spontaneously w/o scarring in approximately 14 days

Ecthyma

  • Deeply ulcerated form of impetigo that extends to the dermis
    • “Punched-out” ulcers w/ yellow crust & elevated violaceous margins

Etiology

Impetigo (Nonbullous)

  • S aureus & group A beta-hemolytic streptococci (GABS)

Imptetigo (Bullous)

  • Always caused by coagulase-positiveS aureus
    • A localized form of staphylococcal scalded skin syndrome

Ecthyma

  • Group A beta-hemolytic streptococci (Streptococcus pyogenes); S aureus is typically cultured from the lesions but is usually a secondary pathogen

Signs and Symptoms

Impetigo (Nonbullous)

  • Initially presents w/ macules or papules that quickly become small vesicles
    • Vesicles quickly pustulate & rupture leaving an erosion or clusters of erosion
    • Purulent discharge dries & forms honey-colored crusts
  • Usually asymptomatic though local adenopathy is common; pruritus or pain may occur occasionally
  • Lesions are typically found on exposed areas of the skin on the face (especially around the nose & mouth) & extremities
  • Carrier state: 4% of adults may be asymptomatic carrier

Impetigo (Bullous)

  • Newborns & younger children are commonly affected
  • Lesions (0.5-3 cm in diameter) typically develop on intact skin & begin as vesicles that turn into flaccid bullae that contain yellow serous fluid
    • Bullae rupture easily & a moist red-surfaced erosion appears surrounded by a thin rim of scale, which then forms a thin varnish-like light brown crust
  • Generally, there is no surrounding erythema but may have regional lymphadenopathy, pain or systemic symptoms
  • Lesions are often multiple, rapidly spread, & typically found on the face, buttocks, perineum & extremities,the trunk more frequently affected; in neonates, around the diaper area

Ecthyma

  • Lesions initially appear as pustules & vesicles that become ulcerated
    • Ulceration is frequently covered by adherent crusts
  • Associated w/ pain & lymphadenopathy; heals w/ scarring
  • Lesions are usually found on the legs

Risk Factors

Impetigo (Nonbullous)

  • Poor hygiene; warm climate; crowding; preceding skin breaks in the affected area from insect bites, wounds, viral infections (chicken pox, herpes simplex), scabies or burns; prior skin disease eg eczema, atopic dermatitis

Ecthyma

  • Insect bites, scabies, pediculosis, poor hygiene & malnutrition, heat & high humidity
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