Bacteria

Bullous Impetigo

search

Bullous Impetigo

  • See Also
  1. NonBullous Impetigo
  • Epidemiology
  1. Represents 10-30% of Impetigo cases
  2. Affects infants (esp. newborns) and young children
  3. Less contagious than NonBullous Impetigo
  4. Most common cause of ulcerative buttock rash in infants
  • Pathophysiology
  1. Unlike NonBullous Impetigo, Bullous Impetigo is caused only by staphyococcus aureus
  2. Staphylococcal toxin-mediated reaction
  3. Staphylococcal Infection with Phage Group 2
    1. Local variant of Staphylococcal Scalded Skin Syndrome
  • Symptoms
  • Systemic symptoms in less typical cases
  1. Fever
  2. Diarrhea
  3. Weakness
  • Signs
  1. Distribution
    1. Intertriginous areas (diaper, axilla, neck)
  2. Characteritics
    1. Onset with vessicles enlarging quickly to bullae
    2. Flaccid bullae, 1-2 cm diameter with sharp margins
      1. No surrounding erythema (unlike nonbullous form)
    3. Bullae break leaving characteristic appearance
      1. Thin yellow serous crust
      2. Small rim of Blister roof at edge of lesion
  3. Pathognomonic Signs (Collarette Sign)
    1. Collar of scale forms around ruptured Blister roof
  • Differential Diagnosis
  1. Common
    1. Contact Dermatitis
    2. Herpes Simplex Virus
    3. Varicella
    4. Insect Bites
    5. Burn Injury (e.g. Cigarette burns)
  2. Uncommon
    1. Bullous variants of other conditions
      1. Erythema Multiforme
      2. Systemic Lupus Erythematosus
      3. Scabies
      4. Fixed Drug Eruption
    2. Stevens-Johnson Syndrome
    3. Bullous Pemphigoid
    4. Pemphigous vulgaris
    5. Dermatitis Herpetiformis
  • Management
  1. See Impetigo
  • Course
  1. Self-limited, non-scarring
  2. Resolves within 2-3 weeks
  • References
  1. Cole (2007) Am Fam Physician 75(6):859-68 [PubMed]
  2. Brown (2003) Int J Dermatol 42:251-5 [PubMed]