Bullous Impetigo

Aka: Bullous Impetigo

1. See Also
   1. NonBullous Impetigo
2. Epidemiology
   1. Represents 10-30% of Impetigo cases
   2. Affects infants (esp. newborns) and young children
   3. Less contagious than NonBullous Impetigo
3. Pathophysiology
   1. Staphylococcal toxin-mediated reaction
   2. Staphylococcal Infection with Phage Group 2
      1. Local variant of Staphylococcal Scalded Skin Syndrome
4. Symptoms: Systemic symptoms in less typical cases
   1. Fever
   2. Diarrhea
5. 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
6. 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
      2. Stevens-Johnson Syndrome
      3. Bullous Pemphigoid
      4. Pemphigous vulgaris
7. Management
   1. See Impetigo
8. Course
   1. Self-limited, non-scarring
   2. Resolves within weeks
9. References
   1. Cole (2007) Am Fam Physician 75(6):859-68
   2. Brown (2003) Int J Dermatol 42:251-5