Vesiculobullous rashes

(Redirected from Bulla)


  • Vesiculobullous disorders characterized by involvement of the dermal-epidermal junction (causing fluid-filled lesions to form)

Rash Red Flags[1]

Dermatology Nomenclature

Small lesions (<0.5cm)

Name Raised/Palpable Fluid-Filled Other Description Diagram
Macule No None flat, cirumscribed, colored Macule.png
Papule Yes None Solid Papule.png
Vesicle Yes Clear Vesicles (2).png
Pustule Yes Pus Leukocytes or keratin Pustules.png

Large lesions (>0.5cm)

Name Raised/Palpable Fluid-Filled Other Description Diagram
Patch No None Large macule (flat, colored) Patch.png
Plaque Yes None Superficially raised, circumscribed solid area Plaque.png
Nodule Yes None Distinct large papule Nodules.png.png
Bulla Yes Clear Large vesicle/blister or exposed epidermal layer Bulla.png
Wheal Yes Edema Firm and edema of dermis


Ulcer, fissue, and erosion

Clinical Features

  • Vesicles are small (<1cm)
  • Bullae are larger (>1cm)

Vesiculobullous rashes visual diagnosis

Differential Diagnosis

Vesiculobullous rashes




  • Frequently a clinical diagnosis based on ruling-out more dangerous causes
  • See differential diagnosis section (above)
    • Consider whether or not the patient has a fever or is toxic appearing (dangerous diagnosis)
    • Look at lesion distribution


  • Based on presumed cause


  • Based on presumed cause

See Also


  1. Nguyen T and Freedman J. Dermatologic Emergencies: Diagnosing and Managing Life-Threatening Rashes. Emergency Medicine Practice. September 2002 volume 4 no 9.