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Blistering skin conditions

Author: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1997. Updated September 2015. 

Blistering skin conditions — codes and concepts

What is a blistering disease?

A blistering disease is a condition in which there are fluid-filled skin lesions.

  • Vesicles are small blisters less than 5 mm in diameter.
  • A bulla is a larger blister. Note that the plural of bulla is bullae.
  • Blisters may break or the roof of the blister may become detached forming an erosion. Exudation of serous fluid forms crust.

Blistering diseases

Acute blistering diseases

Acute blistering diseases can be generalised or localised to one body site and are due to infection or inflammatory disorders. Although most commonly eczematous, generalised acute blistering diseases can be life-threatening and often necessitate hospitalisation.

 Acute blistering conditions should be investigated by taking swabs for bacterial and viral culture. A skin biopsy may be helpful in making a diagnosis.

Acute generalised blistering diseases

Acute febrile neutrophilic dermatosis 

Atypical enterovirus infection 

  • Widespread vesicular eruption
  • Clears in a few days
  • When affecting areas of atopic eczema, enteroviral infection is called eczema coxsackium.


  • Childhood illness; more serious in adults
  • Scalp, face, oral mucosa, trunk
  • Culture/PCR Herpes varicella zoster

Eczema herpeticum 


Polymorphic light eruption 

  • Affects body sites exposed to the sun (hands, upper chest, feet
  • Papules, plaques, sometimes targetoid
  • May spare face
  • Arises within hours of exposure to bright sunlight

Erythema multiforme 

  • A reaction, eg to infection
  • An acute eruption of papules, plaques, target lesions
  • Acral distribution: cheeks, elbows, knees, hands, feet
  • May have mucositis (lips, conjunctiva, genitals)

Stevens-Johnson syndrome / toxic epidermal necrolysis

  • Patient very unwell
  • Mucosal involvement
  • Nearly always drug-induced
  • Rarely due to mycoplasma infection
  • Painful red skin may come off in sheets or have multiple coalescing blisters

Drug hypersensitivity syndrome 

  • Drug started up to 8 weeks prior to the onset
  • Morbilliform eruption that may blister (without necrolysis)
  • Often, mucosal involvement
  • Multiorgan damage (renal, hepatic, respiratory, haematological)
  • Often, marked eosinophilia

Staphylococcal scalded skin syndrome 

Acute localised blistering diseases

Acute dermatitis

Bullous impetigo 


  • Fingers, toes
  • Exposed to cold
  • Purplish tender plaques

Enteroviral vesicular stomatitis 

Clears in a few days 


Fixed drug eruption 

  • Recurring rash, often in the same site
  • Due to an intermittent drug that has been taken within 24 hours of the rash appearing
  • Single or few lesions
  • Central blister

Herpes simplex

  • Monomorphic, umbilicated
  • Culture/PCR Herpes simplex

Herpes zoster (shingles) 

  • Dermatomal
  • Culture/PCR Herpes zoster

Insect bites and stings


  • Central trunk
  • Sweat rash
  • Vesicles are very superficial

Necrotising fasciitis 

Transient acantholytic dermatosis 

  • Acute or chronic
  • Elderly males
  • Itchy or asymptomatic
  • Crusted papules


Chronic blistering diseases

Diagnosis of chronic blistering diseases often requires skin biopsy for histopathology and direct immunofluorescence. A blood test for specific antibodies (indirect immunofluorescence) may also prove helpful in making the diagnosis of an immunobullous disease.

Blistering genodermatoses

Epidermolysis bullosa 

  • Various types
  • Onset at birth or early childhood

Fogo selvagem

  • Also called endemic pemphigus foliaceus
  • Onset at childhood or adolescence 


  • Various types
  • Often, onset in childhood

Benign familial pemphigus 

  • Also called Hailey-Hailey disease
  • Confined to flexures

Blistering genodermatoses

Chronic acquired blistering

Bullous systemic lupus erythematosus

  • Patient has systemic lupus erythematosus
  • Subepidermal bullae

Bullous pemphigoid 

  • Mainly cutaneous (rarely mucosal)
  • Mostly affects the elderly (rarely infants, children)
  • Often associated stroke or dementia
  • Subepidermal bullae
  • Eczematous or urticarial precursors

Dermatitis herpetiformis 

  • Associated gluten-sensitive enteropathy
  • Intensely itchy; vesicles often removed by scratching leaving erosions
  • Symmetrical on scalp, shoulders, elbows, knees, buttocks

Chronic acquired blistering

Other immunobullous diseases

Porphyria cutanea tarda 

  • Metabolic photosensitivity
  • Skin fragility, bullae, milia
  • Dorsum of hands, face
  • Onset in middle age

Other immunobullous diseases


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