see also:

• dermatology
• vesicular rashes
• skin necrosis

• bullous rashes are those with large fluid filled superficial cutaneous bullae

• Nikolsky sign
  • applying lateral pressure to an area of normal appearing skin or mucosa causes formation of a blister
  • may be present in epidermolysis bullosa, pemphigus, mucous membrane pemphigoid, lichen planus and lupus erythematosus
• sub-epidermal blisters
  • tense roof which often remain intact
  • eg. bullous pemphigoid, friction blister, dermatitis herpetiformis, erythema multiforme, TEN
• intra-epidermal vesicles
  • thin roofed and leaves denuded skin when ruptures
  • eg. eczema, varicella, Herpes simplex virus (HSV), pemphigus
• subcorneal lesions
  • very thin roof which breaks easily
  • eg. impetigo, miliaria, SSSS

• viral vesicular lesions which usually present as mucosal ulcers:
  • Herpes simplex virus (HSV)
  • hand foot and mouth disease
  • herpangina
  • varicella-zoster virus (chickenpox/shingles)
  • herpes zoster (shingles)
• simple blood blisters:
  • thrombocytopenia
  • angina bullosa hemorrhagica (ABH)
    • characterized by abrupt and unprovoked presentation of blood-filled blister over the oral mucosa
    • usually middle aged persons
    • usually on soft palate
    • usually painless although may have some burning sensation and resolve within days, and may recur intermittently over many years
    • see emedicine
  • amyloidosis
  • the autoimmune disorders listed below may also present with blood filled blisters
• rare, autoimmune disorders:
  • pemphigus
  • bullous pemphigoid
  • gestational pemphigoid
  • cicatrical pemphigoid
  • linear IgA disease

• 1st presentation of chronic blistering condition (see below)
• impetigo
• staphylococcal scalded skin syndrome
• partial thickness burns
• friction blisters
• erythema multiforme
• Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)
• viral vesicular rashes:
  • Herpes simplex virus (HSV)
  • hand foot and mouth disease
  • herpangina
  • varicella-zoster virus (chickenpox/shingles)
  • herpes zoster (shingles)

• bullous pemphigoid
  • an uncommon immunobullous disease where antibodies are found along the basement membrane that lies between the epidermis and dermis on biopsy
  • usually affects middle aged or elderly persons with average age of onset of 65yrs
  • appears to affect ~7 per million people per year and may follow other chronic dermatoses such as lichen planus or psoriasis, while some drugs have been implicated as a cause (eg. non-steroidal anti-inflammatory drugs (NSAIDs), frusemide / furosemide / Lasix, captopril and antibiotics), and some cases may follow UV irradiation or radiotherapy.
  • a non-specific rash may precede blisters by several weeks or months
  • may be localised, often on trunk, limbs, esp. in skin folds
  • rarely is oral but in severe cases may involve all of skin and mucosa is involved in 10-25% of cases
  • healed blisters leave brown pigmented marks or milia but these resolve over a few months
  • various forms:
    • generalised form:
      • most common presentation with tense bullae on any part of skin esp. flexures
    • vesicular form:
      • groups of small, tense blisters, often on an erythematous or urticarial base
    • vegetative form:
      • very uncommon, plaques in intertriginous areas of the skin, such as the axillae, neck, groin, and inframammary areas
    • generalized erythroderma form
      • rare, exfoliative erythroderma which may mimic other conditions such as psoriasis, or atopic dermatitis
    • urticarial form
      • present with persistent urticarial lesions which eventually blister
    • nodular form
      • rare, blisters arising on normal-appearing or nodular lesional skin
    • acral form
      • childood form following vaccinations
      • lesions mainly on palms, soles, and face
    • infant form
      • mainly palms, soles, and face
    • non-bullous pemphigoid
      • these patients have few if any blisters
  • diagnosis
    • if classical, diagnosis may be on clinical grounds alone
    • biopsy of lesion and direct immunofluorescence staining
    • serologic indirect immunofluorescence may show circulating pemphigoid antibodies
  • untreated, it can persist for months or years, with periods of spontaneous remissions and exacerbations
  • Rx is usually needed for 1.5-5yrs and in most cases the condition resolves
  • mortality is same or perhaps up to twice that of normal patients although is mainly higher in those with other co-morbid conditions of the elderly population which may not tolerate the Rx required
  • see dermnetnz
• pemphigus
  • pemphigus vulgaris
    • a rare autoimmune disease that is characterised by blisters and erosions on the skin and mucous membranes, most commonly inside the mouth
    • IgG autoantibodies bind to a protein called desmoglein-3, which is found in desmosomes in the keratinocytes near the bottom of the epidermis
    • may be provoked by sun exposure
    • mainly affects those in their 50's, esp. Jews and Indians, but may affect any race, at any age
    • 1 case per million in NZ
    • 50-70% develop oral lesions
    • other mucosal sites include conjunctiva, oesophagus, labia, vagina, cervix, penis, urethra and anus
    • lesions are painful and slow to heal
    • skin lesions are thin walled flaccid blisters which easily rupture causing painful erosions
    • diagnosis is via biopsy
    • Rx is mainly long term high dose corticosteroids which has reduced mortality from 99% to 5-15% but does not cure the condition
  • pemphigus foliaceus
    • a rare relatively benign form of pemphigus, and also mainly occurs in the 50's but unlike pemphigus vulgaris, there is little or no mucosal involvement.
    • blisters tend to form when the skin is rubbed (Nikolsky sign), and are most common on the trunk
    • autoantibodies (usually IgG) bind to desmoglein-1, which is found in desmosomes in the keratinocytes near the top of the epidermis
    • it may resolve without Rx, or just require topical corticosteroids, although severe cases may require oral doses
    • 6 sub types:
      • pemphigus erythematosus
      • pemphigus herpetiformis
      • endemic pemphigus foliaceus
        • occurs in Sth America where it is called Fogo Selvagem and appears to be triggered by a virus from an insect bite
      • IgA pemphigus foliaceus
      • paraneoplastic pemphigus foliaceus
      • drug-induced pemphigus foliaceus
        • non-steroidal anti-inflammatory drugs (NSAIDs), ACE inhibitors, nifedipine, penicillamine
• pemphigoid gestationis
• cicatricial pemphigoid
  • usually elderly; severe blistering of mucosa, including eyes, genitals, resulting in scarring
  • see dermnetnz
• dermatitis herpetiformis
  • rare, usually young adults with coeliac disease
  • very itchy papules and vesicles, esp. scalp, shoulders, buttocks, elbows and knees
• amyloidosis
• Hailey-Hailey disease - rare, hereditary
• epidermolysis bullosa - rare, hereditary, 10-50 cases per million births
• epidermolysis bullosa acquisita
  • rare, 3 main forms
  • tense vesicles and bullae, and erosions primarily on trauma-prone areas such as the extensor surfaces of hands, knuckles, elbows, knees, and ankles, while blisters on mucus membranes rupture easily
  • generalized inflammatory form is not localised to trauma-prone sites
  • a mucosal variant clinically resembles mucous membrane pemphigoid and can result in significant mucosal scarring and dysfunction
• linear IgA dermatosis (LAD)
  • rare, autoimmune, childhood (typically lower abdomen and anogenital but also, hands, feet, peri-oral and oral) and adult forms (less anogenital/perioral lesions)
  • often have ocular symptoms
• chronic bullous dermatosis of childhood
• dyshidrosis
• bullous systemic lupus erythematosus (BSLE)
  • occurs in patients with systemic lupus erythematosus (SLE)
  • see emedicine
• etc