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Flashcards in Blistering Conditions Deck (45)
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How do you categorise Bullous disorders?

  • Genetic - rare
  • Acquired
    • Rare - Immunobullous - affecting epidermis or dermo-epidermal junction.
    • Common - non-immunobullous


What are some non-immunobullous causing of blistering?

  • Herpes Simplex
  • Herpes Zoster
  • Bullous impetigo
  • Insect Bites
  • Burns - friction, cold, hot.
  • Pompholyx
  • Acute contact dermatitis
  • Drugs Reactions
    • Erythema Multiforme
    • Steven Johnson Syndrome
    • Toxic Epidermal Necrolysis.


How do you know if you are dealing with a immunobullous disorder that is attacking below the epidermis?

  • Milia or scarring can occur.
  • The epidermis forms a "roof" or "blanket" over the blister causing it to be tense.


What Immunoglobulins are form against the skin to form autoimmune bullous conditions?

IgG is the most common

And then IgA


What is the extra test (Apart from H&E histology) that is used to differentiate between autoimmune bulous disorders?


It is a method of detecting autoantibodies.


What is the workup for blistering conditions?

  1. Biopsy of skin
  2. H&E histology
  3. Send some perilesional skin for Direct IMF.
  4. Consider sending some serum for indirect IMF.


Tell me the difference between direct and indirect immunofluorescence (DIMF vs IIMF) and how immunofluorescenec applies to autoimmune bullous conditions?

  • Direct Immunofluorescence needs a biopsy
    • Fluoresces green.
  • Indirect Immunofluorescence needs a plasma sample.
    • Useful if disease activity or response to therapy needs to be evaulated or if biopsy can't be taken.
  • Immunofluorescence allows us to see if autoantibodies are being produced and thus see if the condition is an autoimmune bullous condition or not.


What do the autoantibodies target in Pemphigus?

Desmosome - the glue that sticks the epidermal cells together.

They specifically target Desmolein 1 & Desmoglein 3 of the Desmosome.


What is the name for the crumbling of the epidermal cells in Pemphigus?



Describe Nikolsky's sign

It is when a finger is placed over or next to the bullous

Then dragged gently along the skin and part of the epidermis comes off.

It is seen in conditions with epidermal fragility like PEMPHIGUS VULAGARIS


Why are oral ulcers seen in Pemphigus Vulgaris and not Pemphigoid?

Because Desmoglein 3 is found in the oral mucosa and PV targets Desmoglein 1 and 3.


What is this on H&E Histology?

Pemphigus Vulgaris-

split occurs within the epidermis just above the Basement Membrane Zone (suprabasal)


What condition is this on Direct Immunofluorescence?


What is the name of the appearance called?

Pemphigus Vulgaris

You can see the IgG in the intercellular glue attacking desmogleins 1 & 3



What are the 4 types of Pemphigus?

  • Pemphigus VULAGARIS(most common)-autoantibodies to Desmogelins 1 & 3.
  • Pemphigus FOLIACEUS- autoantibodies to Demoglein 1 - oral & mucosal involvement doesn't occur
  • Pemphigus VEGETANS- autoantibodies just to Desmogleins 3
    • Flaccid blisters heal to leave warty plaques in the fissures.
  • PARANEOPLASTIC Pemphigus - persistent oral ulceration on the vermillion border with stomatitis.


How do you treat Pemphigus Vulgaris?

  • Initially high dose Prednisolone 60-80mg OD.
  • Then replace with azathioprine, Mycophenate Mofetil, cyclophosphamides or plasmapheresis.
  • Rituximab (B-Cell Depleter) - soon to be the first line agent.
  • Referral to dermatologist is mandatory.


How can you remember which layers of the skin are affected by Pemphigus and Pemphigoid?

PemphiguS = Superficial

PemphigoiD = Deep


What is the pathophysiology of Bullous Pemphigoid?

IgG autoantibodies target antigens in the Basement Membrane Zone(BMZ) at the Dermo-Epidermal Junction.

C3 is then deposited at the BMZ.

(Direct IMF shows this on immunofluorescence)



In Bullous Pemphigoid, what % of cases are positive for IgG using indirect IMF?



What drugs cause Bullous Pemphigoid?

  • ACE Inhibitors
  • Diuretics
  • Antibiotics


Does drug induced bullous pemphigoid more likely occur in younger or older people?

Younger people


How do you manage Bullous Pemphigoid?

  • Biopsy for H&E & Direct IMF.
  • Indirect IMF can also be sent.
  • Treat secondary infection.
  • Superpotent topical steroids if localised.
  • Usually admitted to hospital and put on oral sterids.
  • Oral steroids are tapered and replaced with steroid sparing agents.
  • Minocycline or Nicotinamide can be helpful.


What is the typical presentation in Bullous Pemphigoid?

  • Elderly patients
  • Either:
    • Pre-Bullous Phase: Urticated lesions & Pruritus.
    • Bullous Phase: Typical tense Bullae on an erythematous urticated base.


If you see Bullous Pemphigoid with oral involvement, what should you consider?

If there is an underlying cancer.


What are 2 other types of Pemphigoid to be aware of?

  • Cicatricial Pemphigoid (aka mucous membrane pemphigoid).
    • Multiple aggresive oral ulcers in middle age.
    • Associated with HLAB12.
  • Pemphigoid or Gestationis - Bullous Pemphigoid in Pregnancy.
    • Usually in the 2nd or 3rd trimester but can be post-partum.
    • Usually start around and involve the umbilicus.
    • Neonate will blister for a few weeks.
    • Managed by Dermatologists and Obstetricians
    • Oral steroids are usually required.
    • Pt's are to avoid the COCP in the future as this can trigger Pemphigoid.


What condition is this?

Epidermolysis Bullosa Acquisita (EBA)

IgG Autoantibodies attack Type 7 Collagen.

Skin bilstering and milia form usually in the hands and extensor surfaces.


What is Epidermolysis Bullosa Acquisita (EBA) associated with?

  • Inflammatory Bowel Disease
  • Haemtological Malignancies
  • Myeloma
  • Lymphoma


In Epidermolysis Bullosa Acquisita (EBA), what does the histology show?

  • Subepidermal blister
  • IMF shows linear IgG at the BMZ.


What other test can be used to differentiate between Epidermolysis Bullosa Acquisita (EBA) and Cicatricial Pemphigoid?

Salt-Split Skin Test

  • The Fluorescent-labelled skin biopsy is immersed in saline.
  • This causes the lamina lucida to split.
  • If EBA - the split occurs on the dermal side of the split.
  • If Cicatrical Pemphigoid - the split is on the epidermal side of the split.


Porphyria Cutanea Tarda can look like Epidermolysis Bullosa Acquisita (EBA). How can you tell the difference betweeen the two conditions?

Histology will be negative in Porphyria Cutanea Tarda.


How does Linear IgA disease manifest clinically?

It presents as a group of blisters around the genitalia, umbilicus and on the face.