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Flashcards in Blistering Conditions Deck (45)
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1
Q

How do you categorise Bullous disorders?

A
  • Genetic - rare
  • Acquired
    • Rare - Immunobullous - affecting epidermis or dermo-epidermal junction.
    • Common - non-immunobullous
2
Q

What are some non-immunobullous causing of blistering?

A
  • 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.
3
Q

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

A
  • Milia or scarring can occur.
  • The epidermis forms a “roof” or “blanket” over the blister causing it to be tense.
4
Q

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

A

IgG is the most common

And then IgA

5
Q

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

A

Immunolfuoresence

It is a method of detecting autoantibodies.

6
Q

What is the workup for blistering conditions?

A
  1. Biopsy of skin
  2. H&E histology
  3. Send some perilesional skin for Direct IMF.
  4. Consider sending some serum for indirect IMF.
7
Q

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

A
  • 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.
    *
8
Q

What do the autoantibodies target in Pemphigus?

A

Desmosome - the glue that sticks the epidermal cells together.

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

9
Q

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

A

ACANTHOLYSIS

10
Q

Describe Nikolsky’s sign

A

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

11
Q

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

A

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

12
Q

What is this on H&E Histology?

A

Pemphigus Vulgaris-

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

13
Q

What condition is this on Direct Immunofluorescence?

What is the name of the appearance called?

A

Pemphigus Vulgaris

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

Chicken-Wiring

14
Q

What are the 4 types of Pemphigus?

A
  • 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.
15
Q

How do you treat Pemphigus Vulgaris?

A
  • 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.
16
Q

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

A

PemphiguS = Superficial

PemphigoiD = Deep

17
Q

What is the pathophysiology of Bullous Pemphigoid?

A

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)

18
Q

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

A

70%

19
Q

What drugs cause Bullous Pemphigoid?

A
  • ACE Inhibitors
  • Diuretics
  • Antibiotics
20
Q

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

A

Younger people

21
Q

How do you manage Bullous Pemphigoid?

A
  • 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.
22
Q

What is the typical presentation in Bullous Pemphigoid?

A
  • Elderly patients
  • Either:
    • Pre-Bullous Phase: Urticated lesions & Pruritus.
    • Bullous Phase: Typical tense Bullae on an erythematous urticated base.
23
Q

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

A

If there is an underlying cancer.

24
Q

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

A
  • 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.
25
Q

What condition is this?

A

Epidermolysis Bullosa Acquisita (EBA)

IgG Autoantibodies attack Type 7 Collagen.

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

26
Q

What is Epidermolysis Bullosa Acquisita (EBA) associated with?

A
  • Inflammatory Bowel Disease
  • Haemtological Malignancies
  • Myeloma
  • Lymphoma
27
Q

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

A
  • Subepidermal blister
  • IMF shows linear IgG at the BMZ.
28
Q

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

A

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.
29
Q

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

A

Histology will be negative in Porphyria Cutanea Tarda.

30
Q

How does Linear IgA disease manifest clinically?

A

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

31
Q

This is IgA disease, what is this feature called?

A

String of Pearls Sign

A group of blisters around the edge of an annular configuration.

32
Q

What is seen in immunofluorescence in Linear IgA Disease?

A

Immunofluorescence shows IgA deposition at the dermo-epidermal junction

33
Q

How is Linear IgA disease similar but different to Bullous Pemphigoid in its clinical manifestation?

A

Similar = thick bullae at the subepidermal level

Different = IgA disease affects the mucous membranes whereas Bullous Pemphigoid dosesn’t.

34
Q

What drugs can cause Linear IgA Disease?

A
  • Vancomycin
  • Penicillin Antibiotics
  • Antihypertensives (e.g. captopril)
  • Anticonvulsants

(Linear IgA disease settles once the drugs are stopped)

35
Q

How is Linear IgA Disease treated?

A

Dapsone

Colchicine may occasionally be needed.

It improves spontaneously after 3-4 years without medication

36
Q

What areas of the body are usually affected by dermatitis herpetiformis?

A

Skin around the buttocks, elbows and scalp.

37
Q

What disease is dermatitis herpetiformis associated with?

A

Coeliac Disease

38
Q

What are the histological findings in dermatitis herpatitis?

A

IgA is deposited in the skin

39
Q

People with dermatitis herpetiformis have an increased risk of what condition?

A

Lymphoma

40
Q

Who usually gets dermatitis herpetiformis?

A

Middle aged men

(but women can get it too)

41
Q

What condition is this?

A

Dermatitis Herpetiformis

42
Q

What is the treatment for dermatitis herpetiformis?

A

Gluten Free Diet

Dapsone is also useful

43
Q

If someone has dermatitis herpetiformis, what antibodies should be tested for to help confirm the condition?

A
  • Anti-Gliadin antibodies
  • Anti-Endomysial Antibodies
44
Q

Summarise the Diagnosis of Blistering Disorders

A
  1. Is the patient an infant or child?
    • Infant - think genetic causes of blistering. Consider Epidermolysis Bullosa Acquisita (EBA)
    • Child - Consider Bullous Impetigo if crusted and rupture easily. If they are grouped vesicles in rings, consider chronic bullous disease of childhood - take a biopsy for histology and Direct-IMF.
  2. In adults
    • Tense Bullae
      • Pregnant - consider Pemphigoid Gestationis.
      • Elderly - Bullous Pemphigoid
    • Flaccid Bullae that rupture easily - Pemphigus Vulgaris
    • Grouped Itchy vesicles on elbows, buttocks or knees. = consider Dermatitis Herpetiformis.
45
Q
A