Bullous Disorders

Question 1

In pemphigus valgaris is the level of blistering intra-epidermal or sub-epidermal?

Answer 1

Intra-epidermal (s=superficial)

Question 2

In bullous pemphigoid is the level of blistering intra-epidermal or sub-epidermal?

Answer 2

Sub-epidermal (d=deep)

Question 3

What could the investigations be for blistering caused by infection?

Answer 3

Bacterial microscopy & culture
PCR - HSV, VZV
Viral culture
Serology

Question 4

What would the investigation be for blistering caused by porphyria?

Answer 4

Porphyrin studies

Question 5

What would the investigation be for blistering caused by contact dermatitis?

Answer 5

Patch testing

Question 6

What would the investigations be for blistering caused by an autoimmune disorder?

Answer 6

Biopsy with IMF (immunofluorescence)

Question 7

Name 3 autoimmune bullous diseases?

Answer 7

Bullous pemphigoid
Pemphigus vulgaris
Dermatitis herpetiformis (DH)

Question 8

What is Nikolsky sign?

Answer 8

Slight rubbing of the skin results in exfoliation of the outermost layer (Nikolsky sign positive)

Question 9

Describe bullous pemphigoid?

Answer 9

Large tense bullae on normal skin or erythematous base

Question 10

Is bullous pemphigoid Nikolsky sign positive or negative?

Answer 10

Negative

Question 11

Describe the pathogenesis of bullous pemphigoid?

Answer 11

Circulating antibodies (IgG) react with antigens in the basement membrane (BM) and hemidesmosomes anchoring basal cells to BM

Question 12

What would a biopsy with IMF show in bullous pemphigoid?

Answer 12

Linear IgG and complement deposited around the BM

Question 13

What is the treatment for localised bullous pemphigoid?

Answer 13

Topical potent steroids

Question 14

What is the treatment for generalised bullous pemphigoid?

Answer 14

Oral prednisolone (40-80mg/day) combined with an oral immunosuppressant (e.g. azathioprine, ciclosporin) or tetracycline

Question 15

Describe pemphigus vulgaris?

Answer 15

Flaccid vesicles/bullae on scalp, face, axillae, groins

Question 16

Is pemphigus vularis Nikolsky sign positive or negative?

Answer 16

Positive

Question 17

Describe the pathogenesis of pemphigus vulgaris?

Answer 17

IgG antibodies are directed against intercellular adhesions

Question 18

What would a biopsy with IMF show in pemphigus vulgaris?

Answer 18

Cell surface bound IgG, chicken wire pattern in epidermis

Question 19

What is acantholysis? (a process common to all variants of pemphigus)

Answer 19

Acantholysis is the loss of intercellular connections, such as desmosomes, resulting in loss of cohesion between keratinocytes

Question 20

What is the treatment for local pemphigus vulgaris?

Answer 20

Topical steroids

Topical anaesthetics

Question 21

What is the treatment for systemic pemphigus vulgaris?

Answer 21

Prednisolone +/- azathioprine

Question 22

Dermatitis herpetiformis is associated with what other autoimmune disease?

Answer 22

Coeliac disease

Question 23

Describe dermatitis herpetiformis?

Answer 23

Small blisters on erythematous urticarial base with itch

Question 24

What is the pathophysiology of dermatitis herpetiformis?

Answer 24

IgA autoantibodies to gluten tissue transaminase in the gut and epidermis

Question 25

In dermatitis herpetiformis is the level of blistering intra-epidermal or sub-epidermal?

Answer 25

Sub-epidermal

Question 26

What are the investigations for dermatitis herpetiformis?

Answer 26

1. Coeliac serology - IgA antibodies to tissue transglutaminase (tTG) 2. Histology 3. Small intestinal scope + biopsy - partial or subtotal villous atrophy

Question 27

What would a biopsy with IMF show in dermatitis herpetiformis?

Answer 27

Granular IgA in dermal papillary tips

Question 28

What is the treatment for dermatitis herpetiformis?

Answer 28

Gluten-free diet + Dapsone

Question 29

What needs to be checked before a patient is put on dapsone and why?

Answer 29

Blood glucose-6-phosphate dehydrogenase levels as a deficiency increases the risk of haemolysis due to dapsone

Question 30

What is a recognised complication of dermatitis herpetiformis?

Answer 30

Small bowel lymphoma