Disease Profiles: Blistering Skin Disorders

Question 1

Describe the clinical presentation of dermatitis herpetiformis

Answer 1

Intensely itchy symmetrical lesions on an erythematous and swollen base

Elbows, knees and buttocks often excoriated

Question 2

How would you manage systemic bullous pemphigoid?

Answer 2

Oral steriods +/- tetracycline antibiotics +/- antihistamine

If no response - immunosuppression (azathioprine/methotrexate)

Question 3

What would immunofluorescence of a sample from dermatitis herpetiformis show?

Answer 3

Granular deposits of IgA in dermal papillae

Question 4

What would histology of a sample from bullous pemphigoid show?

Answer 4

Subepidermal blisters and inflammatory infiltrates (mainly eosinophils) within the blister

Question 5

Describe the pathophysiology of bullous pemphigoid

Answer 5

Anti-hemidesmosome antibodies (IgG) react with a major and/or minor antigen of the hemidesmosomes anchoring basal cells to basement membrane

Complement is activated and causes tissue damage - derma-epidermal junction is interrupted and sub-epidermal blister forms

Question 6

Describe the management of dermatitis herpetiformis

Answer 6

Gluten free diet +/- dapsone

Question 7

What are tetracyclines used for in the management of bullous pemphigoid?

Answer 7

Steroid sparing agents

Question 8

Describe the clinical presentation of pemphigus vulgaris

Answer 8

Fluid-filled, painful, fragile blisters which rupture to form shallow erosions

Involves skin esp. scalp, face, axillae, groin, trunk, may affect mucosa e.g. mouth, respiratory tract

Question 9

How would you manage local bullous pemphigoid?

Answer 9

High potency topical steriods

Question 10

What haplotype is dermatitis herpetiformis associated with?

Answer 10

HLA-DQ2 haplotype

Question 11

What are antihistamines used for in the management of bullous pemphigoid?

Answer 11

Sedating and anti-puritic properties

Question 12

What is pemphigus vulgaris?

Answer 12

Rare autoimmune bullous disease, most common (80%) subtype of the pemphigus group

Question 13

How would you manage systemic pemphigus vulgaris?

Answer 13

High dose oral steriods + immunosuppression +/- rituximab

Question 14

Describe the pathophysiology of dermatitis herpetiformis

Answer 14

IgA antibodies target gliadin component of gluten but cross react with connective tissue matrix proteins (TTG) - leads to immune complex formation, complement activation and inflammation

Tissue damage causes the formation of sub epidermal blisters

Question 15

Which patient group is most likely to develop pemphigus vulgaris?

Answer 15

Usually presents in middle age (40-60)

Question 16

Which autoimmune blistering disorder will be Nikolsky sign positive?

Answer 16

Pemphigus Vulgaris

Question 17

What hypersensitivity reaction is responsible for the pathophysiology of bullous pemphigoid?

Answer 17

Type II

Question 18

Which investigations would you perform in suspected dermatitis herpetiformis?

Answer 18

Bloods (anti-TTG), biopsy, immunoflorescence

Question 19

What is the Nikolsky sign?

Answer 19

Blisters can be extended with gentle lateral pressure

Question 20

Describe the pathophysiology of pemphigus vulgaris

Answer 20

IgG4 antibodies against desmosomal proteins lead to loss of keratinocyte adhesion in the skin and mucous membranes

Question 21

What would a biopsy of a sample from pemphigus vulgaris show?

Answer 21

Sup-epidermal blisters with papillary micro-abscesses

Question 22

What patient group is most likely to develop bullous pemphigoid?

Answer 22

Patient typically elderly (> 60 years)

Question 23

How would you manage local pemphigus vulgaris?

Answer 23

Topical steriods + topical anaethetics

Question 24

Patients with pemphigus vulgaris have an increased risk of which malignancy?

Answer 24

Small bowel lymphoma

Question 25

What is bullous pemphigoid?

Answer 25

Subepidermal blister caused by an autoimmune reaction

Question 26

What would a biopsy of a sample from pemphigus vulgaris show?

Answer 26

Intra-epidermal blister with accumulation of inflammatory cells within the dermis

Question 27

Describe the clinical presentation of bullous pemphigoid

Answer 27

Large, tense, extremely itchy blisters on normal skin or erythematous base Typically blisters will be distributed in flexural regions of trunk or proximal limbs Well-demarcated erythematous plaques may occur weeks to months before the blisters

Question 28

What would immunofluorescence of a sample from pemphigus vulgaris show?

Answer 28

Chicken wire deposition of IgG within the epidermis

Question 29

What would immunofluorescence of a sample from bullous pemphigoid show?

Answer 29

Liner IgG and complement deposited around the basal membrane

Question 30

Which patient group is most likely to develop dermatitis herpetiformis?

Answer 30

Peak incidence 15-40 years, strong association with coeliac disease

Question 31

What is dermatitis herpetiformis?

Answer 31

Autoimmune bullous disorder associated with coeliac disease