Autoimmune skin conditions

Question 1

What is tuberous sclerosis?

Answer 1

Autosomal dominant disorder that affects multiple systems - characterised by cellular hyperplasia, tissue dysplasia and hamartomas (benign malformation that looks like a tumour)

Question 2

What is the most common genodermatoses (inherited skin condition)?

Answer 2

Neurofibromatosis Type 1

Question 3

What is the 2nd most common genodermatoses?

Answer 3

Tuberous sclerosis

Question 4

Which genes are affected in tuberous sclerosis?

Answer 4

TSC1 gene and TSC2 gene

Question 5

How does tuberous sclerosis present?

Answer 5

Ash leaf macules - depigmented macules
periungual fibromas - tumours around the nails
facial angiofibromas - fibrous tissue in blood vessels in the face
Hamartomas in heart, lung, kidneys etc
Bone cysts

Question 6

Investigations for tuberous sclerosis?

Answer 6

Genetic testing for mutation of TSC1 and 2 genes

Question 7

What is pemphigus vulgaris?

Answer 7

autoimmune blistering condition causing intra-epidermal blisters -IgG autoantibodies against desmosomes cause cells in the epidermis to not stick together very well

Question 8

Which age of patients are more likely to be affected by pemphigus vulgaris?

Answer 8

Middle aged

Question 9

How does pemphigus vulgaris typically present?

Answer 9

Multiple painful FRAGILE blisters
Affects mucous membranes
Erosions due to blisters being so fragile

Question 10

What is the best investigation for pemphigus vulgaris and what would it show?

Answer 10

Immunofluorescence - IgG deposition within the epidermis

Question 11

Management of pemphigus vulgaris?

Answer 11

High dose corticosteroids

Question 12

What is the difference between pemphigus vulgaris and bullous pemphigoid?

Answer 12

Pemphigus vulgaris = middle aged people with intra-epidermal blisters (more superficial)
Bullous pemphigoid = elderly people with sub epidermal blisters (deeper)

Question 13

What is bullous pemphigoid?

Answer 13

Autoimmune blistering condition causing sub-epidermal blisters - IgG autoantibodies act against hemidesmosomes in the demoepidermal junction which causes it to break away

Question 14

Which age of patients are more likely to be affected by bullous pemphigoid?

Answer 14

Elderly people

Question 15

How does bullous pemphigoid typically present?

Answer 15

Tense blisters on inflamed skin

Blisters can be itchy

Question 16

What is the best investigation for bullous pemphigoid and what would it show?

Answer 16

Immunofluorescence - IgG and complement deposition on the basement membrane

Question 17

Management for bullous pemphigoid?

Answer 17

local disease = topical steroids

systemic disease = oral corticosteroids +/- tetracycline

Question 18

What is dermatitis herpetiformis?

Answer 18

Autoimmune blistering disorder strongly associated with gluten intolerance

Question 19

Explain the pathophysiology of dermatitis herpetiformis?

Answer 19

Blisters form due to autoantibodies against TTG (same antibody in coeliac disease)

Question 20

What is the relationship between coealic disease and dermatitis herpetiformis?

Answer 20

Only a few coeliacs will get DH but everyone who gets DH is a coeliac

Question 21

How does dermatitis herpetiformis typically present?

Answer 21

Lots of small, intensely itchy blisters on extensor surfaces:

• elbows
• forearms
• knees
• buttocks
• face and scalp

Question 22

What would be seen in blood tests, immunofluorescence and biopsy in dermatitis herpetiformis?

Answer 22

Bloods: Anti-TTG
Immunofluorescence: IgA deposits within papillae of epidermis
Biopsy: sub-epidermal blisters with papillary micro abscesses

Question 23

Management of dermatitis herpetiformis?

Answer 23

Gluten free diet +/- dapsone

Question 24

What is erythema nodosum?

Answer 24

Painful erythematous nodules on shins due to systemic disease (IBD, TB, sarcoidosis)

Question 25

How does erythema nodosum typically present?

Answer 25

Painful erythematous nodules on shins

+/- systemic upset and joint pain

Question 26

Management of erythema nodosum?

Answer 26

treat underlying cause + supportive treatment

Question 27

What would present with patchy hair loss with exclamation hair marks?

Answer 27

Alopecia areata