Dermatitis herpetiformis

Question 1

What is dermatitis herpetiformis?

Answer 1

This is a relatively rare autoimmune bullous condition which is strongly associated with Coeliac’s disease

Question 2

What disease is mostly associated with dermatitis herpetiformis?

Answer 2

Coeliacs disease (And HLA-DQ2 haplotype)

Question 3

How does coeliacs disease lead to dermatitis herpetiformis?

Answer 3

In coeliac’s, IgA antibodies target the gliadin component of gluten, but cross react with connective tissue matrix proteins found in the dermo-epidermal junction, causing formation of immune complexes in the dermal papillae and activating complement system and neutrophils

Question 4

Where will dermatitis herpetiformis most commonly affect?

Answer 4

• Extensor aspects of elbows and forearms
• Buttocks and scapulae
• Extensor aspects of knee
• Face and scalp

Question 5

How will dermatitis herpetiformis present?

Answer 5

Intensely itchy, symmetrical lesions
Papillary dermal micro-abscesses
Gluten sensitivity

Question 6

What condition is shown?

Answer 6

Dermatitis herpetiformis

Question 7

What tests can be used in diagnosis of dermatitis herpetiformis?

Answer 7

Small intestinal scope
Coeliac serology (tTG)
H & E staining
Immunofluorescence

Question 8

What will small intestinal biopsy show in dermatitis herpetiformis (Coeliacs)?

Answer 8

Partial or sub-total villous atrophy

Question 9

What will H&E staining show in dermatitis herpetiformis?

Answer 9

Sub-epidermal blistering and micro-abscesses in the dermal papillae

Question 10

What will immunofluorescence show in dermatitis herpetiformis?

Answer 10

Granular deposits of dermal papillary IgA

Question 11

How is dermatitis herpetiformis managed?

Answer 11

Management involves restriction to a gluten-free diet, topical steroids and dapsone

Remittance can be induced by strict gluten-free diet, but the disease is chronic

There is a possible risk of small bowel lymphoma