Bullous pemphigoid

Question 1

What is bullous pemphigoid?

Answer 1

A subepidermal blister caused by an autoimmune reaction.

Question 2

Aetiology of bullous pemphigoid?

Answer 2

Autoimmune

Patient typically elderly (>60 years).

Question 3

Underlying pathophysiology of bullous pemphigoid?

Answer 3

Anti-hemidesmosome antibodies (IgG) react with an antigen of the hemidesmosomes anchoring basal cells to basement membrane - Type 2 hypersensitivity.

Question 4

Symptoms of bullous pemphigoid?

Answer 4

Pruritis (itch) - may occur weeks or months before the appearance of any visible skin lesion.

Well-demarcated erythematous plaques may occur weeks to months before the blisters.

Large, tense extremely itchy blisters on normal skin or erythematous base.

Question 5

Sign of bullous pemphigoid?

Answer 5

Blisters will be nikolsky sign negative.

A skin finding in which the top layers of the skin slip away from the lower layers when rubbed.

Question 6

Investigations for bullous pemphigoid?

Answer 6

Biopsy

• Immunoflorescense: shows linear IgG and complement deposited around the dermo-epidermal junction.

Bloods: autoantibodies (antiBP180)

Question 7

Management of local disease?

Answer 7

High potency topical steroids on onset of symptoms e.g. itch

Question 8

Management of systemic disease?

Answer 8

Oral steroids e.g. prednisolone +/- tetracycline antibiotics e.g. doxycycline+/- antihistamine

- Tetracyclines used as steroid sparing agents - anti-inflammatory effect 

 - Antihistamines used for sedating and anti-puritic properties. 

If no response - immunosupression (azathioprine/methotrexate).