Bullous pemphigoid

Question 1

What is bullous pemphigoid?

Answer 1

This is an autoimmune immunobullous condition in which the immune system causes a breakdown of the dermo-epidermal junction, leading to blistering (Bullae formation)

Question 2

What are some diseases associated with bullies pemphigoid?

Answer 2

Stroke
Dementia
Parkinson’s disease
Internal malignancy
Other autoimmune disorders

Question 3

What are some drugs that can cause bullous pemphigoid?

Answer 3

• Diuretics
• Analgesics
• Antibiotics
• Potassium iodide
• Gold
• Captopril

Question 4

Describe the pathophysiology of bullous pemphigoid

Answer 4

This is caused by the patients circulating IgG antibodies reacting with antigens (e.g. BPAG1/2) in the basement membrane and hemidesmosomes, which anchor the basal cells to the basement membrane

This results in loacl complement activation and tissue damage

Fluid and some inflammatory cells can then move into the dermo-epidermal space forming sub-epidermal bullae

Dermal papillae will also project into the bulla

Question 5

How does bullous pemphigoid usually present?

Answer 5

Large, tense bullae either on normal skin or with an erythematous base

This is usually generalised, but in 15-30% of cases, they will be localised

The bullae may burst to leave erosions and itchy, erythematous plaques and papules may form

Nikolsky sign will be negative (Lateral pressure on the skin next to the blister causes it to extend)

Question 6

What condition is shown?

Answer 6

Bulls pemphigoid

Question 7

From where is a biopsy of a blister taken?

Answer 7

From across the edge of the blister, collecting both normal and abnormal skin

Question 8

What test is performed on normal skin in bullous pemphigoid?

Answer 8

Immunofluorescence

Question 9

What test is performed on abnormal skin in bullous pemphigoid?

Answer 9

H and E staining

Question 10

What will H and E staining show in bullous pemphigoid?

Answer 10

Question 11

What will immunofluorescence show in bullous pemphigoid?

Answer 11

IgG banding around the basement membrane

Question 12

How is localised bullous pemphigoid usually treated?

Answer 12

Very potent topical steroids
Emollients
Antiseptic washes
Dermovate ointment
Possible blister deflation

Question 13

How is generalised bullous pemphigoid treated?

Answer 13

• Oral steroids (Prednisolone 40-80mg/day)
• Tetracyclines
• Azathioprine
• Dapsone
• Ciclosporin

Question 14

How long will bullous pemphigoid usually take to remit?

Answer 14

3-6 months