Pemphigoid

Question 1

Define pemphigoid.

Answer 1

Bullous pemphigoid is a chronic, acquired autoimmune blistering disease characterised by auto-antibodies against hemidesmosomal antigens, resulting in the formation of a sub-epidermal blister.

Question 2

What is the aetiology for pemphigoid?

Answer 2

Autoimmune sub-epidermal blistering skin diseases include the bullous pemphigoid group of diseases (bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, linear IgA disease, cicatricial pemphigoid, and anti-p200, anti-p105, and anti-p450 pemphigoid), epidermolysis bullosa acquisita, and dermatitis herpetiformis.

With the exception of dermatitis herpetiformis, all these disorders are characterised by circulating and tissue-bound auto-antibodies against various components of the dermal-epidermal anchoring complex. Antibody binding to various proteins within this complex results in dermal-epidermal separation and tense blister formation.

Question 3

What are the risk factors for pemphigoid?

Answer 3

Age 60 to 90 years

Major histocompatibility complex (MHC) class II allele (DQB1*0301)

Male

Question 4

Summarise the epidemiology of pemphigoid.

Answer 4

The prevalence of bullous pemphigoid in the US is reported as 6 to 10 cases per million, with a mean age of onset of 65 years.

VERY RARE

Question 5

What are signs and symptoms of pemphigoid?

Answer 5

Pruritus

Tense blisters on normal or erythematous skin

Erythematous or urticarial plaques

Oral lesions - mucosal involvement

Question 6

What are investigations for pemphigoid?

Answer 6

Skin biopsy for histopathological evaluation with light microscopy

Skin biopsy for direct immunofluorescence testing

Indirect immunofluorescence test on serum

Question 7

What is the management for pemphigoid?

Answer 7

Topical corticosteroids or topical tacolimus
Antihistamines
Cyclosporin

Question 8

What are complications associated with pemphigoid?

Answer 8

Corticosteroid-induced osteoporosis

Secondary infection

Death

Question 9

What is the prognosis for pemphigoid?

Answer 9

Most patients go into clinical remission with appropriate treatment. Nevertheless, mortality is considerable among older patients, with an estimated death rate between 6% and 41% in the first year.