Urticaria/Angioedema

Question 1

What is urticaria?

Answer 1

Also known as hives or wheals, which is in basic terms oedema in the dermis

Question 2

How quickly does urticaria develop?

Answer 2

Over a few minutes

Question 3

What is the difference between urticaria and angioedema?

Answer 3

Urticaria is intensely itchy, whereas angioedema is rarely itchy

Question 4

What are features of an urticarial rash?

Answer 4

Develop acutely over a few minutes

• Cutaneous swellings/weals
• Intense pruritis
• No surface change or scaling
• Erythematous
  
  • If very acutely swollen, may appear flesh-coloured or whitish and people often mistake them for blisters.

Question 5

What are features of angioedema?

Answer 5

Soft tissue swelling (oedema) especially around the eyes, the lips and the hands but this is rarely itchy

Question 6

What is the pathogenesis of urticaria?

Answer 6

Degranulation of cutaneous mast cells which releases a number of inflammatory mediators (including histamine) which in turn make the dermal and sub-dermal capillaries leaky. In most cases the underlying cause is autoimmune (patients develop autoantibodies against the high-affinity IgE receptor α-subunit of the mast cell).

Question 7

What are phsyical causes of urticaria?

Answer 7

• Cold
• Deep pressure
• Stress
• Heat
• Sunlight
• Chemical irritants

Question 8

How would you manage someone with acute urticaria (<6 weeks)?

Answer 8

• Treat underlying cause - remove cause
• Avoid salicylates/opiates/NSAIDs - make it worse
• Oral antihistamines - certrizine

Question 9

How would you manage angioedema?

Answer 9

If not hereditary:

• IM adrenaline
• IV steroids

Question 10

What is hereditary angioedema?

Answer 10

A rare autosomal dominant condition due to an inherited deficiency of C1 esterase inhibitor (C1-INH) which causes massive activation of the complement system, increased bradykinin levels and thus angio-oedema

Question 11

What are features of hereditary angioedema?

Answer 11

• Attacks of non-itchy cutaneous angioedema - lasts for 72 hours
• Recurrent abdo pain
• NO URTICARIA

Question 12

How would you manage someone with an acute attack of hereditary angioedema?

Answer 12

• C1 esterase inhibitor
• FFP
• Noveal agents - Icatibant, Ecallantaide

Question 13

What maintenance treatment would you use for hereditary angioedema?

Answer 13

Anabolic steroids - increase hepatic synthesis of C1 esterase inhibitor

Question 14

How would you manage someone with chronic urticaria?

Answer 14