Urticaria

Question 1

Describe urticaria rash

Answer 1

Extremely pruritic weals (transient elevation of the skin due to dermal oedema. Pale centrally with a red rim or flare. No surface change)
Surrounded by erythema
Wide distribution over the body
Polymorphous in size and shape
Lesions change location, only last around an hour

Question 2

Describe angio-edema

Answer 2

• A deeper form of urticaria with transient swellings of the deeper dermal, subcutaneous and submucosal tissues
• Often affect the lips, tongue, eyelids, genitalia, hands or feet
• Can co-exist with urticaria

Question 3

What is acute urticaria?

Answer 3

• Urticaria that lasts <6weeks

- Usually a self limiting, one off episode

Question 4

What are causes of acute urticaria?

Answer 4

• Spontaneous
• Viral infections (in children)
• Allergies eg bites, latex, foods, drugs

Question 5

What is chronic urticaria?

What are the 3 types?

Answer 5

• Urticaria that lasts for >6 weeks, typically on most days of the week
  Can be:
  Chronic spontaneous urticaria - No known identifiable cause, but can be aggravated by heating, stress and certain drugs
  Autoimmune urticaria - Presence of IgG autoantibodies
  Chronic inducible urticaria - Physical stimulus eg water, heat, cold, exercise

Question 6

What is the UAS7?

Answer 6

• Urticaria Activity Score

- Records number of weals and severity of itching for 7 days

Question 7

What investigations would you undertake?

Answer 7

• Usually a clinical diagnosis

- Possible allergy testing

Question 8

What is the management for urticaria?

Answer 8

• Avoid possible triggers
• Symptom diaries to help find the trigger
• Non sedating histamine for up to 6 weeks (cetirizine, fexofenadine)
• If severe symptoms, 7 days oral corticosteroid in addition to anti histamine
• Referral to dermatology if painful and persistent

Question 9

What is the management for angio-edema without anaphylaxis?

Answer 9

Rapidly progressing:
Slow IV or IM chlorphenamine and hydrocortisone
Stable:
- Remove underlying remover
- Mild cases may not need treatment
- Non sedating antihistamine for up to 6 weeks
- 7 days oral corticosteroid in addition to antihistamine if severe