Urticaria

Question 1

What is urticaria?

Answer 1

Urticaria (AKA hives) consists of erythematous, blanching, oedematous, non-painful, pruritic lesions that develop rapidly, usually over minutes
- Typically lasts less than 24 hours and leaves no residual skin markings upon resolution

Question 2

What are the different types of urticaria a patient may present with?

Answer 2

1. Acute Urticaria → mainly allergy related (IgE-mediated)
2. Chronic Urticaria → may be triggered by heat, cold, pressure, sunlight, vibration, acetylcholine release, and water

Question 3

What is “angiooedma”?

Answer 3

“swelling that is similar to hives, but the swelling is under the skin instead of on the surface.”
* Angiooedema occurs when the deep tissues, the lower dermis and subcutaneous tissues are involved and become swollen.
* Angio-oedema occurs in association with urticarial in about 40% of cases

Question 4

What causes urticaria?

Answer 4

• Caused by activation of mast cells in the skin, resulting in the release of histamines
• The cytokine release leads to capillary leakage, which causes swelling of the skin and vasodilation –> erythematous appearance
• Aspirin is a common cause of urticaria

Question 5

What are some possible triggers of urticaria?

Answer 5

1. ACUTE urticaria
   * Allergies (foods, bites, stings)
   * Viral infections
   * Skin contact with chemicals
   * Physical stimuli
2. CHRONIC urticaria
   * Chronic spontaneous urticaria - medication, stress, infections
   * Autoimmune

Question 6

Summarise the epidemiology of urticaria

Answer 6

• 15% of general population experience urticaria at some point in life
• Acute is much more common than chronic urticaria

Question 7

What are the presenting symptoms/ signs of urticaria?

Answer 7

• Erythematous Oedematous Lesions → pale, pink, smooth raised skin (wheals)
• Pruritus
• Resolution within 24 hours
• Swelling of face, tongue, or lips → up to 40% of urticaria cases have associated angio-oedema
• Lesions blanch when palpated

Question 8

What investigations are used to diagnose/ monitor urticaria?

Answer 8

ESR & CRP→ if urticarial vasculitis suspected 

Question 9

How is urticaria managed?

Answer 9

1. Trigger identification & avoidance
2. 1st Line → Antihistamines (loratadine)- non- sedating
   - In acute urticaria a sedating antihistamine (e.g. chlorphenamine) may be considered for night-time use for troublesome sleep symptoms
3. Systemic Corticosteroid (Prednisolone) → for severe or recurrent episodes

Question 10

What complications may arise following urticaria?

Answer 10

excoriations, sedation (side effect of antihistamines), skin infections

Question 11

Describe the prognosis of urticaria

Answer 11

excellent, vast majority of patients respond well to therapy with non-sedating antihistamines, and the condition is short-lived