Urticaria

Question 1

Define Urticaria?

Answer 1

Itchy, red, blotchy rash resulting from swelling of the superficial part of the skin
Angiooedema occurs when the deep tissues, the lower dermis and subcutaneous tissues are involved and become swollen
AKA hives

Question 2

What is the aetiology of Urticaria?

Answer 2

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 leads to erythematous apperance

Question 3

What are the possible triggers for Acute Urticaria?

Answer 3

Allergies (foods, bites, stings)
Viral Infections
Skin Contact with chemicals
Physical Stimuli

Question 4

What are the possible triggers for Chronic Urticaria?

Answer 4

Chronic Spontaneous Urticaria - medication, stress, infections
Autoimmune

Question 5

What is the epidemiology of Urticaria?

Answer 5

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

Question 6

What are the presenting symptoms and signs of Urticaria?

Answer 6

Central itchy white papule or plaque surrounded by erythematous flare
Lesions vary in size and shape
May be associated with swelling of the soft-tissues of the eyelids, lips and tongue (angiooedema)
Individual lesions are usually transient

Question 7

What is the timescale for Acute Urticaria?

Answer 7

Symptoms develop quickly but normally resolve within 48 hrs

Question 8

What is the timescale for Chronic Urticaria?

Answer 8

Rash persists for > 6 weeks

Question 9

What investigations would you do for Urticaria?

Answer 9

Usually clinical

Tests may be required for chronic urticaria (e.g. FBC, ESR/CRP, patch testing, IgE tests)