Urticaria (acute, chronic)

Question 1

Define urticaria

Answer 1

Itchy, red, blotchy rash resulting from swelling of superficial part of skin

AKA hives

Question 2

Define angioedema & aetiology

Answer 2

Swelling of soft tissues of eyelids, lips & tongue

Occurs when the deep tissues, lower dermis & subcutaneous tissues are involved & become swollen

Question 3

Aetiology of urticaria

2

Answer 3

Caused by activation of mast cells in skin, resulting in release of HISTAMINES

Cytokine release —> capillary leakage —> swelling of skin & vasodilation —> erythematous appearance

Question 4

Possible triggers of acute urticaria

4

Answer 4

Allergies (food, bites, stings)
Viral infections
Skin contact w/ chemicals
Physical stimuli

Question 5

Possible triggers of chronic urticaria

2

Answer 5

Chronic spontaneous urticaria - medication, stress, infection
Autoimmune

Question 6

Epidemiology of urticaria

prevalence, acute vs chronic

Answer 6

15% general population experience it at some point in life

Acute urticaria much more common than chronic

Question 7

Presenting symptoms & signs of urticaria

4 + timescales of acute & chronic

Answer 7

Central itchy white papule or plaque surrounded by erythematous flare
Lesions vary in shape & size
May be associated w/ swelling of soft tissues of eyelids, lips & tongue (= angioedema)
Individual lesions usually transient

Timescales
Acute - symptoms develop quickly but normal resolve within 48 hrs
Chronic - rash persist > 6 weeks

Question 8

Investigations for urticaria

2

Answer 8

Usually clinical diagnosis

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