Derm - Urticaria

Question 1

What is urticaria also called?

Answer 1

Hives

Question 2

What is urticaria?

Answer 2

Transient itchy raised wheals on the skin

Question 3

What is urticaria associated with?

Answer 3

Transient erythematous wheals
Can be localised or generalised

Question 4

What is the pathophysiology of hives?

Answer 4

Mast cell degranulation → release of histamine and other mediators

May be allergic or autoimmune in chronic spontaneous urticaria

Question 5

What are the causes of acute urticaria?

Answer 5

• Food allergy
• Drug allergy
• Viral infection
• Insect bites or stings
• Contact allergens (e.g. latex, chemicals)
• Physical triggers (e.g. dermatographism)

Question 6

What is chronic urticaria?

Answer 6

Urticaria lasting >6 weeks

Often autoimmune with autoantibodies activating mast cells → histamine release

Question 7

How is chronic urticaria sub-classified?

Answer 7

Depends on the cause
Chronic spontaneous urticaria
Chronic inducible urticaria

Question 8

What is chronic idiopathic urticaria?

Answer 8

Recurrent episodes of chronic urticaria without a clear underlying cause of trigger

Question 9

What is chronic inducible urticaria?

Answer 9

Episodes of chronic urticaria induces by certain triggers

Question 10

What can chronic inducible urticaria be triggered by?

Answer 10

Sunlight
Temperature change
Exercise
Strong emotions
Hot or cold weather
Pressure

Question 11

What can cause autoimmune urticaria?

Answer 11

Autoimmune thyroid disease
Systemic lupus erythematosus

Question 12

How is urticaria managed?

Answer 12

Second-generation antihistamines

Fexofenadine first-line for chronic urticaria

Short course oral corticosteroids for severe flare

Question 13

In problematic urticaria what specialist treatment can be used?

Answer 13

Anti-leukotrienes e.g. montelukast
Omalizumab
Cyclosporin

Question 14

How is acute urticaria defined?

Answer 14

Lasts < 6 weeks

Question 15

How is chronic urticaria defined?

Answer 15

Lasts ≥ 6 weeks

Question 16

What is angioedema?

Answer 16

• Deeper swelling of dermis/subcutaneous tissue
• Commonly lips, eyelids, tongue
• May occur with or without urticaria

Question 17

What features suggest anaphylaxis rather than simple urticaria?

Answer 17

Airway swelling
Breathing difficulty
Hypotension
Wheeze
Collapse

Question 18

What is the next step if standard-dose antihistamine does not control chronic urticaria?

Answer 18

Increase antihistamine dose (up to 4× standard)

Question 19

Key difference between urticaria and erythema multiforme?

Answer 19

Urticaria → transient wheals, no fixed lesions
EM → fixed target lesions

Question 20

When are routine blood tests indicated in urticaria?

Answer 20

Chronic urticaria
Systemic symptoms
Features suggesting autoimmune disease