[5] Urticaria

Question 1

What is urticaria also known as?

Answer 1

Hives

Question 2

What is urticaria?

Answer 2

An itchy, red, blotchy rash resulting from swelling of the superficial part of the skin

Question 3

What can also occur in urticaria if there is involvement of deeper tissues?

Answer 3

Angiography-oedema

Question 4

What can urticaria be classified into?

Answer 4

• Acute

- Chronic

Question 5

What is acute urticaria?

Answer 5

Symptoms develop quickly but resolve quickly (often within 48 hours)

Question 6

What is chronic urticaria?

Answer 6

Where the rash persists for > 6 weeks

Question 7

What cause urticaria?

Answer 7

Activation of mast cells in the skin causing the release of histamine and other mediators

Question 8

What is the effect of histamine release in the skin?

Answer 8

Capillary leakage causing swelling of the skin and vasodilation causing the erythematous rash

Question 9

What can sometimes underly urticaria?

Answer 9

An identifiable trigger

Question 10

In what proportion of acute urticaria cases is a trigger identified?

Answer 10

About half

Question 11

What are some possible triggers of acute urticaria?

Answer 11

• Allergies
• Viral infections
• Skin contact with chemicals, nettles, latex etc.
• Physical stimuli

Question 12

What allergies can cause urticaria?

Answer 12

• Food
• Bites
• Stings
• Medication

Question 13

What physical stimuli can cause acute urticaria?

Answer 13

• Firm rubbing
• Pressure
• Cold
• Heat

Question 14

What are the different subtypes of chronic urticaria?

Answer 14

• Chronic spontaneous urticaria
• Autoimmune urticaria
• Inducible urticaria

Question 15

What are the triggers of chronic spontaneous urticaria?

Answer 15

• Medication
• Stress
• Infection

Question 16

What are the triggers for inducible urticaria?

Answer 16

• Aquagenic
• Exercise or emotion (cholinergic)
• Exposure to cold or heat

Question 17

What are the risk factors for urticaria?

Answer 17

• Hay fever

- Asthma

Question 18

Describe a typical urticaria lesion?

Answer 18

Central, itchy white papule or plaque (wheal) surrounded by an erythematous flare

Question 19

Are urticaria lesions uniform?

Answer 19

No they can vary in size and shape

Question 20

What can urticaria lesions be associated with?

Answer 20

Swelling of soft tissues (angioedema)

Question 21

How long do the individual wheals last in urticaria?

Answer 21

Come and go within a few hours

Question 22

How is urticaria diagnosed?

Answer 22

Clinically

Question 23

What clinical sign identifies urticaria?

Answer 23

Wheals only lasting a few hours

Question 24

What investigations may be required in chronic urticaria?

Answer 24

• FBC
• ESR
• CRP
• Physical challenge e.g. cold provocation
• Patch testing/prick testing

Question 25

What are the differentials for urticaria?

Answer 25

• Erythema multiforme
• Dermatitis herpetiformis
• Pemphigoid
• Erysipelas
• Eczema
• Urticaria pigmentosa
• Chronic pruritis

Question 26

How can urticaria be managed?

Answer 26

• Identify and treat cause
• Minimise aggravating factors
• Topical anti-pruritic agents
• Non-sedating H1 antihistamines
• Short course oral steroids if severe

Question 27

What are possible aggravating factors for urticaria?

Answer 27

• Overheating
• Stress
• Alcohol
• Caffeine

Question 28

What are some anti-pruritic agents that can be used in urticaria?

Answer 28

• Calamine lotion

- Topical menthol 1%

Question 29

What antihistamines are typically used in urticaria?

Answer 29

Cetirizine or loratidine

Question 30

What are the potential complications of urticaria?

Answer 30

• Insomnia
• Depression
• Poor quality of life