Urticaria

Question 1

Define urticaria.

Answer 1

Urticaria, also known as welts, hives, or wheals, is characterised by the appearance of intensely pruritic erythematous plaques. It appears clinically as pruritic, pale, blanching swellings of the superficial dermis that last for up to 24 hours.

Acute urticaria lasts less than 6 weeks and is often due to a hypersensitivity reaction to a specific trigger. Underlying viral infections are also a common cause of acute urticaria, particularly in children. Acute urticaria is generally self-limiting.

Chronic urticaria is characterised by daily or near-daily episodes of hives occurring for 6 weeks or more and has a complex aetiology.

Question 2

Explain the aetiology/risk factors of urticaria.

Answer 2

Allergy
Infection
Systemic disease
Minor physical trauma

Complex aetiology of chronic urticaria

Question 3

Summarise the epidemiology of urticaria.

Answer 3

Urticaria (chronic, acute, or both) affects 15-25% of the population at some time in their lives. The incidence of acute urticaria is higher in people with atopy, and the condition occurs most commonly in children and young adults.

Question 4

Recognise the presenting symptoms of urticaria. Recognise the symptoms of urticaria on physical examination.

Answer 4

Raised bumps
Erythema
Pruritus

Question 5

Identify appropriate investigations for urticaria and interpret the results.

Answer 5

This is usually identifiable by examination.

Investigations may be carried out in order to determine the cause of urticaria.

Question 6

What is the management of urticaria?

Answer 6

Airway protection if required

Adrenaline if required

Antihistamines

Corticosteroids

Question 7

What are the complications of urticaria?

Answer 7

Excoriations

Sedation from treatment

Skin infections

Question 8

What is the prognosis of urticaria?

Answer 8

The prognosis for patients with acute urticaria is excellent. The vast majority of patients respond well to therapy with non-sedating antihistamines, and the condition is short-lived.

Patients with chronic urticaria generally do well. Most patients can be managed with antihistamines alone; only a small sub-set of patients require additional medicines for control of symptoms.