[5] Urticaria Flashcards Preview

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Flashcards in [5] Urticaria Deck (30)
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1
Q

What is urticaria also known as?

A

Hives

2
Q

What is urticaria?

A

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

3
Q

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

A

Angiography-oedema

4
Q

What can urticaria be classified into?

A
  • Acute

- Chronic

5
Q

What is acute urticaria?

A

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

6
Q

What is chronic urticaria?

A

Where the rash persists for > 6 weeks

7
Q

What cause urticaria?

A

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

8
Q

What is the effect of histamine release in the skin?

A

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

9
Q

What can sometimes underly urticaria?

A

An identifiable trigger

10
Q

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

A

About half

11
Q

What are some possible triggers of acute urticaria?

A
  • Allergies
  • Viral infections
  • Skin contact with chemicals, nettles, latex etc.
  • Physical stimuli
12
Q

What allergies can cause urticaria?

A
  • Food
  • Bites
  • Stings
  • Medication
13
Q

What physical stimuli can cause acute urticaria?

A
  • Firm rubbing
  • Pressure
  • Cold
  • Heat
14
Q

What are the different subtypes of chronic urticaria?

A
  • Chronic spontaneous urticaria
  • Autoimmune urticaria
  • Inducible urticaria
15
Q

What are the triggers of chronic spontaneous urticaria?

A
  • Medication
  • Stress
  • Infection
16
Q

What are the triggers for inducible urticaria?

A
  • Aquagenic
  • Exercise or emotion (cholinergic)
  • Exposure to cold or heat
17
Q

What are the risk factors for urticaria?

A
  • Hay fever

- Asthma

18
Q

Describe a typical urticaria lesion?

A

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

19
Q

Are urticaria lesions uniform?

A

No they can vary in size and shape

20
Q

What can urticaria lesions be associated with?

A

Swelling of soft tissues (angioedema)

21
Q

How long do the individual wheals last in urticaria?

A

Come and go within a few hours

22
Q

How is urticaria diagnosed?

A

Clinically

23
Q

What clinical sign identifies urticaria?

A

Wheals only lasting a few hours

24
Q

What investigations may be required in chronic urticaria?

A
  • FBC
  • ESR
  • CRP
  • Physical challenge e.g. cold provocation
  • Patch testing/prick testing
25
Q

What are the differentials for urticaria?

A
  • Erythema multiforme
  • Dermatitis herpetiformis
  • Pemphigoid
  • Erysipelas
  • Eczema
  • Urticaria pigmentosa
  • Chronic pruritis
26
Q

How can urticaria be managed?

A
  • Identify and treat cause
  • Minimise aggravating factors
  • Topical anti-pruritic agents
  • Non-sedating H1 antihistamines
  • Short course oral steroids if severe
27
Q

What are possible aggravating factors for urticaria?

A
  • Overheating
  • Stress
  • Alcohol
  • Caffeine
28
Q

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

A
  • Calamine lotion

- Topical menthol 1%

29
Q

What antihistamines are typically used in urticaria?

A

Cetirizine or loratidine

30
Q

What are the potential complications of urticaria?

A
  • Insomnia
  • Depression
  • Poor quality of life