Urticaria Flashcards
What is urticaria characterised by?
by appearances of wheels, hives and/or angio-oedema
What is the epid of urticaria?
affects 10-25% of the population
What are RF for urticaria?
strong FHx
What are possible causes for urticaria?
- Food allergic
- Drug eruptions
- Infection-related urticaria
- Insect bites
- Allergic and irritant contact dermatitis
What is urticaria in systemic disease?
- Cholinergic (heat induced)
- Adrenergic (stress induced)
- Atopic dermatitis
How do Hives appear clinically?
- Pruritic
- Burning pale swellings of superficial dermis that last up to 24h
- Erythemous, blanching, odematous, non painful
- Swelling of face, tongue or lips
When and where does angio-oedema swelling occur?
swelling involving deeper layers of sub dermis and occurs with urticaria in 40% cases
What are possible DDx of urticaria?
- Anaphylaxis
- Dermatographism
- Atopic dermatitis
- Urticarial vasculitis
What investigations do you do for urticaria?
- FBC with differential to establish baseline eosinophilia count
- ESR
- CRP
- C4 LEVEL: decreased in hereditary and acquired angio-oedema
What is management of urticaria?
Depends if airway involvement (antihistamine)
How long does it take for urticaria to resolve?
24h and leave no residual markings but sometimes more Acute<6weeks
Chronic>6weeks
What is acute urticaria?
lasts less than 6 weeks due to hypersensitivity reaction to specific trigger
What is chronic urticaria?
characterised by daily or near-daily episodes of hives occurring for 6 weeks or more
What are possible complications of urticaria?
- Excoriations
- Sedation
- Skin Infections
What is the lifetime prevalence of urticaria?
approximately 20%
