September 5th, 2011

1. Urticaria

2. Urticaria
• Superficial swellings of dermis →
wheals
 Itchy, pale in center → pink
superficial plaques, resolve over
hours without a mark.
 Surrounding flare is due to an axon
reflex.

7. Urticaria
• Deep swellings of dermis & subcutaneous &
submucosal tissues → Angioedema
 Painful, rather than pruritic and
take longer time to resolve.
• Wheals & angioedema often coexist, but
may occur alone.

13. The spectrum of urticaria
I. Ordinary urticaria:• Acute
• Chronic (recurrent ≥6 weeks):
- idiopathic (50%) - autoimmune (25-50%).
II. Physical urticaria (35%)
• Adrenergic urt. • Dermographism (8.5%)
• Aquagenic urt. • Exercise-induced anaphylaxis
• Cholinergic urt. • Localized heat urt.
• Cold urt. • Solar urt.
• Delayed pressure urt. • Vibratory angioedema
III. Contact urticaria: biologic, chemical.
IV. Urticarial vasculitis (proved by skin biopsy)
V. Angioedema (without wheals)

14. Urticarias
Potential Provoking Factors
1. Drugs: penicillin, aspirin, sulfonamides,
NSAIDs, ….
2. Foods (eggs, fish, strawberries, milk, … etc.) &
food additives (Azo dyes, benzoates,
penicillin).

15. Urticarias
Potential Provoking Factors (C ont.)
3. Inhalants: e.g. pollen grains, house dust,
feathers.
4. Infections e.g. focal sepsis in tonsils, teeth or
sinuses, or urinary tract infections.
Recently, Helicobacter pylori has been suggested.

16. Urticarias
Potential Provoking Factors (C ont.)
5. Infestations: Intestinal worms.
6. Emotional stress especially in cholinergic
urticaria.
7. Systemic disease: SLE, lymphomas,
thyrotoxicosis.

17. Urticarias
• Heterogeneous group of disorders.
• Sudden appearance of itchy red transient
wheals.
Episodes of wheals “wheal come & go” for duration
Less than 6 wks More than 6 wks
Acute Chronic