Urticaria

1. URTICARIA
Dr. Owen Ngalamika
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2. 2

3. • Urticaria is a vascular reaction of the skin
characterized by the appearance of
wheals and associated with severe itching,
stinging, or pricking sensations
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4. classification
1. Acute urticaria:
Duration - <6 weeks,
Triggers – 50% idiopathic, 40% viral URI,
9% drugs, 1% food
Common in children with atopic dermatitis
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5. 2. Chronic urticaria:
Duration >6 weeks and continuous (occurs
at least 2x/week when off of treatment)
Associations with HLA-DR4 and HLA-DQ8,
H. pylori gastritis, and intestinal
strongyloidiasis
Triggers; 60% ordinary (autoimmune,
psedoallergic, infection-related, idiopathic),
35% physical, 5% vasculitic
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6. 3. Episodic urticaria:
Duration >6 weeks but not continuous
4. Physical urticaria: induced by exogenous
physical stimulus; lesions occur within
minutes of provocation and generally
resolve <2 hours and are localized to the
stimulated area
Examples include dermatographism,
cholinergic, cold, heat, solar, pressure,
exercise-induced, vibratory, and aquagenic
urticaria
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7. Clinical features
• Multiple pruritic whealsof different sizes
erupt anywhere on the body and ten fade
within 2-24 hours without bruising; often
appears in evening or upon waking; most
intense at night
• In severe cases can be associated with
fatigue, lassitude, sweats, chills,
indigestion, arthralgias
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10. epidemiology
• Occurs at any age
• More common in women: chronic urticaria,
dermatographism, cold urticaria
• More common in men: pressure urticaria
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11. pathogenesis
• Increased release of histamine from mast
cells situated around the capillaries
• Increased capillary permeability
• Other substances besides histamine may
cause vasodilation and capillary
permeability (serotonin, leukotrienes,
prostaglandins, proteases, and kinins)
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12. Etiologic factors
• Drugs (most frequent cause of acute
urticaria) e.g. penicillin, aspirin
• Food – e.g. chocolate, shellfish, nuts,
peanuts, tomatoes, strawberries, melons,
pork, cheese, garlic, onions, eggs, milk,
and spices
• Food additives – yeast, dyes
• Infections – URTI (streptococcal), H.
pylori, Hepatitis B and C, helminths
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13. • Emotional stress – severe emotional
stress may exacerbate urticaria
• Menthol – found in mentholated cigarettes,
candy and mints, cough syrup, aerosol
sprays, and topical medications
• Neoplasms – urticaria has been
associated with carcinomas and hodgkin
disease
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14. • Inhalants – grass pollens, house dust
mites, feathers, formaldehyde, soybean
dust, cottonseed, animal dander,
cosmetics, aerosols, etc
• Alcohol: alcohol-induced mast cell
stimulation
• Hormonal imbalance: urticaria twice as
common among women than men
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15. • Genetics: polymorphisms in the β2
adrenergic receptor gene have been
identified in aspirin-intolerant acute
urticaria
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16. diagnosis
• Usually made on clinical grounds
• Lesions in a fixed location for more than
24h suggest the possibility of urticarial
vasculitis, urticarial phase of an
immunobullous eruption, EM, granuloma
annulare, sarcoidosis, or CTCL
• If individual wheals last for longer than
24hrs, a skin biopsy should be performed
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17. Treatment
• Antipruiritic lotions and avoidance of
triggers
• First line: Antihistamines
• Second line: systemic corticosteroids
• Third line: immunotherapy (for severe
refractory autoimmune urticaria only);
IVIG, cyclosporine, plasmapheresis
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18. ANGIOEDEMA
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19. • Angioedema is an acute, evanescent,
circumscribed edema that usually affects
the most distensible tissues, such as the
eyelids, lips, earlobes, and external
genitalia, or mucous membranes of the
mouth, tongue, or larynx
• The swelling occurs in the deeper parts of
the skin or in the subcutaneous tissues
and as a rule is only slightly tender, with
the overlying skin unaltered, edematous,
or, rarely ecchymotic 19

20. • There may be diffuse swelling on the
hands, forearms, feet, and ankles
• Frequently the condition begins during the
night and is found on awakening
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23. epidemiology
• Hereditary form is autosomal dominant
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24. pathogenesis
• Hereditary AE: mutation in structural gene
for C1 inhibitor leading to:
- reduced quantity (type 1)
- reduced function (type 2)
• Acquired AE: secondary to formation of
inhibitory autoantibodies against C1 INH
or persistent low-level activation of C1q
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25. Clinical features
• Can merge with wheals, especially at eyelids
• Can be a feature of anaphylaxis if the throat is
involved
• Hereditary AE: low C4
• Acquired AE: low C4 and low C1q
• Vibratory AE: hereditary (AD) or acquired;
vibratory stimulus (jogging, motorcycles) lead to
localized swelling and erythema in minutes
• Food/exercise-induced anaphylaxis: occurs
within minutes of exercise after prior ingestion of
specific foods or within 4 hours of a heavy meal
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26. treatment
• As in urticaria
• For C1 esterase inhibitor deficiency
- Emergency: give C1 inhibitor concentrate
or FFP (life saving)
- Antihistamines, corticosteroids, and
epinephrine do not work
- Treatment of choice: anabolic steroids
(stanozolol or danazol)
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27. URTICARIAL VASCULITIS
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28. Epidemiology
• Usually affects middle-aged women
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29. Clinical features
• Considered an urticarial dermatosis and
not urticaria
• Lesions last > 24 hrs (unlike urticaria)
although clinically appears like urticaria
• Lesions are pruritic and/or painful (burning
sensation)
• Often occurs at pressure points and may
resolve with residual purpura
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30. • 40% develop angioedema; 50% develop
arthralgia
• Course is unpredictable
• Acute hemorrhagic edema of childhood:
urticarial vasculitis with prominent
cutaneous hemorrhage in young children
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32. pathology
• Evidence of leukocytoclastic vasculitis,
fibrinoid deposits in/around blood vessels,
extravasation of red cells, endothelial cell
swelling, perivenular cellular infiltrate rich
in neutrophils
• Need to biopsy a lesion that is < 24 hours
old for accuracy
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33. treatment
• No universally effective therapy
• Antihistamines are usually insufficient
except in mild cases
• 50% improve with NSAIDs
• Isolated positive reports with colchicine,
dapsone, hydroxychloroquine
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34. thanks
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