1. The ins and outs of Hives- with apologies to bees!
Urticaria and Angioedema
Richard J Powell

2. Simple urticaria urticaria is Latin for nettle rash hives, welts,
anywhere - trunk and limbs
diverse morphology - wheal and flare
pruritic with a central raised area
erythematous halo
blanch with pressure
Resolve within 24 hours -no residuum

3. Angioedema with urticaria
same process, just deeper in tissues
occurs in extremities, digits, lips, eyelids, tongue, larynx, GI tract and genitals (in men)
painful rather than itchy

4. Urticaria and angioedema
affects 15-20%
women > men
in majority it is acute and self-limiting
<10% become chronic
Urticaria with angioedema in 50% cases
10% have angioedema alone
Rest have urticaria alone

5. Classification of urticaria
cholinergic
contact
physical - exercise, aquagenic, dermatographism, cold, solar, delayed pressure
vasculitic

6. Histamine release causes
Itching via nerve fibres
Redness - local capillary dilatation
Oedema - increased permeability

8. Acute urticaria and angioedema- in primary care handled frequently and effectively
duration < 6 weeks
more common in children
acute self-limiting character limits morbidity
mast cell degranulation
aetiology is often elusive ? viral
Can be associated with isolated exposure to allergens (food, drugs, venom, latex)
non specifically (NSAIDs, codeine, radio-contrast dyes)

9. Causes of acute urticaria and angioedema
Idiopathic
Peanuts, eggs, fish, milk, shellfish
Drugs - antibiotics, NSAIDs/aspirin
Latex and associated foods
Insect bites -wasp and bee venom, mosquitoes
Infections
Blood products and plasma expanders
Inhalant allergens- rare

10. Chronic Urticaria and Angioedema -in primary care
0.1% population
Duration >6 weeks
>50% resolve within 5 years
Rule out recurrent episodes of acute urticaria
Vexing problem
Often disabling, interfering with patient’s QOL
Worse at night - interrupts sleep

11. Chronic Urticaria and Angioedema -in primary care
50% autoimmune aetiology
Rarely a true allergy - SPT/elimination diets can help convince the patient that an allergen is not involved

12. Angioedema without hives
Idiopathic
ACE inhibitors - bradykinin
Hereditary angio(neurotic)edema (HAE) - hence family history
Acquired angioedema

13. Investigations Diagnosis based on history Headache/pain relief
Itching after intercourse, visiting dentists, balloons
Allergen specific IgE in vivo or in vitro
C4 and CI inhibitor
FBC and ESR
LFTs and TFT’s
Intra-dermal skin test with autologous serum

14. Management Avoid trigger if identified
H1 antihistamines - chronically for > 6 months
H2 antihistamines
Leukotriene receptor antagonists - monteleukast
T cell inhibitors if all else fails- cyclosporine (neoral)
Oral cortico-steroids
Rarely adrenaline
Referral for specialist opinion

15. “Some patients with chronic urticaria do not respond to conventional doses of anti-histamines and much higher than licensed doses are often used (e.g. up to 20mg with cetirizine).” NEJM 346: ;2002
“….in general it is better to achieve symptom control (and thereby a good night’s sleep) with a non-sedating preparation.” Drug and Therapeutics Aug 2002