urticaria

Question 1

what is urticaria

Answer 1

hives

Question 2

what is the presentation of urticaria

Answer 2

pruritic, circumscribed, erythematous raised plaques
blanch completely when pressure is applied
may have central pallor
occasionally accompanied by angiodema

Question 3

when are sx of urticaria more severe

Answer 3

at night

Question 4

what shape are hives

Answer 4

round, oval or irregular

Question 5

what causes acute urticaria

Answer 5

sometimes presumptive trigger

Question 6

what causes chronic urticaria

Answer 6

often idiopathic

Question 7

what age group commonly gets urticaria

Answer 7

wide age distribution

Question 8

what part of the body is affected most by urticaria

Answer 8

any body part can be affected

waistbands + axilla are more dramatic in presentation

Question 9

what is the role of angioedema in urticaria

Answer 9

sometimes present

indicates involvement of deeper SQ tissue (face, lips, extremities +/- genitals)

Question 10

what percent of the US has had acute urticaria? chronic?

Answer 10

acute- 20%

chronic- 1%

Question 11

when do lesions of acute urticaria resolve

Answer 11

usually within 24hrs, self-limiting

present for <6wks

Question 12

which gender experiences acute urticaria more frequently

Answer 12

neither

men = women

Question 13

how often does chronic urticaria occur

Answer 13

most days for >6wks

Question 14

in which decades of life does chronic urticaria usually occur

Answer 14

4th + 5th decades

Question 15

which gender experiences chronic urticaria more frequently

Answer 15

women

Question 16

etiology of urticaria

Answer 16

no specific etiology

infections- viral, bacterial, parasitic
allergic- meds, stings, latex, foods, environment (heat, cold, pressure), transfusion rxns
systemic disorders- urticarial vasculitis (non-blanching lesions), cutaneous small vessel vasculitis, autoimmune (SLE, sjogrens, celiac dz, autoimmune thyroid dz)

Question 17

diagnosis of urticaria

Answer 17

not indicated in new onset cases which do not suggest underlying disorder
consider to r/o underlying illness if hx is suggestive (CBC w diff, ESR/CRP, UA, LFTs)
if allergic- serum test for IgE antibodies, refer to allergist/immunologist

Question 18

treatment goals of acute-new onset urticaria

Answer 18

short-term relief of pruritis + angioedema if present
treat anaphylaxis/emergent cases prn
2/3 will resolve spontaneously (often w.o scarring)

Question 19

medications for acute-new onset urticaria

Answer 19

H1 antihistamines:

• -1st gen- benadryl (diphenhydramine)
• -2nd gen- zyrtec (cetirizine), claritin (loratidine)

H2 blockers

• -zantac (ranitidine)
• -pepcid (Famotidine)

steroids- brief course to control persistent + severe sx, do not inhibit mast cells but suppress contributing inflam mechanisms

Question 20

counseling for chronic urticaria

Answer 20

rarely permanent- 50% resolve in 1yr
rarely puts pts in any acute risk
sx can be managed
avoid triggers

Question 21

medications for chronic urticaria

Answer 21

steroids- rescue therapy to attain control of severe sx

H1 antihistamines:

• -1st gen- benadryl (diphenhydramine)
• -2nd gen- zyrtec (cetirizine), claritin (loratidine)

H2 blockers:

• -zantac (ranitidine)
• -pepcid (famotidine)

Question 22

step-wise approach to treating chronic urticaria w meds

Answer 22

1) 2nd gen H1 at standard dose
2) advance dose of 2nd gen H1
3) add H2 blocker
4) add leukotriene inhibitor
5) add 1st gen H1 at bedtime
6) advance dose of 1st gen H1 gradually

**When sx are controlled- continue for min 2-3mo before beginning to taper