Urticaria, Angioedema, and Anaphylactic Reactions Lecture

Question 1

Urticaria Lesions

Answer 1

Capillary vasodilationr esults in the trasudation of fluid into the surrounding tissues
Hives: raised, defined, erythematous, pruritic, round oval lesion that varies in number and size
Several hives can converge to a large plaque

Question 2

Physical urticaria

Answer 2

Exercise
Aquagenic (reaction to water)
Cholinergic (reaction to body heat)
Delayed pressure (reaction to undergarments or belt)
Heat: reaction to hot foods or objects
Solar
Adrenergic: reaction to adrenaline

Question 3

Clinical presentation and symptoms of urticaria

Answer 3

Acute: onset occurs 12-36 hours and resolves in 1-3 days
Chronic: defined as hives lasting greater than 6 weeks, can last from months to years

Question 4

Dermagraphism

Answer 4

Hives produced by scratching

Question 5

Angioedema Clinical presentation

Answer 5

Thick plaques or hives that extend into the dermis and subq tissue
Pruritus (itching) is less because there are less sensory receptors located in the derm or subq

Question 6

Angioedema Areas

Answer 6

Skin, lips, eyes, GI tract mucosa, extremities, scrotal swelling

Question 7

Anaphylaxis

Answer 7

Acute onset of skin and mucosal lesions that may progress to GI symptoms, respiratory involvement, peripheral involvement, shock and death
- Feel hot, flushed and difficulty breathing and possibly hives present

Question 8

Anaphylaxis treatment

Answer 8

Epinephrine (with signs of facial or respiratory involvement)
EpiPen Dual Pack
Epipen Jr

Question 9

Epinephrine Dosage

Answer 9

0.2-1 mL SC or IM

Question 10

EpiPen Dual Pack Dosage

Answer 10

One dose of 0.30 mg

Question 11

EpiPen Jr Dosage

Answer 11

One dose 0.15 mg

Question 12

First Generation H1 Antagonists

Answer 12

Hydroxyzine
Diphenhydramine
Cyproheptadine

Question 13

Second Generation H1 Antagonists

Answer 13

Fexofenadine
Desloratadine
Loratadine
CETIRIZINE

Question 14

Antihistamine do what?

Answer 14

Block effects of histamines (decrease vasodilation, hives and flare reactions, and pruritus (itching)

Question 15

H2 Antagonists

Answer 15

Ranitidine

Famotadine

Question 16

Ranitidine

Answer 16

150 mg BID PO

50 mg IV

Question 17

Famatadine

Answer 17

20 mg BID

50 mg IV

Question 18

Hydroxyzine

Answer 18

10-25 mg BID to QID
Max: 50 mg QID
Sedating

Question 19

Diphenhydramine

Answer 19

25-50 mg BID
Single dose up to 100 mg
MAX: 50 mg QID
Sedating

Question 20

Cyproheptadine

Answer 20

4 mg TID to QID
MAX: 8 mg QID
Sedating

Question 21

Fexofenadine (allegra)

Answer 21

180 mg QD
MAX 180 BID
Non-Sedating

Question 22

Desloratadine (Clarinex)

Answer 22

5 mg QD
MAX 10 mg QD
Non-Sedating
Syrup

Question 23

Loratadine (Claritin)

Answer 23

10 mg QD
MAX 20 mg BID
Non-Sedating
Syrup

Question 24

Cetrizine (Zytrec)

Answer 24

10 mg QD
MAX 10 mg BID
Non-Sedating
Syrup

Question 25

Antihistamine Side effects First Generation

Answer 25

CNS Sedation in elderly (short term only) and stimulation in children
Anticholinergic (dry mouth, constipation, blurred vision, dizziness)
Weigh gain (cyproheptadine)

Question 26

Corticosteroids

Answer 26

Prednisone or methylprednisolone dose pack
- Urticaria (difficult to control cases of extensive involvement), signs of angioedema or anaphylaxis, given with antihistamines

Question 27

Prednisone

Answer 27

40-60 mg QD for 5-10 days

Taper dose: 60 mg QD for 5 days, 40 mg QD for 5 days, 20 mg QD for 5 days

Question 28

Mendrol Dose Pack Instructions

Answer 28

21 four mg pills
6 days long
Take 6 tablets the first day and decrease by 1 tablet every day after
Take at meal times

Question 29

Solu-Mederol (methylprednisolone)

Answer 29

125 mg IV or IM
Anaphylatic reactions or severe cases of angioedema
Severe facial swelling, respiratory distress or difficulty swallowing

Question 30

Doxepin

Answer 30

Tri-cyclic antidepressant with potent H1 and H2 histamine blockade activity

• Chronic urticaria
• Anticholinergic effects (dry mouth and constipation)

Question 31

Doxepin dosage

Answer 31

10-25 mg TID

MAX 25-75 mg

Question 32

Methotrexate

Answer 32

Corticosteroid resistant chronic urticaria

Debilitating symptoms

Question 33

Methotrexate dosage

Answer 33

2.5 mg BID for 3 days

Question 34

EpiPen

Answer 34

Prefilled, automatic injection device for single use
Into thigh area and hold for a few seconds
Injects through clothes
Two doses may be needed
Go to ER

Question 35

Acute Urticaria Treatment Plan

Answer 35

1) Moderate to severe pruritus: one a day non-sedating antihistamine every morning and a sedating every night
2) Non-sedating H1 receptor antagonists plus H2 receptor antagonists
3) Oral corticosteroid

Question 36

Chronic Urticaria Treatment Plan First Line

Answer 36

1) Antihistamine
- Hydroxyzine
- Nonsedating in the AM and hydroxyzine at bed
2) Doxepin

Question 37

Chronic Urticaria Treatment Plan Second Line

Answer 37

1) Leukotriene inhibitors (zafirlukast, montelukast)
2) Corticosteroids- tapering
3) Dapsone
4) Cyclosporine (after luekotriene inhibitors, oral steroids, and dapsone failure)

Question 38

Angioedema Treatment Plan

Answer 38

Antihistamine + steroid (diphenhydramine or hydroxyzine plus prednisone or medrol dose pack)
- Epinephrine 0.3 mg IM or SQ
- Diphenhydramine 50 mg IV/IM
- Methylprednisolone 125 mg IV/IM
- H2 antagonist
STOP causative agent

Question 39

Epinephrine

Answer 39

Adult or patients > 66kg: 0.3-0.5 mg

Children or patients <66 kg: 0.15 mg (MAX 0.3 mg)

Question 40

Anaphylaxis Treatment Management

Answer 40

Epinephrine
Onset of 3-5 minutes, give every 15 minutes until respiratory/cardio SX resolve and improvement is seen
Saline 2L bolus (hypertension)
Cutaneous reaction respond to IM steroids or antihistamines
Biphasic prevent: IM or oral dose of corticosteroids