Urticaria & Angioedema

Question 1

urticaria is characterized by . . .

Answer 1

rapid onset of lesions called wheals

Question 2

wheal

Answer 2

• central mid-dermal swelling w/ or w/o surrounding erythema w/ associated pruritus
• lasts from 30 min. - 24 hrs
• they blanch

Question 3

angioedema

Answer 3

• deeper swelling (dermis and SQ tissue) w/i skin or mucous membranes
• ill defined
• lasts up to 72 hrs
• may be itchy, painful, or asx

Question 4

areas commonly affected by angioedema

Answer 4

• face (eyelids and perioral sites)
• hands
• feet
• genitalia
• tongue, uvula, soft palate, larynx

Question 5

respiratory involvement of angioedema

Answer 5

-may target GI and/or resp. tract causing abd pain, coryza, asthma, obstruction, anaphylaxis and hypotension

Question 6

2 subsets of angioedema

Answer 6

• deep urticaria w/ or w/o hives

- hereditary / ACE inhibitor associated

Question 7

deep urticaria w/ or w/o hives

Answer 7

• angioedema d/t the reaction of histamine release

- pruritis may be significant feature

Question 8

hereditary / ACE inhibitor associated angioedema

Answer 8

• hereditary: associated w/ acquired C1 esterase inhibitor deficiency
• not pruritic and no hives
• pain sx are predominant

Question 9

duration of urticaria: chronic vs. acute

Answer 9

• acute urticaria: < 6 weeks

- chronic urticaria: > 6 weeks

Question 10

pathophys of urticaria

Answer 10

-mast cell degranulation w/ release of histamine

w/ ACE associated and hereditary the mediator is bradykinin

Question 11

what kinds of stimuli can lead to mast cell activation?

Answer 11

• infections
• drugs
• foods
• inhalants
• emotional stress
• systemic dz

Question 12

what major systemics diseases can lead to mast cell activation?

Answer 12

• lupus erythematosus

- thyroid disease

Question 13

MC causes of acute urticaria

Answer 13

• infections

- adverse reactions to medications

Question 14

Chronic urticaria

Answer 14

• F>M
• idiopathic > autoimmune
• hives can stick around from weeks to years

Question 15

physical urticaria

Answer 15

• a form of chronic urticaria
• MC in ages 17-40
• caused by a physical stimulus leading to mast cell degranulation

Question 16

dermatographism

Answer 16

• shearing forces on skin

- may present as urticarial lesions at site of scratching

Question 17

cold urticaria

Answer 17

• sudden exposure to cold incites stimulus

- occurs during rewarming

Question 18

delayed pressure urticaria

Answer 18

• 4-6 hr after prolonged pressure

- MC on palms and soles

Question 19

heat urticaria

Answer 19

direct contact w/ a warm object incites stimulus

Question 20

cholinergic urticaria

Answer 20

-rise in core body temp secondary to exercise, hot water, or stress

Question 21

contact urticaria

Answer 21

contact w/ chemicals found in food, plants, medicines

Question 22

solar urticaria

Answer 22

UV or visible light

Question 23

aquagenic urticaria

Answer 23

• very rare

- caused by contact w/ water of any temp.

Question 24

what to r/o for urticaria

Answer 24

• urticarial vasculitis
• bullous pemphigoid
• urticaria pigmentosa
• papular urticaria (bug bites)

Question 25

urticarial vasculitis

Answer 25

- causes persistent urticaria-like plaques that lasts> 24 hrs and resolve w/ bruising, non-blanching - painful > itchy - bx to differentiate

Question 26

urticaria pigmentosa

Answer 26

- localized tan "mole" that swells and itches when stimulated - doesn't move

Question 27

presentation of papular urticaria aka bug bites

Answer 27

- grouped or linear | - in a "breakfast, lunch, dinner" pattern

Question 28

clinical steps if urticaria is acute and recurrent

Answer 28

- consider food diary | - order RAST to detect specific IgE

Question 29

clinical evaluation of angioedema in absence of urticaria

Answer 29

-measure C4/C1-esterase inhibitor b/c it's likely CI esterase def., hereditary or ACE-I

Question 30

clinical eval in chronic urticaria

Answer 30

- ask about: thyroid dz, CTD, infection, jaundice, hepatitis, Lyme, sinus, strep, UA, dental films - order: CBC w/ diff, CMP, ANA, TSH, thyroid ABs, hepatitis panel

Question 31

what is the mainstay of tx for acute urticaria?

Answer 31

- antihistamines: - 2nd generation are non drowsy - 1st gen cross the BBB and cause drowsiness - use until sx are controlled then 4-6 weeks more

Question 32

other txs for acute urticaria

Answer 32

- stop the causative drug - start hypoallergenic products - prednisone taper if severe - ice, cool baths - refer to allergy - epinephrine for anaphylaxis

Question 33

oral 2nd generation antihistamine options

Answer 33

- cetirizine - loratidine - fexofenadine - desloratadine - levocetirizine - nightly Singular

Question 34

what to r/o in chronic urticaria

Answer 34

physical utricaria w/ challenge test

Question 35

Tx of chronic urticaria

Answer 35

- antihistamines - doxepin - singular - hydroxychloroquine - prednisone - cyclosporine - cellcept - dapsone - xolair

Question 36

omalizumab (xolair)

Answer 36

- monocolonal antibody directed against IgE w/ low toxicity - good for those resistant to antihistamines - new drug