Urticaria

Question 1

What is urticaria and how is it characterized?

Answer 1

A vascular reaction of the upper dermis marked by transient, slightly elevated patches (wheals) that are redder or paler than the surrounding skin, often with severe itching.

Question 2

What causes the pathophysiology of urticaria?

Answer 2

Release of histamine and other vasoactive substances from mast cells and basophils in the dermis.

Question 3

What is the most benign form of anaphylaxis related to urticaria?

Answer 3

Acute IgE-mediated urticaria.

Question 4

What are some known causes of acute urticaria?

Answer 4

Infections, foods, drugs, environmental factors, latex, skin pressure, cold, heat, emotional stress, exercise, pregnancy.

Question 5

What is the first line of therapy for acute urticaria?

Answer 5

Older, sedating antihistamines that block H1 receptors, such as diphenhydramine and hydroxyzine.

Question 6

What should be done if acute urticaria persists for more than 24-48 hours?

Answer 6

Prescribe minimally sedating antihistamines like fexofenadine, loratadine, desloratadine, cetirizine, and levocetirizine, and possibly a brief course of oral corticosteroids.

Question 7

Why was the 8-month-old advised to avoid eggs after the follow-up visit?

Answer 7

To follow the egg allergy, as sIgE testing was positive for egg white.

Question 8

What is the typical duration for acute urticaria to resolve?

Answer 8

Usually within 24 hours but may last up to 6 weeks.

Question 9

What are the two medications with the most evidence for treating refractory chronic urticaria (CU)?

Answer 9

Omalizumab and cyclosporine

Question 10

Why might alternative therapies for refractory CU be less favored?

Answer 10

They have lower levels of evidence supporting their use.

Question 11

What is the primary symptom of urticaria that results from histamine release?

Answer 11

Intense pruritus (itching).

Question 12

What is the primary characteristic of chronic urticaria (CU)?

Answer 12

Recurring hives without an inciting event.

Question 13

What should be included in the work-up for acute urticaria?

Answer 13

A careful history and physical examination to find the etiology; laboratory studies are generally not indicated.

Question 14

What is a common requirement for some anti-inflammatory agents used in CU treatment?

Answer 14

Laboratory monitoring for adverse effects

Question 15

What percentage of chronic urticaria cases are autoimmune?

Answer 15

Up to 50%.

Question 16

What are some common triggers for cholinergic urticaria?

Answer 16

Emotional stress, heat, or exercise.

Question 17

What was the outcome for the patient after starting omalizumab?

Answer 17

No hives after 2 months

Question 18

What is the etiology of chronic urticaria in most patients?

Answer 18

Undetermined in at least 80-90% of patients.

Question 19

Why was omalizumab chosen for the patient in the case study?

Answer 19

The patient was not responding to high dose H1/H2 blockers and montelukast, and experienced sedation with other antihistamines.

Question 20

What are the typical physical exam findings in chronic urticaria?

Answer 20

Blanching, raised, palpable wheals that are transient and migratory.

Question 21

What initial treatment was given to the patient in the case study?

Answer 21

Benadryl 25 mg every 12 hours.

Question 22

What is the next step in treatment if Benadryl is not effective?

Answer 22

Start a second-generation antihistamine, Zyrtec 10 mg daily.

Question 23

What additional medication can be added if Zyrtec alone is insufficient?

Answer 23

Famotidine 20 mg BID.

Question 24

What should be done if symptoms persist despite treatment?

Answer 24

Consult Allergy/Immunology and consider omalizumab or cyclosporine.

Question 25

What basic laboratory studies might be included in the work-up for chronic urticaria?

Answer 25

CBC with differential, CMP, ESR, CRP, TSH, H. pylori, LFTs.