Chronic urticaria
Background
- Recurrent urticaria at least twice per week for 6 weeks [1]
- Often autoimmune etiology
Clinical Features
- Urticaria
Differential Diagnosis
Acute allergic reaction
- Allergic reaction/urticaria
- Anaphylaxis
- Angioedema
- Anxiety attack
- Asthma exacerbation
- Carcinoid syndrome
- Cold urticaria
- Contrast induced allergic reaction
- Scombroid
- Shock
- Transfusion reaction
Evaluation
- Rule out anaphylaxis
- Identify any causative agents
Management
- H1/H2 blockers
- 2nd line agents
- Doxepin [2]
- Start at 10 mg daily and increase to 10 mg TID [3]
- Mirtazapine
- Doxepin [2]
- Consider corticosteroids
- methylprednisolone 125mg IV/IM OR prednisone 60mg PO
Disposition
- Discharge if no concern for anaphylaxis