Chronic urticaria
Background
- Recurrent urticaria at least twice per week for 6 weeks [1]
- Often autoimmune etiology
Types
- Physical [2]
- Contact
- Dermatographism
- Cold
- Cholinergic (heat, exercise, stress)
- Autoimmune
- SLE
- Juvenile rheumatoid arthritis
- Graves disease
- Malignant
Clinical Features
- Hives and/or angioedema
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: antidepressants
- Doxepin [3]
- Start at 10 mg daily and increase to 10 mg TID [4]
- Avoid if recent MI
- Avoid if liver dysfunction
- Mirtazapine
- 15 mg daily [5]
- Doxepin [3]
- Consider corticosteroids
- methylprednisolone 125mg IV/IM OR prednisone 60mg PO
Disposition
- Discharge if no concern for anaphylaxis
See Also
External Links
References
- ↑ Grattan, et al, Chronic urticaria; PMID: 22345759
- ↑ Sachdeva, S, et al; Chronic Urticaria; PMID: 22345759
- ↑ Simons FE, et al; Histamine and H1-antihistamines: celebrating a century of progress. PMID: 22035879
- ↑ Yadav, S, et al; Management of difficult urticaria. PMID: 20161863
- ↑ Bigatà X, et al; Severe chronic urticaria: response to mirtazapine. PMID: 16243165