1. Acute Urticaria
1-1. Course and management
Acute urticaria is generally self-limited and often improves with minimal intervention.
1-2. Antihistamines
- First-generation antihistamines (e.g., hydroxyzine, diphenhydramine) are effective but may cause sedation.
- Second-generation antihistamines (e.g., loratadine, fexofenadine, cetirizine) are equally effective and preferred due to less sedation.
1-3. Severe episodes
Intramuscular epinephrine (1:1,000, 0.01 mg/kg, maximum 0.5 mg) may be administered for acute, severe urticaria or angioedema, though it is rarely needed.
1-4. Corticosteroids
A short course of oral corticosteroids may be considered for severe cases unresponsive to antihistamines.
2. Inducible Urticaria
2-1. Primary management
Avoidance of the triggering stimulus is the most effective approach, though it can be challenging (e.g., in cholinergic urticaria).
2-2. Antihistamines
Antihistamines, with dose escalation when necessary, should be tried in all cases, though response rates vary.
3. Chronic Urticaria
3-1. Mainstay therapy
Non-sedating or low-sedating H1 antihistamines are the first-line treatment.
If symptoms persist, up-dosing up to four times the standard dose may be considered.
3-2. Adjunctive agents
Addition of H2 antihistamines or leukotriene receptor antagonists (e.g., montelukast) may be considered, though evidence of benefit is limited.
3-3. Corticosteroids
Short courses of oral corticosteroids may help in poorly controlled cases, but long-term use is not recommended.
3-4. Biologic therapy
Omalizumab (anti-IgE monoclonal antibody) is FDA-approved for chronic urticaria in patients 12 years and older.
3-5. Other immunomodulators
Off-label agents include cyclosporine, tacrolimus, mycophenolate, dapsone, hydroxychloroquine, sulfasalazine, and azathioprine.