Treatment of Urticaria
Start with a standard dose of a second-generation H1-antihistamine (such as cetirizine, loratadine, desloratadine, fexofenadine, or levocetirizine) taken once daily, and if symptoms remain inadequately controlled after 2-4 weeks, increase the dose up to 4-fold the standard dose. 1
Stepwise Treatment Algorithm
Step 1: Second-Generation H1-Antihistamines (First-Line)
- Begin with standard-dose second-generation H1-antihistamines
- These are preferred over first-generation antihistamines due to minimal sedation and better safety profile 2, 3
- Examples include: cetirizine, loratadine, desloratadine, fexofenadine, levocetirizine, mizolastine 4
- If inadequate control after 2-4 weeks (or earlier if symptoms are intolerable): increase dose up to 4-fold 1, 5
Key Point: The 2022 international guidelines emphasize an "as much as needed and as little as possible" approach, using disease control assessment (UCT score) to guide treatment escalation 1. A UCT score ≤16 indicates inadequate control requiring dose escalation.
Step 2: Add Omalizumab (Second-Line for Chronic Urticaria)
- If symptoms remain inadequately controlled on high-dose antihistamines, add omalizumab 300 mg subcutaneously every 4 weeks 1
- This step applies specifically to chronic urticaria (symptoms >6 weeks), not acute urticaria
- Allow up to 6 months for response to omalizumab 1
- If insufficient response, consider updosing: shorten interval or increase dose up to maximum of 600 mg every 2 weeks 1
- Omalizumab has superior risk-benefit profile compared to cyclosporine 1
Step 3: Add Cyclosporine (Third-Line for Chronic Urticaria)
- For patients who fail high-dose omalizumab, add cyclosporine up to 5 mg/kg body weight 1
- Only consider after inadequate response to omalizumab within 6 months (or earlier if symptoms intolerable) 1
Critical Safety Monitoring: Monitor blood pressure and renal function (BUN, creatinine) every 6 weeks while on cyclosporine due to risks of hypertension, renal failure, hirsutism, gum hypertrophy, and seizures in predisposed patients 1
Important Treatment Nuances
Acute vs. Chronic Urticaria Distinction
- Acute urticaria (lasting <6 weeks): Typically self-limited; second-generation H1-antihistamines are first-line 2, 3
- Short courses of oral corticosteroids may be used if minimal/no response to antihistamines in acute urticaria 2
- However, evidence for adding corticosteroids to antihistamines in acute urticaria is weak - two out of three RCTs showed no benefit 6
- Chronic urticaria (>6 weeks): Follow the full 3-step algorithm above; long-term corticosteroids are NOT recommended 2
Step-Down Strategy
Once complete disease control is achieved:
- Do not step down higher-than-standard antihistamine doses until at least 3 consecutive months of complete control 1
- Reduce daily dose by no more than 1 tablet per month 1
- If breakthrough symptoms occur during step-down, return to the last dose that provided complete control 1
Common Pitfalls to Avoid
- Avoid first-generation antihistamines as monotherapy due to sedation, reduced concentration, and impaired performance 4
- Avoid long-term corticosteroids for chronic urticaria - not recommended despite common misuse 2
- Don't add corticosteroids routinely to acute urticaria treatment - evidence shows minimal benefit 6
- Avoid NSAIDs and aspirin in patients with urticaria, as they can worsen symptoms 4
- Avoid ACE inhibitors in patients with angioedema without wheals; use with caution if angioedema accompanies urticaria 4
Special Populations
- Pregnancy/breastfeeding: Second-generation H1-antihistamines are preferred due to safety profile; chlorphenamine often chosen in UK due to long safety record 4, 2
- Children and older adults: Second-generation H1-antihistamines are recommended 2