Pharmacologic Treatment of Chronic Spontaneous Urticaria

First-Line Treatment: Second-Generation H1-Antihistamines

The American Academy of Allergy, Asthma, and Immunology recommends starting with standard-dose second-generation H1-antihistamines as monotherapy for the treatment of chronic spontaneous urticaria (CSU) 1
Second-generation H1-antihistamines are preferred over first-generation antihistamines due to their superior safety profiles and reduced sedation 1
The British Society for Allergy and Clinical Immunology suggests offering at least two different non-sedating antihistamines to each patient, as individual responses and tolerance vary significantly between agents 2
Available options for second-generation H1-antihistamines include cetirizine, desloratadine, fexofenadine, levocetirizine, loratadine, mizolastine, bilastine, rupatadine, and ebastine 2, 3
Cetirizine has the shortest time to maximum concentration, which may be advantageous when rapid symptom control is needed 2

The American College of Allergy, Asthma, and Immunology recommends increasing the dose of second-generation H1-antihistamines up to 4 times the standard dose if symptoms remain inadequately controlled after 2-4 weeks of standard-dose treatment 1, 4
Adjusting the timing of medication to ensure highest drug levels coincide with anticipated urticaria activity may be beneficial 2

The American Academy of Allergy, Asthma, and Immunology recommends adding omalizumab 300mg subcutaneously every 4 weeks if symptoms remain inadequately controlled despite up-dosed antihistamines 1, 4
The standard starting dose of omalizumab is 300mg every 4 weeks, and patients should be allowed up to 6 months to demonstrate response before considering treatment failure 4, 1

The British Society for Allergy and Clinical Immunology suggests adding cyclosporine (up to 5mg/kg body weight) to the second-generation H1-antihistamine regimen if inadequate control persists with omalizumab after 6 months 1, 3
Cyclosporine is effective in approximately 65-70% of patients with severe autoimmune urticaria, and optimal patient selection includes those with positive autologous serum skin test (ASST) 5

The American College of Allergy, Asthma, and Immunology recommends adding montelukast to H1-antihistamine for poorly controlled urticaria, though evidence for monotherapy is limited 5, 2
H2-antihistamines may provide additional benefit when added to H1-antihistamines, though in practice may be more helpful for accompanying dyspepsia 2

The American Academy of Allergy, Asthma, and Immunology recommends using the Urticaria Control Test (UCT) to assess disease control, with scores ranging 0-16 (higher scores indicate better control) 1, 6
Once complete symptom control is achieved, maintaining the effective dose for at least 3 consecutive months before considering step-down is recommended 1
Reducing the daily dose by no more than 1 tablet per month during step-down, and returning to the last effective dose if symptoms recur, is advised 1