Nonsedating antihistamines are the first-choice treatment for all forms of urticaria. In patients with recalcitrant urticaria who do not respond to conventional doses of antihistamines, current guidelines recommend increasing doses by up to 4 times in order to obtain better control of the disease. Although few studies have been conducted, there are convincing data from controlled trials for cetirizine, levocetirizine, and desloratadine that support the use of increased doses of such drugs in unresponsive patients. The use of higher doses of antihistamines has not been associated with increased adverse effects or somnolence. More studies with other second-generation antihistamines are required in order to improve the treatment of patients with severe, recalcitrant urticaria.

Key words: Antihistamines. Cetirizine. Desloratadine. Fexofenadine. Levocetirizine. Rupatadine. Urticaria.