High-dose desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard-dose treatment in patients with acquired cold urticaria: A randomized, placebo-controlled, crossover study

Background: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. Objective: We sought to assess the effects of 5 and 20 mg of desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. Methods: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of desloratadine, and 20 mg of desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. Results: Compared with placebo, 7 days of desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of desloratadine. Conclusions: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of desloratadine without an increase in AEs. This study supports current guidelines that increased desloratadine dosing might benefit patients with urticaria who do not respond to standard doses. (J Allergy Clin Immunol 2009;123:672-9.)