Challenges in the management of chronic urticaria

Abstract

The term "chronic idiopathic urticaria" denotes a spectrum of conditions with different poorly understood pathogenetic mechanisms in which the release of histamine plays a role. Nonsedating second-generation H1 antihistamines are postulated to be the first line of treatment of chronic idiopathic urticaria by national and international guidelines, but as control is not always achievable with the usually recommended doses, first-generation sedating antihistamines like hydroxyzine and diphenhydramine at high daily doses (200 mg) have been proposed as an alternative before resorting to treatment with systemic corticosteroids and other potentially hazardous agents. Our long time experience and recent research give us grounds to believe that increasing the doses of nonsedating H1 antihistamines up to fourfold improves significantly the chances of successful treatment. Our data suggest that the urticaria-associated discomfort is relieved by higher than conventional doses of levocetirizine and desloratadine in about 75% of the patients and that sedation/somnolence does not seem to be a major deterrent. The dose increase also improves the urticaria-specific quality of life. Contrary to the belief that individual patients may benefit from one antihistamine or another, we demonstrate that the drug with better ability to suppress the histamine skin effects in experiments in healthy volunteers (levocetirizine) is also superior in improving the different aspects of control of chronic urticaria (subjective and objective symptoms, quality of life) and that increasing its dose of up to fourfold may even paradoxically reduce the sense of sedation/somnolence in parallel with the relief of urticaria discomfort.

Figure 1

Graphical definition of chronic urticaria.

Figure 2

Results of the study of higher than conventional doses of levocetirizine and desloratadine in difficult-to-treat urticaria (adapted from Staevska et al[25]). The darkened boxes represent the successes at conventional doses for both drugs and the light boxes represent the additional value of dose increase.